0000950170-23-037931 | 10-Q | XBRL Viewer

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CONTINGENCIES AND UNCERTAINTIES - Severance Plan (Details)	6 Months Ended
	Jun. 30, 2023
Severance Plan
Period within which employee is terminated by entity without cause following a change of control	12 months
Period within which no comparable employment is offered by the entity following a change of control	30 days
Period within which employee resigns following a change of control due to material change in terms of employment	12 months
Minimum
Severance Plan
Period of base salary to be considered for severance payments	3 months
Maximum
Severance Plan
Period of base salary to be considered for severance payments	18 months

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)

6 Months Ended

Jun. 30, 2023

Accounting Policies [Abstract]

Basis of Presentation

The terms “Geron”, the “Company”, “we” and “us” as used in this report refer to Geron Corporation and its wholly-owned subsidiaries, Geron UK Limited, or Geron UK, a United Kingdom company, and Geron Netherlands B.V., or Geron Netherlands, a Netherlands company. Geron UK was incorporated in September 2021, and its operations commenced in January 2022. Geron Netherlands was incorporated in February 2023, and its operations commenced in June 2023.

The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by United States, or U.S., generally accepted accounting principles, or GAAP, for complete financial statements. In the opinion of management, all adjustments (consisting only of normal recurring accruals) considered necessary for a fair presentation have been included. Operating results for the three and six months ended June 30, 2023 are not necessarily indicative of the results that may be expected for the year ending December 31, 2023 or any other period. These unaudited condensed consolidated financial statements and notes should be read in conjunction with the audited financial statements for each of the three years ended December 31, 2022, included in our Annual Report on Form 10-K for the year ended December 31, 2022, or the Form 10-K. The accompanying condensed consolidated balance sheet as of December 31, 2022 has been derived from audited financial statements at that date.

Prior Period Reclassification

The prior period presentations of other comprehensive loss in the condensed consolidated statements of stockholders' equity and accrued liabilities have been updated to conform to current period presentation. See Note 3 on Accrued Liabilities.

Principles of Consolidation

The condensed consolidated financial statements include the accounts of Geron Corporation and its wholly-owned subsidiaries, Geron UK and Geron Netherlands. For Geron UK and Geron Netherlands, we have eliminated intercompany accounts and transactions. We prepare the financial statements of Geron UK and Geron Netherlands using the local currency as the functional currency. We translate the assets and liabilities of Geron UK and Geron Netherlands at rates of exchange at the balance sheet date and translate income and expense items at average monthly rates of exchange. The resultant translation adjustments are included in accumulated other comprehensive income (loss), a separate component of stockholders’ equity, on our condensed consolidated balance sheets.

Net Loss Per Share

Basic net income (loss) per share is calculated by dividing net income (loss) by the weighted-average number of shares of common stock outstanding for the periods presented without consideration of potential common shares. In connection with previous public offerings, we issued pre-funded warrants to purchase shares of our common stock. These pre-funded warrants are exercisable immediately at an exercise price of $0.001 per share each, and as of June 30, 2023, none of these pre-funded warrants have been exercised. These pre-funded warrants, which represent an aggregate of 51,430,477 shares of common stock, have been included in the computation of basic net loss per share, since their exercise price is negligible and they may be exercised at any time.

Diluted net income per share would be calculated by adjusting the weighted-average number of shares of common stock outstanding for the dilutive effect of additional shares of common stock that would have been outstanding if potentially dilutive securities had been issued, as determined using the treasury-stock method. Potential dilutive securities consist of outstanding stock options and warrants to purchase our common stock. Diluted net loss per share excludes potential dilutive securities for all periods presented as their effect would be anti-dilutive. Accordingly, basic and diluted net loss per share is the same for all periods presented in the accompanying condensed consolidated statements of operations. Since we incurred a net loss for the three and six months ended June 30, 2023 and 2022, the diluted net loss per share calculation excludes potential dilutive securities of 97,584,078 and 153,703,476, respectively, related to outstanding stock options and warrants as their effect would have been anti-dilutive.

Use of Estimates

The accompanying condensed consolidated financial statements have been prepared in accordance with U.S. GAAP. The preparation of financial statements in conformity with U.S. GAAP requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. On an ongoing basis, we evaluate our estimates, including those related to accrued liabilities, revenue recognition, fair value of marketable securities, operating leases, right-of-use

assets, lease liabilities, income taxes, and stock-based compensation. We base our estimates on historical experience and on various other market specific and relevant assumptions that we believe to be reasonable under the circumstances. Actual results could differ from those estimates.

Fair Value of Financial Instruments

Cash Equivalents and Marketable Securities

We consider all highly liquid investments with an original maturity of three months or less to be cash equivalents. We are subject to credit risk related to our cash equivalents and marketable securities. Our marketable debt securities include U.S. Treasury securities, government-sponsored enterprise securities, commercial paper and corporate notes.

We classify our marketable debt securities as available for sale. We record available-for-sale debt securities at fair value with unrealized gains and losses reported in accumulated other comprehensive income (loss) in stockholders’ equity. Realized gains and losses are included in interest income and are derived using the specific identification method for determining the cost of securities sold and have been insignificant to date. Dividend and interest income are recognized when earned and included in interest income on our condensed consolidated statements of operations. See Note 2 on Fair Value Measurements.

Leases

At the inception of an arrangement, we determine whether the arrangement is or contains a lease based on the unique facts and circumstances present. Operating leases are included in operating leases, right-of-use assets and lease liabilities on our condensed consolidated balance sheets. Right-of-use assets represent our right to use an underlying asset for the lease term and lease liabilities represent our obligation to make lease payments arising from the lease. Operating lease liabilities and their corresponding right-of-use assets are recorded based on the present value of remaining lease payments over the expected lease term. The present value of remaining lease payments within the 12 months following the balance sheet date are classified as current lease liabilities. The present value of lease payments not within the 12 months following the balance sheet date are classified as noncurrent lease liabilities. The interest rate implicit in lease contracts is typically not readily determinable. As such, to calculate the net present value of lease payments, we apply our incremental borrowing rate, which is the estimated rate to borrow on a collateralized basis over a similar term an amount equal to the lease payments in a similar economic environment as of the lease commencement date. We may adjust the right-of-use assets for certain adjustments, such as initial direct costs paid or incentives received. In addition, we include any options to extend or terminate the lease in the expected lease term when it is reasonably certain that we will exercise any such option. Lease expense is recognized on a straight-line basis over the expected lease term.

For lease agreements entered into after January 1, 2019 that include lease and non-lease components, such components are generally accounted for separately. We have also elected not to recognize on our condensed consolidated balance sheets leases with terms of one year or less.

Debt Issuance Costs and Debt Discounts

Debt issuance costs include legal fees, accounting fees, and other direct costs incurred in connection with the execution of our debt financing. Debt discounts represent costs paid to the lenders. Debt issuance costs and debt discounts are deducted from the carrying amount of the debt liability and are amortized to interest expense over the term of the related debt using the effective interest method.

Revenue Recognition

We recognize revenue in accordance with the provisions of Accounting Standards Codification Topic 606, Revenue from Contracts with Customers, or Topic 606. In determining the appropriate amount and timing of revenue to be recognized under this guidance, we perform the following five steps: (i) identify the contract(s) with our customer; (ii) identify the promised goods or services in the agreement and determine whether they are performance obligations, including whether they are distinct in the context of the agreement; (iii) measure the transaction price, including the constraint on variable consideration; (iv) allocate the transaction price to the performance obligations based on stand-alone selling prices; and (v) recognize revenue when (or as) we satisfy each performance obligation.

A performance obligation is a promise in an agreement to transfer a distinct good or service to the customer and is the unit of account in Topic 606. Significant management judgment is required to determine the level of effort required and the period over which completion of the performance obligations is expected under an agreement. If reasonable estimates regarding when performance obligations are either complete or substantially complete cannot be made, then revenue recognition is deferred until a

reasonable estimate can be made. Revenue is then recognized over the remaining estimated period of performance using the cumulative catch-up method.

We allocate the total transaction price to each performance obligation based on the estimated relative stand-alone selling prices of the promised goods or services underlying each performance obligation. Estimated selling prices for license rights are calculated using an income approach model and include the following key assumptions, judgments and estimates: the development timeline, revenue forecast, commercialization expenses, discount rate and probabilities of technical and regulatory success.

Following is a description of the principal activities from which we generate revenue. License fees and royalty revenue primarily represent amounts earned under agreements that out-license our technology to various companies.

License Agreements

In connection with the divestiture of Geron’s human embryonic stem cell assets, including intellectual property and proprietary technology, to Lineage Cell Therapeutics, Inc. (formerly BioTime, Inc. which acquired Asterias Biotherapeutics, Inc.) in 2013, we are entitled to receive royalties on sales of certain research or commercial products utilizing Geron’s divested intellectual property.

Royalties. For agreements with sales-based royalties, including milestone payments based on the level of sales, where the license is deemed to be the predominant item to which the royalties relate, we recognize revenue at the later of (a) when the related sales occur, or (b) when the performance obligation, to which some or all of the royalty has been allocated, has been satisfied (or partially satisfied). At each reporting date, we estimate the sales incurred by each licensee during the reporting period based on historical experience and accrue the associated royalty amount.

Restricted Cash

Restricted cash consists of funds maintained in separate money market or certificate of deposit accounts for credit card purchases.

Research and Development Expenses

Research and development expenses currently consist of expenses incurred in developing and testing imetelstat and research related to potential next generation telomerase inhibitors. These expenses include, but are not limited to, payroll and personnel expense, lab supplies, non-clinical studies, clinical trials, including support for investigator-led clinical trials, raw materials to manufacture clinical trial drugs, manufacturing costs for research and clinical trial materials, sponsored research at other labs, consulting, costs to maintain technology licenses and research-related overhead.

Our current imetelstat clinical trials are being supported by contract research organizations, or CROs, and other vendors. We accrue expenses for clinical trial activities performed by CROs based upon the estimated amount of work completed on each trial. For clinical trial expenses and related expenses associated with the conduct of clinical trials, the significant factors used in estimating accruals include the number of patients enrolled, the number of active clinical sites, and the duration for which the patients have been enrolled in the trial. We monitor patient enrollment levels and related activities to the extent possible through internal reviews, review of contractual terms and correspondence with CROs. We base our estimates on the best information available at the time. However, additional information may become available to us which will allow us to make a more accurate estimate in future periods. In that event, we may be required to record adjustments to research and development expenses in future periods when the actual level of activity becomes more certain.

Depreciation and Amortization

We record property and equipment at cost and calculate depreciation using the straight-line method over the estimated useful lives of the assets, generally four years. Leasehold improvements are amortized over the shorter of the estimated useful life or remaining term of the lease.

Stock-Based Compensation

We maintain various stock incentive plans under which stock options and restricted stock awards can be granted to employees, non-employee directors and consultants. We also have an employee stock purchase plan for all eligible employees. We recognize stock-based compensation expense based on grant-date fair values of service-based stock options on a straight-line basis over the requisite service period, which is generally the vesting period. For performance-based stock options with vesting based on the

achievement of certain strategic milestones, stock-based compensation expense is recognized over the period from the date the performance condition is determined to be probable of occurring through the date the applicable condition is expected to be met and is reduced for estimated forfeitures, as applicable. If the performance condition is not considered probable of being achieved, no stock-based compensation expense is recognized until such time as the performance condition is considered probable of being met, if at all. If the assessment of probability of the performance condition changes, the impact of the change in estimate would be recognized in the period of the change. The determination of grant-date fair values for our service-based and performance-based stock options and employee stock purchases using the Black Scholes option‑pricing model is affected by our stock price as well as assumptions regarding a number of complex and subjective variables. The grant-date fair value for service-based restricted stock awards is determined using the fair value of our common stock on the date of grant. We evaluate whether an adjustment to the assumptions of fair value of our common stock and historical volatility are required if observed prices of our common stock materially differ from historical information.

The following table summarizes the stock-based compensation expense included in operating expenses on our condensed consolidated statements of operations related to stock options and employee stock purchases for the three and six months ended June 30, 2023 and 2022, which was allocated as follows:


	Three Months Ended June 30,				Six Months Ended June 30,
(In thousands)	2023		2022		2023		2022
Research and development	$	1,590	$	1,012	$	2,896	$	1,867
General and administrative	$	2,355		1,046	$	4,010		1,883
Stock-based compensation expense included in operating expenses	$	3,945	$	2,058	$	6,906	$	3,750

As stock-based compensation expense recognized in our condensed consolidated statements of operations for the three and six months ended June 30, 2023 and 2022 is based on awards ultimately expected to vest, it has been reduced for estimated forfeitures, but at a minimum, reflects the grant-date fair value of those awards that actually vested in the period. Forfeitures have been estimated at the time of grant based on historical data and revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates. We have not recognized any stock-based compensation expense for performance-based stock options on our condensed consolidated statements of operations for the three and six months ended June 30, 2023 and 2022, as achievement of the specified strategic milestones was not considered probable at that time.

Stock Options

We grant service-based and performance-based stock options under our equity plans to employees, non-employee directors and consultants. The service-based vesting period for employee stock options is generally four years from the date of the stock option grant. Performance-based stock options vest upon the achievement of specified strategic milestones. The fair value of service-based stock options granted during the six months ended June 30, 2023 and 2022 has been estimated at the date of grant using the Black Scholes option-pricing model with the following assumptions:


	Six Months Ended June 30,
	2023	2022
Dividend yield	0%	0%
Expected volatility range	81.5% to 81.9%	77.7% to 79.9%
Risk-free interest rate range	3.4% to 4.1%	1.7% to 3.4%
Expected term	6 years	5.5 years

Employee Stock Purchase Plan

The fair value of employees’ stock purchase rights during the six months ended June 30, 2023 and 2022 has been estimated using the Black Scholes option-pricing model with the following assumptions:


	Six Months Ended June 30,
	2023	2022
Dividend yield	0%	0%
Expected volatility range	61.0% to 81.1%	50.9% to 61.4%
Risk-free interest rate range	0.1% to 4.8%	0.1% to 0.4%
Expected term range	6 months to 12 months	6 months to 12 months

Dividend yield is based on historical cash dividend payments and Geron has paid no cash dividends to date. The expected volatility range is based on historical volatilities of our stock, since traded options on Geron common stock do not correspond to option terms and the trading volume of options is limited. The risk-free interest rate range is based on the U.S. Zero Coupon Treasury Strip Yields for the expected term in effect on the date of grant for an award. The expected term of stock options is derived from actual historical exercise and post-vesting cancellation data and represents the period of time that stock options granted are expected to be outstanding. The expected term of employees’ stock purchase rights is equal to the purchase period.

Non-Employee Stock-Based Awards

We measure share-based payments to non-employees based on the grant-date fair value of the equity awards. We recognize stock-based compensation expense for the fair value of the vested portion of non-employee stock-based awards on our condensed consolidated statements of operations.

Segment Information

Our executive management team represents our chief decision maker. We view our operations as a single segment, the development of therapeutic products for oncology. As a result, the financial information disclosed herein materially represents all of the financial information related to our principal operating segment.

Recent Accounting Pronouncements

New Accounting Pronouncements – Recently Adopted

In June 2016, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update, or ASU, 2016-13, Measurement of Credit Losses on Financial Instruments, or ASU 2016-13. Subsequent to issuing ASU 2016-13, the FASB issued ASU 2018-19, Codification Improvements to Topic 326, Financial Instruments – Credit Losses, or ASU 2018-19, for the purpose of clarifying certain aspects of ASU 2016-13. In May 2019, the FASB issued ASU 2019-05, Financial Instruments – Credit Losses (Topic 326): Targeted Transition Relief, or ASU 2019-05, to provide entities with more flexibility in applying the fair value option on adoption of the credit impairment standard. In November 2019, the FASB issued ASU 2019-11, Codification Improvements to Topic 326, Financial Instruments – Credit Losses, or ASU 2019-11, which expands the scope of the practical expedient that allows entities to exclude the accrued interest component of amortized cost from various disclosure. We adopted ASU 2016-13 and related updates as of January 1, 2023. Adoption of this new guidance did not have a material impact on our condensed consolidated financial statements.

New Accounting Pronouncements – Issued But Not Yet Adopted

In August 2020, the FASB issued ASU 2020-06, Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity, or ASU 2020-06. The key elements of ASU 2020-06 aim to reduce unnecessary complexity in GAAP for certain financial instruments with characteristics of liabilities and equity. In addressing the complexity, the FASB focused on amending the guidance on convertible instruments and the guidance on the derivatives scope exception for contracts in an entity’s own equity. For convertible instruments, the FASB decided to reduce the number of accounting models for convertible debt instruments and convertible preferred stock. For contracts in an entity’s own equity, the FASB observed that the application of the derivatives scope exception guidance results in accounting for some contracts as derivatives while accounting for economically similar contracts as equity. The FASB also decided to improve and amend the related earnings per share guidance. ASU 2020-06 is effective for fiscal years beginning after December 15, 2021, and interim periods within those fiscal years for public business entities that are not smaller reporting companies. For all other entities, ASU 2020-06 is effective for fiscal years beginning after December 15, 2023, and interim periods within those fiscal years. We plan to adopt ASU 2020-06 as of January 1, 2024. We do not expect the adoption of this standard to have a material impact on our condensed consolidated financial statements.

Other recent accounting pronouncements issued by the FASB did not or are not believed by management to have a material impact on our condensed consolidated financial statements.

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Cash flows from operating activities:
Net loss	$ (87,349)	$ (58,215)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	220	129
Accretion and amortization on investments, net	(4,963)	304
Amortization of debt issuance costs/debt discounts	487	704
Stock-based compensation for services by non-employees	211	28
Stock-based compensation for employees and directors	6,906	3,750
Amortization of right-of-use assets	306	285
Changes in assets and liabilities:
Current and noncurrent assets	2,411	(5,507)
Current and noncurrent liabilities	5,805	(4,094)
Net cash used in operating activities	(75,966)	(62,616)
Cash flows from investing activities:
Purchases of property and equipment	(574)	(120)
Purchases of marketable securities	(355,718)	(57,049)
Proceeds from maturities of marketable securities	133,115	90,406
Net cash (used in) provided by investing activities	(223,177)	33,237
Cash flows from financing activities:
Proceeds from issuances of common stock from equity plans	8,448	761
Proceeds from issuance of common stock from public offering and pre-funded warrant, net of paid issuance costs	213,337	69,916
Proceeds from exercise of warrants	77,602
Debt discount and issuance costs for debt financing		(114)
Net cash provided by financing activities	299,387	70,563
Effect of exchange rates on cash, cash equivalents and restricted cash	(15)	2
Net increase in cash, cash equivalents and restricted cash	229	41,186
Cash, cash equivalents and restricted cash at the beginning of the period	57,209	35,235
Cash, cash equivalents and restricted cash at the end of the period	$ 57,438	$ 76,421

STOCKHOLDERS' EQUITY - PUBLIC OFFERING (Details) - 2023 Public Offering	Jan. 10, 2023 USD ($) $ / shares shares
Public Offering [Line Items]
Issuance of common stock in connection with public offering (in shares) \| shares	68,007,741
Net cash proceeds from public offering after deducting underwriting discount and other offering expenses \| $	$ 213,337,000
Common Stock
Public Offering [Line Items]
Public offering price of common stock per share	$ 2.45
2023 Pre-funded Warrant
Public Offering [Line Items]
Public offering price per share	2.449
Warrant exercise price	$ 0.001

FAIR VALUE MEASUREMENTS (Tables)

6 Months Ended

Jun. 30, 2023

Fair Value Disclosures [Abstract]

Schedule of cash equivalents, restricted cash and marketable securities by security type

Cash equivalents, restricted cash and marketable securities by security type at June 30, 2023 were as follows:


			Gross		Gross
	Amortized		Unrealized		Unrealized			Estimated
(In thousands)	Cost		Gains		Losses			Fair Value
Included in cash and cash equivalents:
Money market funds	$	34,417	$	—	$	—		$	34,417
	$	34,417	$	—	$	—		$	34,417

Restricted cash:
Money market fund	$	263	$	—	$	—		$	263
Certificate of deposit		272		—		—			272
	$	535	$	—	$	—		$	535

Marketable securities:
Government-sponsored enterprise securities (due in less than one year)	$	78,280	$	20	$	(224	)	$	78,076
Government-sponsored enterprise securities (due in one to two years)		18,680		—		(141	)		18,539
Commercial paper (due in less than one year)		202,540		7		(365	)		202,182
Corporate notes (due in less than one year)		34,354		1		(138	)		34,217
Corporate notes (due in one to two years)		9,854		—		(112	)		9,742
	$	343,708	$	28	$	(980	)	$	342,756

Cash equivalents, restricted cash and marketable securities by security type at December 31, 2022 were as follows:


			Gross		Gross
	Amortized		Unrealized		Unrealized			Estimated
(In thousands)	Cost		Gains		Losses			Fair Value
Included in cash and cash equivalents:
Money market funds	$	39,771	$	—	$	—		$	39,771
	$	39,771	$	—	$	—		$	39,771

Restricted cash:
Money market fund	$	93	$	—	$	—		$	93
Certificate of deposit		271		—		—			271
	$	364	$	—	$	—		$	364

Marketable securities:
U.S. Treasury securities (due in less than one year)	$	12,983	$	—	$	(62	)	$	12,921
Municipal securities (due in less than one year)		3,000		—		(24	)		2,976
Government-sponsored enterprise securities (due in less than one year)		9,860		—		(14	)		9,846
Commercial paper (due in less than one year)		64,285		6		(92	)		64,199
Corporate notes (due in less than one year)		26,014		—		(55	)		25,959
	$	116,142	$	6	$	(247	)	$	115,901

Schedule of cash equivalents and marketable securities with unrealized losses

Cash equivalents and marketable securities with unrealized losses that have been in a continuous unrealized loss position for less than 12 months and 12 months or longer at June 30, 2023 and December 31, 2022 were as follows:


	Less Than 12 Months					12 Months or Longer					Total
			Gross					Gross					Gross
	Estimated		Unrealized			Estimated		Unrealized			Estimated		Unrealized
(In thousands)	Fair Value		Losses			Fair Value		Losses			Fair Value		Losses
As of June 30, 2023:
Government-sponsored enterprise securities (due in less than one year)	$	58,651	$	(224	)	$	—	$	—		$	58,651	$	(224	)
Government-sponsored enterprise securities (due in one to two years)		18,538		(141	)		—		—			18,538		(141	)
Commercial paper (due in less than one year)		169,851		(365	)		—		—			169,851		(365	)
Corporate notes (due in less than one year)		29,211		(138	)		—		—			29,211		(138	)
Corporate notes (due in one to two years)		8,746		(112	)		—		—			8,746		(112	)
	$	284,997	$	(980	)	$	—	$	—		$	284,997	$	(980	)

As of December 31, 2022:
U.S. Treasury securities (due in less than one year)	$	11,424	$	(57	)	$	1,497	$	(5	)	$	12,921	$	(62	)
Municipal securities (due in less than a year)		—		—			2,976		(24	)		2,976		(24	)
Government-sponsored enterprise securities (due in less than one year)		9,845		(14	)		—		—			9,845		(14	)
Commercial paper (due in less than one year)		52,454		(92	)		—		—			52,454		(92	)
Corporate notes (due in less than one year)		1,998		(2	)		23,962		(53	)		25,960		(55	)
	$	75,721	$	(165	)	$	28,435	$	(82	)	$	104,156	$	(247	)

Schedule of financial instruments measured at fair value on recurring basis

The following table presents information about our financial instruments that are measured at fair value on a recurring basis as of June 30, 2023 and December 31, 2022 and indicates the fair value category assigned.


	Fair Value Measurements at Reporting Date Using
	Quoted Prices in				Significant
	Active Markets for		Significant Other		Unobservable
	Identical Assets		Observable Inputs		Inputs
(In thousands)	Level 1		Level 2		Level 3		Total
As of June 30, 2023:
Money market funds(1)(2)	$	34,680	$	—	$	—	$	34,680
Certificate of deposit(2)		272		—		—		272
Government-sponsored enterprise securities(3)(4)		—		96,615		—		96,615
Commercial paper(3)		—		202,182		—		202,182
Corporate notes(3)(4)		—		43,959		—		43,959
Total	$	34,952	$	342,756	$	—	$	377,708
As of December 31, 2022:
Money market funds(1)(2)	$	39,864	$	—	$	—	$	39,864
Certificate of deposit(2)		271		—		—		271
U.S. Treasury securities(3)		—		12,921		—		12,921
Municipal securities(3)		—		2,976		—		2,976
Government-sponsored enterprise securities(2)		—		9,846		—		9,846
Commercial paper(3)		—		64,199		—		64,199
Corporate notes(3)		—		25,959		—		25,959
Total	$	40,135	$	115,901	$	—	$	156,036

(1)

Included in cash and cash equivalents on our condensed consolidated balance sheets.

(2)

Included in restricted cash on our condensed consolidated balance sheets.

(3)

Included in current portion of marketable securities on our condensed consolidated balance sheets.

(4)

Included in noncurrent portion of marketable securities on our condensed consolidated balance sheets.

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - STOCK BASED COMPENSATION (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Stock-Based Compensation Expense
Stock-based compensation expense included in operating expenses	$ 3,945	$ 2,058	$ 6,906	$ 3,750
Research and development
Stock-Based Compensation Expense
Stock-based compensation expense included in operating expenses	1,590	1,012	2,896	1,867
General and administrative
Stock-Based Compensation Expense
Stock-based compensation expense included in operating expenses	$ 2,355	$ 1,046	$ 4,010	$ 1,883

DEBT

6 Months Ended

Jun. 30, 2023

Debt Disclosure [Abstract]

DEBT

4. DEBT

On September 30, 2020, we, Hercules Capital, Inc., or Hercules, and Silicon Valley Bank, a Division of First-Citizens Bank & Trust Company (successor by purchase to the Federal Deposit Insurance Corporation as receiver for Silicon Valley Bridge Bank, N.A. (as successor to Silicon Valley Bank)), or SVB, entered into a term loan facility, or the Original Loan Agreement, consisting of up to $75,000,000 aggregate principal amount available to us, as amended in August 2021. On June 30, 2022, or the Effective Date, we entered into a second amendment to the Original Loan Agreement, or as amended, the Loan Agreement. Under the second amendment, the aggregate principal amount available to us increased from $75,000,000 to $125,000,000, with such principal being available in a series of tranches, subject to certain terms and conditions.

As of June 30, 2023, a total of $50,000,000 has been drawn under the Loan Agreement. As of June 30, 2023, $55,000,000 remains as committed principal that can be drawn as follows: (a) one tranche of $10,000,000 is available from January 1, 2023 until December 15, 2023, subject to the achievement of certain clinical and regulatory milestones, and satisfaction of certain other requirements; (b) a second tranche of $20,000,000 is available from September 15, 2023 until September 15, 2024, subject to the achievement of certain clinical and regulatory milestones, and satisfaction of certain capitalization requirements; and (c) a final tranche of $25,000,000 is available through December 31, 2024, subject to approval by an investment committee comprised of Hercules and SVB. With the exception of the final tranche, and subject to achievement of the applicable milestones and other requirements with respect to each tranche, draw downs are at our election.

Under the Loan Agreement, if we choose to prepay the principal with respect to any future draw down after the Effective Date, any such prepayment within the first 36 months after the Effective Date will be subject to a prepayment charge equal to 1.5% of the principal amount prepaid. No prepayment charge will be assessed for any prepayment occurring more than 36 months after the Effective Date.

Under the Loan Agreement, the maturity date, interest only payment dates, end of term charges, collateral, events of default, representations, warranties and covenants remain consistent with the terms of the Original Loan Agreement, except as follows:

•

Beginning June 1, 2022 and prior to the regulatory approval for imetelstat, or the potential Regulatory Approval, if any, we are required to maintain a minimum cash balance in an amount equal to the greater of: 50% of the outstanding principal amount under the Loan Agreement or $30,000,000.

•

After the potential Regulatory Approval, if any, the minimum cash requirement may be satisfied through one of the following three options, as elected by us: (a) maintaining a cash balance in an amount not less than 40% of the outstanding principal amount under the Loan Agreement; (b) maintaining a cash balance in an amount not less than 25% of the outstanding principal amount under the Loan Agreement, if our market cap is or exceeds $750,000,000; or (c) maintaining six month net product revenues of at least 70% of net product revenues forecasted by us, should any potential Regulatory Approval for imetelstat be obtained.

We are in compliance with the covenants under the Loan Agreement as of June 30, 2023. The interest-only payment period was extended from April 2023 to April 2024 upon the achievement of positive top-line results from the IMerge Phase 3 clinical trial in January 2023.

As of June 30, 2023, the net carrying value of the debt under the Loan Agreement was $51,644,000, which includes the principal amount of $50,000,000 less net unamortized debt discounts and issuance costs of $483,000 plus accrued end of term charge of $2,127,800. The carrying value of the debt approximates the fair value as of June 30, 2023. The debt discounts and debt issuance costs are being amortized to interest expense over the life of the outstanding loan amounts using the effective interest rate method.

The following table presents future minimum payments, including interest and the end of term charge, under the Loan Agreement as of June 30, 2023 (in thousands):


Remainder of 2023	$	3,558
2024		39,277
2025		20,031
Total		62,866
Less: amount representing interest		(9,592	)
Less: unamortized debt discount and issuance costs		(483	)
Less: unaccrued end of term charge		(1,147	)
Less: current portion of debt		(10,842	)
Noncurrent portion of debt	$	40,802

- Definition

The entire disclosure for information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, own-share lending arrangements and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1B

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(c))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 470
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org//470/tableOfContent

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1B

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1B

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (i)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1B

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1C
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1C

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1C
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1C

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1C
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1C

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1E
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1E

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1I
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1I

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1I
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1I

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1I
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1I

+ Details

ACCRUED LIABILITIES

6 Months Ended

Jun. 30, 2023

Payables and Accruals [Abstract]

ACCRUED LIABILITIES

3. ACCRUED LIABILITIES

Accrued liabilities consisted of the following as of June 30, 2023 and December 31, 2022:


	JUNE 30,		DECEMBER 31,
(In thousands)	2023		2022
CRO and clinical trial costs	$	22,776	$	17,040
Manufacturing activities		11,798		5,321
Legal settlements		7,000		8,350
Professional legal and accounting fees		857		1,318
Interest payable		584		561
Other		2,021		510
	$	45,036	$	33,100

DEBT - Future Minimum Payments Under Loan Agreement (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Debt Disclosure [Abstract]
Remainder of 2023	$ 3,558
2024	39,277
2025	20,031
Total	62,866
Less: amount representing interest	(9,592)
Less: unamortized debt discounts and issuance costs	(483)
Less: unaccrued end of term charge	(1,147)
Less: current portion of debt	(10,842)
Noncurrent portion of debt	$ 40,802	$ 30,212

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

6 Months Ended

Jun. 30, 2023

Accounting Policies [Abstract]

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

1. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Basis of Presentation

Prior Period Reclassification

Principles of Consolidation

Net Loss Per Share

Use of Estimates

Fair Value of Financial Instruments

Cash Equivalents and Marketable Securities

Leases

Debt Issuance Costs and Debt Discounts

Revenue Recognition

reasonable estimate can be made. Revenue is then recognized over the remaining estimated period of performance using the cumulative catch-up method.

License Agreements

Restricted Cash

Restricted cash consists of funds maintained in separate money market or certificate of deposit accounts for credit card purchases.

Research and Development Expenses

Depreciation and Amortization

Stock-Based Compensation


	Three Months Ended June 30,				Six Months Ended June 30,
(In thousands)	2023		2022		2023		2022
Research and development	$	1,590	$	1,012	$	2,896	$	1,867
General and administrative	$	2,355		1,046	$	4,010		1,883
Stock-based compensation expense included in operating expenses	$	3,945	$	2,058	$	6,906	$	3,750

Stock Options


	Six Months Ended June 30,
	2023	2022
Dividend yield	0%	0%
Expected volatility range	81.5% to 81.9%	77.7% to 79.9%
Risk-free interest rate range	3.4% to 4.1%	1.7% to 3.4%
Expected term	6 years	5.5 years

Employee Stock Purchase Plan

The fair value of employees’ stock purchase rights during the six months ended June 30, 2023 and 2022 has been estimated using the Black Scholes option-pricing model with the following assumptions:


	Six Months Ended June 30,
	2023	2022
Dividend yield	0%	0%
Expected volatility range	61.0% to 81.1%	50.9% to 61.4%
Risk-free interest rate range	0.1% to 4.8%	0.1% to 0.4%
Expected term range	6 months to 12 months	6 months to 12 months

Non-Employee Stock-Based Awards

Segment Information

Recent Accounting Pronouncements

New Accounting Pronouncements – Recently Adopted

New Accounting Pronouncements – Issued But Not Yet Adopted

Other recent accounting pronouncements issued by the FASB did not or are not believed by management to have a material impact on our condensed consolidated financial statements.

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Jun. 30, 2022
Public Offering of Common Stock and Warrants
Issuance costs	$ 14,507	$ 5,066

DEBT (Tables)

6 Months Ended

Jun. 30, 2023

Debt Disclosure [Abstract]

Future Minimum Payments Under Loan Agreement

The following table presents future minimum payments, including interest and the end of term charge, under the Loan Agreement as of June 30, 2023 (in thousands):


Remainder of 2023	$	3,558
2024		39,277
2025		20,031
Total		62,866
Less: amount representing interest		(9,592	)
Less: unamortized debt discount and issuance costs		(483	)
Less: unaccrued end of term charge		(1,147	)
Less: current portion of debt		(10,842	)
Noncurrent portion of debt	$	40,802

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - STOCK OPTIONS AND EMPLOYEE STOCK PURCHASE PLAN (Details)	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Stock Options
Stock-Based Compensation
Vesting period of awards	4 years
Assumptions used to estimate fair value of awards
Dividend yield (as a percent)	0.00%	0.00%
Expected volatility range, minimum (as a percent)	81.50%	77.70%
Expected volatility range, maximum (as a percent)	81.90%	79.90%
Risk-free interest rate range, minimum (as a percent)	3.40%	1.70%
Risk-free interest rate range, maximum (as a percent)	4.10%	3.40%
Expected term	6 years	5 years 6 months
Employee Stock Purchase Plan
Assumptions used to estimate fair value of awards
Dividend yield (as a percent)	0.00%	0.00%
Expected volatility range, minimum (as a percent)	61.00%	50.90%
Expected volatility range, maximum (as a percent)	81.10%	61.40%
Risk-free interest rate range, minimum (as a percent)	0.10%	0.10%
Risk-free interest rate range, maximum (as a percent)	4.80%	0.40%
Employee Stock Purchase Plan \| Minimum
Assumptions used to estimate fair value of awards
Expected term	6 months	6 months
Employee Stock Purchase Plan \| Maximum
Assumptions used to estimate fair value of awards
Expected term	12 months	12 months

CONTINGENCIES AND UNCERTAINTIES

6 Months Ended

Jun. 30, 2023

Commitments and Contingencies Disclosure [Abstract]

CONTINGENCIES AND UNCERTAINTIES

5. CONTINGENCIES AND UNCERTAINTIES

Purported Securities Lawsuits

Between January 23, 2020 and March 5, 2020, three securities class action lawsuits were filed against us and certain of our officers. One of the lawsuits was voluntarily dismissed on March 19, 2020. The other two lawsuits, filed in the U.S. District Court, or the Court, for the Northern District of California, or the Northern District, were consolidated by the Court on May 14, 2020, and on August 20, 2020, the lead plaintiffs filed a consolidated class action complaint. The consolidated class action complaint alleges violations of the Securities Exchange Act of 1934, as amended, or the Exchange Act, in connection with allegedly false and misleading statements made by us related to IMbark during the period from March 19, 2018, to September 26, 2018. The consolidated class action complaint alleges, among other things, that we violated Sections 10(b) and 20(a) of the Exchange Act and SEC Rule 10b-5 by failing to disclose facts related to the alleged failure of IMbark to meet the two primary endpoints of the trial, spleen response rate and Total Symptom Score, and that our stock price dropped when such information was disclosed. The plaintiffs in the consolidated class action complaint seek damages and interest, and an award of reasonable costs, including attorneys’ fees. On October 22, 2020, lead plaintiffs filed an amended consolidated class action complaint. We filed a motion to dismiss the amended consolidated class action complaint on November 23, 2020. On April 12, 2021, the Court granted in part and denied in part our motion to dismiss. Our answer to the amended consolidated class action complaint was filed on May 13, 2021. On September 30, 2021, lead plaintiffs filed their motion for class certification, and on April 2, 2022, the Court granted the lead plaintiffs’ motion for class certification. On September 2, 2022, the parties agreed to a settlement and entered into a Stipulation and Agreement of Settlement, or the Stipulation, which is subject to Court approval. On October 13, 2022, the Court preliminarily approved the parties’ settlement, and permitted notice to be distributed to the class members. On March 30, 2023, the Court held a hearing on the motion for final approval of settlement and plan of allocation and ordered supplemental notice be sent to all of the class members. A second final approval hearing is scheduled for August 24, 2023. Final approval of the settlement by the Court is subject to a number of conditions and contingencies out of our control. There can be no guarantee that all of these conditions and contingencies will occur. Should a material condition or contingency to the settlement fail to occur, one or both of the parties to the settlement may exercise their right to terminate the settlement agreement.

Under the terms of the Stipulation, in exchange for the release and dismissal with prejudice of all claims against the defendants in the consolidated class action complaint, we agreed to pay and/or to cause our insurance carriers to pay a total of $24,000,000, comprised of $17,000,000 in cash, which was paid into an escrow account under our available insurance coverage and, at our election, $7,000,000 in either shares of our common stock and/or cash which is payable after final approval of the settlement by the Court. The proposed settlement does not constitute an admission of fault or wrongdoing by Geron or our Chief Executive Officer. The proposed settlement remains subject to final approval by the Court and certain other conditions. As of June 30, 2023 and December 31, 2022, our portion of the settlement amount of $7,000,000 has been included in accrued liabilities on our condensed consolidated balance sheets.

Between April 23, 2020 and June 8, 2021, seven shareholder derivative actions were filed, naming as defendants certain of our current officers and certain current and former members of our board. Of these actions, or the Derivative Lawsuits, two were filed in the Northern District, two were filed in the Court of Chancery of the State of Delaware, or the Chancery Court, two were filed in the U.S. District Court for the District of Delaware, or the District of Delaware, and one was filed in the Superior Court of California for the County of San Mateo, or the San Mateo Superior Court, respectively. The plaintiffs in the Derivative Lawsuits allege breach of fiduciary duty and/or violations of Section 14 of the Exchange Act, based on the same underlying facts as the consolidated class action lawsuit described above. The plaintiffs seek damages, corporate governance reforms, equitable relief, restitution, and an award of reasonable costs, including attorneys’ fees. The status of the seven Derivative Lawsuits is currently as follows:

•

On July 2, 2021, we filed a motion to dismiss the consolidated shareholder derivative actions filed in the Chancery Court, or the Chancery Court Derivative Lawsuits. On September 1, 2021, the plaintiffs filed a consolidated amended complaint in the Chancery Court Derivative Lawsuits. On October 12, 2021, we filed our motion to dismiss the consolidated amended complaint. The Chancery Court heard oral argument on the motion on February 15, 2022, and, on June 22, 2022, issued an order staying its decision on our motion to dismiss until after final resolution of the consolidated class action lawsuit described above. On December 21, 2022, the parties in the Chancery Court Derivative Lawsuits entered into a Stipulation of Settlement, or the Derivative Stipulation, that, subject to final approval by the Chancery Court, will resolve the Chancery Court Derivative Lawsuits. On May 17, 2023, following a hearing, the Chancery Court entered an order approving the Derivative Stipulation and dismissing the Chancery Court Derivative Lawsuits with prejudice;

•

The consolidated shareholder derivative actions filed in the District of Delaware have been stayed pending the ruling on our motion to dismiss the Chancery Court Derivative Lawsuits. On December 21, 2022, the parties in the consolidated District of Delaware derivative actions entered into the Derivative Stipulation, that, subject to final approval by the Chancery Court, will resolve the consolidated District of Delaware derivative actions. On May 30, 2023, the parties in the consolidated District of Delaware derivative actions, pursuant to the Derivative Stipulation, sought dismissal of the consolidated District of Delaware derivative actions with prejudice, which the Court granted on May 31, 2023;

•

The consolidated shareholder derivative actions filed in the Northern District were initially stayed through the ruling on our motion to dismiss in the consolidated securities class action lawsuit described above and then subsequently were stayed through the ruling on the lead plaintiffs’ motion for class certification in the consolidated securities class action lawsuit. Subsequent to the grant of class certification in the consolidated securities class action lawsuit, on May 3, 2022, the Northern District entered an order providing plaintiffs until June 7, 2022, to file an amended complaint. On June 7, 2022, plaintiffs filed an amended shareholder derivative complaint. On July 6, 2022, the Northern District entered an order staying the consolidated shareholder derivative actions filed in the Northern District until the earlier of either a public announcement of a settlement in the consolidated securities class action lawsuit or a final, non-appealable judgment in the consolidated securities class action lawsuit. On December 21, 2022, the parties in the consolidated derivative actions in the Northern District entered into the Derivative Stipulation, that, subject to final approval by the Chancery Court will resolve the consolidated derivative actions in the Northern District. On May 30, 2023, the parties in the consolidated derivative actions in the Northern District, pursuant to the Derivative Stipulation, sought dismissal of the consolidated derivative actions in the Northern District with prejudice, which the Court granted the same day; and

•

Our motion to dismiss the shareholder derivative action pursuant to the forum selection clause in our amended and restated bylaws was filed in the San Mateo Superior Court on August 5, 2021. At the hearing on the motion to dismiss on November 2, 2021, the court granted our motion to dismiss and stayed the case until April 19, 2022. At the case management conference on April 19, 2022, the court continued the stay until June 14, 2022. At the case management conference on June 14, 2022, the court continued the stay until December 13, 2022. On December 13, 2022, the court dismissed the action without prejudice.

Under the terms of the Derivative Stipulation, in exchange for the release and dismissal with prejudice of all claims against the defendants in the consolidated shareholder derivative actions filed in the Northern District, the District of Delaware, and the Chancery Court, the parties agreed to a cash settlement of $1,350,000 which was accrued on our consolidated balance sheet as of December 31, 2022. In the second quarter of 2023, our insurance carriers paid $525,000 in cash, and we paid $825,000 in cash, for an aggregate total payment of $1,350,000. The settlement does not constitute an admission of fault or wrongdoing by our current officers or current and former members of our board.

The pending lawsuits and any other related lawsuits are subject to inherent uncertainties, and the actual defense and disposition costs will depend upon many unknown factors. The outcome of the pending lawsuits and any other related lawsuits is necessarily uncertain. We could be forced to expend significant resources in the defense against the pending lawsuits and any other related lawsuits, and we may not prevail. In addition, we have and may continue to incur substantial legal fees and costs in connection with such lawsuits. We currently are not able to estimate the possible additional costs to us, if any, from these matters, and we cannot be certain how long it may take to resolve the pending lawsuits or the possible amount of any damages or legal costs that we may be required to pay. Such amounts could be material to our condensed consolidated financial statements if we do not prevail in the defense against the pending lawsuits and any other related lawsuits, or even if we do prevail. We have not established any reserve for any potential liability relating to the pending lawsuits and any other related lawsuits, other than settlement amounts under the Stipulation. It is possible that we could, in the future, incur judgments or enter into settlements of claims for monetary damages.

Indemnifications to Officers and Directors

Our corporate bylaws require that we indemnify our directors, as well as those who act as directors and officers of other entities at our request, against expenses, judgments, fines, settlements and other amounts actually and reasonably incurred in connection with any proceedings arising out of their services to Geron. In addition, we have entered into separate indemnification agreements with each of our directors and officers which provide for indemnification of these directors and officers under similar circumstances and under additional circumstances. The indemnification obligations are more fully described in our bylaws and the indemnification agreements. We purchase standard insurance to cover claims or a portion of the claims made against our directors and officers. Since a maximum obligation is not explicitly stated in our bylaws or in our indemnification agreements and will depend on the facts and circumstances that arise out of any future claims, the overall maximum amount of the obligations cannot be reasonably estimated.

Severance Plan

We have an Amended and Restated Severance Plan, or Severance Plan, that applies to all employees that are (i) above the Vice President level, (ii) hired by the Company before January 1, 2022, or (iii) not subject to performance improvement plans, and provides

for, among other benefits: (x) a severance payment upon a Change of Control Triggering Event and Separation from Service and (y) a severance payment for each non‑executive employee upon a Non‑Change of Control Triggering Event and Separation from Service. As defined in the Severance Plan, a Change of Control Triggering Event and Separation from Service requires a “double trigger” where: (i) an employee is terminated by us without cause in connection with a change of control or within 12 months following a change of control provided, however, that if an employee is terminated by us in connection with a change of control but immediately accepts employment with our successor or acquirer, the employee will not be eligible for the benefits outlined in the Severance Plan, (ii) an employee resigns because in connection with a change of control, the offered terms of employment (new or continuing) by us or our successor or acquirer within 30 days after the change of control results in a material change in the terms of employment, or (iii) after accepting (or continuing) employment with us after a change of control, an employee resigns within 12 months following a change of control due to a material change in the terms of employment. Under the Severance Plan, a Non‑Change of Control Triggering Event and Separation from Service is defined as an event where a non‑executive employee is terminated by us without cause. Severance payments range from three to 18 months of base salary, depending on the employee’s position with us, payable in a lump sum payment. The Severance Plan also provides that the provisions of employment agreements entered into between us and executive or non‑executive employees supersede the provisions of the Severance Plan. As of June 30, 2023, all our executive officers have employment agreements with provisions that may provide greater severance benefits than those in the Severance Plan.

Risks Related to Global Economic, Political and Health Conditions

Our business is subject to various risks and uncertainties, including risks and uncertainties associated with macroeconomic or other global economic conditions, including those resulting from inflation, rising interest rates, prospects of a recession, bank failures and other disruptions to financial systems, civil or political unrest, military conflicts, pandemics or other health crises and supply chain and resource issues. Occurrences of such events have caused and may cause in the future and unpredictable impacts on global societies, economies, financial markets and business practices. Specifically for our business, such risks and uncertainties have adversely affected and may continue to adversely affect our ability to:

•

continue to develop imetelstat or advance imetelstat to subsequent clinical trials, including receiving regulatory approval for or to commercialize imetelstat, on a timely basis or at all;

•

conduct and complete current imetelstat clinical trials on a timely basis or at all;

•

establish sales, marketing and distribution capabilities, or obtain coverage and adequate third-party payor reimbursement, to successfully commercialize imetelstat, if regulatory approval is obtained;

•

open clinical sites or recruit, enroll and retain patients in current or future clinical trials of imetelstat;

•

manufacture and supply imetelstat in adequate quantities that meet specifications that may be approved or required by regulatory authorities and on timelines necessary for current and potential future clinical trials and potential commercial uses;

•

execute on our business strategy and/or our operations by our employees without any restrictions; and

•

obtain additional capital to continue the development of imetelstat in current and any potential future clinical trials of imetelstat, and establish potential future imetelstat commercialization efforts.

The extent to which macroeconomic or other global economic conditions, including those resulting from inflation, rising interest rates, prospects of a recession, bank failures and other disruptions to financial systems, civil or political unrest, military conflicts, pandemics or other health crises and supply chain and resource issues, ultimately impact our business, our regulatory and clinical development activities, clinical supply chain and other business operations, as well as the value of and market for our common stock, will depend on future developments that are highly uncertain and cannot be predicted with confidence. Accordingly, we do not yet know the full extent of potential delays or impacts on our business, our regulatory and clinical development activities, clinical supply chain and other business operations or the global economy as a whole. However, these effects could materially and adversely affect our business and business prospects, our financial condition and the future of imetelstat.

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Statement of Comprehensive Income [Abstract]
Net loss	$ (49,227)	$ (28,117)	$ (87,349)	$ (58,215)
Net unrealized loss on marketable securities	(786)	(82)	(711)	(621)
Foreign currency translation adjustments	1	11	(15)	12
Comprehensive loss	$ (50,012)	$ (28,188)	$ (88,075)	$ (58,824)

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(g)(1)(ii))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 323
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481687/323-10-50-3

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
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+ Details

FAIR VALUE MEASUREMENTS - SECURITY TYPE (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Included in cash and cash equivalents:
Amortized Cost	$ 34,417	$ 39,771
Estimated Fair Value	34,417	39,771
Restricted cash:
Amortized Cost	535	364
Estimated Fair Value	535	364
Marketable securities:
Amortized Cost	343,708	116,142
Gross Unrealized Gains	28	6
Gross Unrealized Losses	(980)	(247)
Estimated Fair Value	342,756	115,901
Money market funds
Included in cash and cash equivalents:
Amortized Cost	34,417	39,771
Estimated Fair Value	34,417	39,771
Restricted cash:
Amortized Cost	263	93
Estimated Fair Value	263	93
Certificate of deposit
Restricted cash:
Amortized Cost	272	271
Estimated Fair Value	272	271
U.S. Treasury securities (due in less than one year)
Marketable securities:
Amortized Cost		12,983
Gross Unrealized Losses		(62)
Estimated Fair Value		12,921
Municipal securities (due in less than one year)
Marketable securities:
Amortized Cost		3,000
Gross Unrealized Losses		(24)
Estimated Fair Value		2,976
Government-sponsored enterprise securities (due in less than one year)
Marketable securities:
Amortized Cost	78,280	9,860
Gross Unrealized Gains	20
Gross Unrealized Losses	(224)	(14)
Estimated Fair Value	78,076	9,846
Government-sponsored enterprise securities (due in one to two years)
Marketable securities:
Amortized Cost	18,680
Gross Unrealized Losses	(141)
Estimated Fair Value	18,539
Commercial paper (due in less than one year)
Marketable securities:
Amortized Cost	202,540	64,285
Gross Unrealized Gains	7	6
Gross Unrealized Losses	(365)	(92)
Estimated Fair Value	202,182	64,199
Corporate notes (due in less than one year)
Marketable securities:
Amortized Cost	34,354	26,014
Gross Unrealized Gains	1
Gross Unrealized Losses	(138)	(55)
Estimated Fair Value	34,217	$ 25,959
Corporate notes (due in one to two years)
Marketable securities:
Amortized Cost	9,854
Gross Unrealized Losses	(112)
Estimated Fair Value	$ 9,742

CONTINGENCIES AND UNCERTAINTIES - Litigation Settlement (Details) - Insurance Claims - USD ($)			3 Months Ended
	Dec. 21, 2022	Sep. 02, 2022	Jun. 30, 2023	Dec. 31, 2022
Class Action Stipulation
Loss Contingencies [Line Items]
Settlement agreement date		September 2, 2022
Litigation settlement, amount		$ 24,000,000
Litigation settlement amount, Accrued liabilities recognized			$ 7,000,000	$ 7,000,000
Settlement paid in cash by insurers		17,000,000
Settlement to be paid in cash or shares as elected by company		$ 7,000,000
Derivative Stipulation
Loss Contingencies [Line Items]
Settlement agreement date	December 21, 2022
Litigation settlement, amount	$ 1,350,000
Litigation settlement amount, Accrued liabilities recognized				$ 1,350,000
Settlement paid in cash by insurers			525,000
Settlement paid in cash by company			$ 825,000

ACCRUED LIABILITIES (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Payables and Accruals [Abstract]
CRO and clinical trial costs	$ 22,776	$ 17,040
Manufacturing activities	11,798	5,321
Legal settlements	7,000	8,350
Professional legal and accounting fees	857	1,318
Interest payable	584	561
Other	2,021	510
Accrued liabilities	$ 45,036	$ 33,100

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 56,903	$ 56,845
Restricted cash	535	364
Marketable securities	314,475	115,901
Interest and other receivables	1,187	3,144
Prepaid and other current assets	4,179	3,992
Total current assets	377,279	180,246
Noncurrent marketable securities	28,281
Property and equipment, net	1,147	793
Operating leases, right-of-use assets	3,841	4,147
Deposits and other assets	4,748	5,389
Total assets	415,296	190,575
Current liabilities:
Accounts payable	7,673	10,190
Accrued compensation and benefits	8,232	11,534
Operating lease liabilities	786	925
Debt	10,842	20,945
Accrued liabilities	45,036	33,100
Total current liabilities	72,569	76,694
Noncurrent operating lease liabilities	3,498	3,671
Noncurrent debt	40,802	30,212
Commitments and contingencies
Stockholders' equity:
Common stock	522	390
Additional paid-in capital	1,799,841	1,493,469
Accumulated deficit	(1,500,991)	(1,413,642)
Accumulated other comprehensive loss	(945)	(219)
Total stockholders' equity	298,427	79,998
Total liabilities and stockholders' equity	$ 415,296	$ 190,575

STOCKHOLDERS' EQUITY

6 Months Ended

Jun. 30, 2023

Stockholders' Equity Note [Abstract]

STOCKHOLDERS' EQUITY

6. STOCKHOLDERS’ EQUITY

Public Offering

On January 10, 2023 we completed the January 2023 offering consisting of 68,007,741 shares of our common stock and the 2023 pre-funded warrant. All of the securities were issued separately. The public offering price of the common stock was $2.45 per share. The public offering price of the 2023 pre-funded warrant was $2.449 per share. The 2023 pre-funded warrant has an exercise price of $0.001 per share and may be exercised at any time until the 2023 pre-funded warrant is exercised in full. As of June 30, 2023, none of the 2023 pre-funded warrant has been exercised. The net cash proceeds from this offering were $213,337,000, after deducting

the underwriting discount and other offering expenses paid by us, and exclude any future proceeds from the exercise of the 2023 pre-funded warrant.

Upon the issuance of the 2023 pre-funded warrant, we evaluated the terms of each warrant to determine the appropriate accounting and classification pursuant to FASB Accounting Standards Codification Topic 480, Distinguishing Liabilities from Equity, and FASB Accounting Standards Codification Topic 815, Derivatives and Hedging. Warrants are classified as liabilities when the warrant terms allow settlement of the warrant exercise in cash and classified as equity when the warrant terms only allow settlement in shares of common stock. The terms of the 2023 pre-funded warrant include certain provisions related to fundamental transactions and a cashless exercise provision in the event registered shares are not available, and do not include any mandatory redemption provisions. Based on our evaluation, we concluded the 2023 pre-funded warrant should be classified as equity with no subsequent remeasurement as long as such warrant continue to be classified as equity.

Warrant Exercises

In the first quarter of 2023, warrants to purchase 44,983,194 shares of Geron common stock were exercised for net cash proceeds of approximately $59,835,000. In the second quarter of 2023, warrants to purchase 12,842,857 shares of Geron common stock were exercised for net cash proceeds of approximately $17,767,000. The warrants were issued in connection with underwritten public offerings of common stock and pre-funded warrants, together with accompanying stock purchase warrants in May 2020 and April 2022. As of June 30, 2023, the following warrants remained outstanding:

•

pre-funded warrants with an exercise price of $0.001 per share to purchase 51,430,477 shares of our common stock;

•

stock purchase warrants with an exercise price of $1.30 per share to purchase 2,474,503 shares of our common stock related to the public offering of our common stock in May 2020; and

•

stock purchase warrants with an exercise price of $1.45 per share to purchase 19,523,812 shares of our common stock related to the public offering of our common stock in April 2022.

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - ANTI-DILUTIVE SHARES (Details) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Stock options and warrants excluded from diluted net loss per share calculation due to net loss position
Antidilutive Securities Excluded from Computation of Earnings Per Share
Potential dilutive securities excluded from diluted earnings (loss) per share calculation (in shares)	97,584,078	153,703,476	97,584,078	153,703,476

DEBT - Additional Information (Details) - Hercules and Silicon Valley Bank [Member] - USD ($)	Jun. 30, 2022	Jun. 01, 2022	Jun. 30, 2023	Sep. 30, 2020
Debt Instrument [Line Items]
Maximum borrowing capacity under term loan	$ 125,000,000			$ 75,000,000
Principal amount outstanding under term loan			$ 50,000,000
Available remaining loan committed principal			55,000,000
Carrying value of term loan, net			51,644,000
Unamortized debt discount and issuance costs			483,000
Accrued end of term charge			$ 2,127,800
Prepayment charge (as a percentage)	1.50%
Charge for prepayment occurring 36 months after effective date	$ 0
Description of term loan payment terms	Under the Loan Agreement, if we choose to prepay the principal with respect to any future draw down after the Effective Date, any such prepayment within the first 36 months after the Effective Date will be subject to a prepayment charge equal to 1.5% of the principal amount prepaid. No prepayment charge will be assessed for any prepayment occurring more than 36 months after the Effective Date.
Minimum cash balance as a percentage of loan amount outstanding		50.00%
Debt covenant minimum cash balance		$ 30,000,000
Tranche One [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity under term loan	$ 10,000,000
Start date to borrow under a tranche for a debt instrument	Jan. 01, 2023
Expiration date to borrow under a tranche for a debt instrument	Dec. 15, 2023
Tranche Two [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity under term loan	$ 20,000,000
Start date to borrow under a tranche for a debt instrument	Sep. 15, 2023
Expiration date to borrow under a tranche for a debt instrument	Sep. 15, 2024
Tranche Three [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity under term loan	$ 25,000,000
Expiration date to borrow under a tranche for a debt instrument	Dec. 31, 2024
Option One Min Cash Debt Covenant [Member]
Debt Instrument [Line Items]
Minimum cash balance as a percentage of loan amount outstanding	40.00%
Option Two Min Cash Debt Covenant [Member]
Debt Instrument [Line Items]
Minimum cash balance as a percentage of loan amount outstanding	25.00%
Minimum market capitalization requirement for option	$ 750,000,000
Option Three Min Cash Debt Covenant [Member]
Debt Instrument [Line Items]
Minimum cash balance requirement to be met as a percentage of six-month product revenue against forecast	70.00%
Minimum percentage of net product revenues maintenance period	6 months

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)

6 Months Ended

Jun. 30, 2023

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Summary of allocation of stock-based compensation expense included in operating expenses on condensed consolidated statements of operations related to share-based payment awards


	Three Months Ended June 30,				Six Months Ended June 30,
(In thousands)	2023		2022		2023		2022
Research and development	$	1,590	$	1,012	$	2,896	$	1,867
General and administrative	$	2,355		1,046	$	4,010		1,883
Stock-based compensation expense included in operating expenses	$	3,945	$	2,058	$	6,906	$	3,750

Schedule of assumptions used to estimate the fair value of service-based stock options granted

The fair value of service-based stock options granted during the six months ended June 30, 2023 and 2022 has been estimated at the date of grant using the Black Scholes option-pricing model with the following assumptions:


	Six Months Ended June 30,
	2023	2022
Dividend yield	0%	0%
Expected volatility range	81.5% to 81.9%	77.7% to 79.9%
Risk-free interest rate range	3.4% to 4.1%	1.7% to 3.4%
Expected term	6 years	5.5 years

Schedule of assumptions used to estimate the fair value of employee stock purchases under the purchase plan

The fair value of employees’ stock purchase rights during the six months ended June 30, 2023 and 2022 has been estimated using the Black Scholes option-pricing model with the following assumptions:


	Six Months Ended June 30,
	2023	2022
Dividend yield	0%	0%
Expected volatility range	61.0% to 81.1%	50.9% to 61.4%
Risk-free interest rate range	0.1% to 4.8%	0.1% to 0.4%
Expected term range	6 months to 12 months	6 months to 12 months

FAIR VALUE MEASUREMENTS

6 Months Ended

Jun. 30, 2023

Fair Value Disclosures [Abstract]

FAIR VALUE MEASUREMENTS

2. FAIR VALUE MEASUREMENTS

Cash Equivalents and Marketable Securities

Cash equivalents, restricted cash and marketable securities by security type at June 30, 2023 were as follows:


			Gross		Gross
	Amortized		Unrealized		Unrealized			Estimated
(In thousands)	Cost		Gains		Losses			Fair Value
Included in cash and cash equivalents:
Money market funds	$	34,417	$	—	$	—		$	34,417
	$	34,417	$	—	$	—		$	34,417

Restricted cash:
Money market fund	$	263	$	—	$	—		$	263
Certificate of deposit		272		—		—			272
	$	535	$	—	$	—		$	535

Marketable securities:
Government-sponsored enterprise securities (due in less than one year)	$	78,280	$	20	$	(224	)	$	78,076
Government-sponsored enterprise securities (due in one to two years)		18,680		—		(141	)		18,539
Commercial paper (due in less than one year)		202,540		7		(365	)		202,182
Corporate notes (due in less than one year)		34,354		1		(138	)		34,217
Corporate notes (due in one to two years)		9,854		—		(112	)		9,742
	$	343,708	$	28	$	(980	)	$	342,756

Cash equivalents, restricted cash and marketable securities by security type at December 31, 2022 were as follows:


			Gross		Gross
	Amortized		Unrealized		Unrealized			Estimated
(In thousands)	Cost		Gains		Losses			Fair Value
Included in cash and cash equivalents:
Money market funds	$	39,771	$	—	$	—		$	39,771
	$	39,771	$	—	$	—		$	39,771

Restricted cash:
Money market fund	$	93	$	—	$	—		$	93
Certificate of deposit		271		—		—			271
	$	364	$	—	$	—		$	364

Marketable securities:
U.S. Treasury securities (due in less than one year)	$	12,983	$	—	$	(62	)	$	12,921
Municipal securities (due in less than one year)		3,000		—		(24	)		2,976
Government-sponsored enterprise securities (due in less than one year)		9,860		—		(14	)		9,846
Commercial paper (due in less than one year)		64,285		6		(92	)		64,199
Corporate notes (due in less than one year)		26,014		—		(55	)		25,959
	$	116,142	$	6	$	(247	)	$	115,901


	Less Than 12 Months					12 Months or Longer					Total
			Gross					Gross					Gross
	Estimated		Unrealized			Estimated		Unrealized			Estimated		Unrealized
(In thousands)	Fair Value		Losses			Fair Value		Losses			Fair Value		Losses
As of June 30, 2023:
Government-sponsored enterprise securities (due in less than one year)	$	58,651	$	(224	)	$	—	$	—		$	58,651	$	(224	)
Government-sponsored enterprise securities (due in one to two years)		18,538		(141	)		—		—			18,538		(141	)
Commercial paper (due in less than one year)		169,851		(365	)		—		—			169,851		(365	)
Corporate notes (due in less than one year)		29,211		(138	)		—		—			29,211		(138	)
Corporate notes (due in one to two years)		8,746		(112	)		—		—			8,746		(112	)
	$	284,997	$	(980	)	$	—	$	—		$	284,997	$	(980	)

As of December 31, 2022:
U.S. Treasury securities (due in less than one year)	$	11,424	$	(57	)	$	1,497	$	(5	)	$	12,921	$	(62	)
Municipal securities (due in less than a year)		—		—			2,976		(24	)		2,976		(24	)
Government-sponsored enterprise securities (due in less than one year)		9,845		(14	)		—		—			9,845		(14	)
Commercial paper (due in less than one year)		52,454		(92	)		—		—			52,454		(92	)
Corporate notes (due in less than one year)		1,998		(2	)		23,962		(53	)		25,960		(55	)
	$	75,721	$	(165	)	$	28,435	$	(82	)	$	104,156	$	(247	)

The gross unrealized losses related to U.S. Treasury securities, municipal securities, government-sponsored enterprise securities, commercial paper and corporate notes as of June 30, 2023 and December 31, 2022 were due to changes in interest rates and not credit risk. If an available-for-sale security’s fair value is less than its amortized cost basis, we evaluate whether the decline is the result of a credit loss, in which case an impairment is recorded through an allowance for credit losses. We have not recorded any allowances for credit losses on our available-for-sale securities for the three and six months ended June 30, 2023 and 2022 as we have not identified any unrealized losses for these securities attributable to credit factors. Our exposure to unrealized losses may increase in the future due to the economic pressures or uncertainties associated with macroeconomic or other global economic conditions, including those resulting from inflation, rising interest rates, prospects of a recession, bank failures and other disruptions to financial systems, civil or political unrest, military conflicts, pandemics or other health crises.

Fair Value on a Recurring Basis

We categorize financial instruments recorded at fair value on our condensed consolidated balance sheets based upon the level of judgment associated with inputs used to measure their fair value. The categories are as follows:


Level 1	—	Inputs are unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date. An active market for an asset or liability is a market in which transactions for the asset or liability occur with sufficient frequency and volume to provide pricing information on an ongoing basis.
Level 2	—	Inputs (other than quoted market prices included in Level 1) are either directly or indirectly observable for the asset or liability through correlation with market data at the measurement date and for the duration of the instrument’s anticipated life.
Level 3	—	Inputs reflect management’s best estimate of what market participants would use in pricing the asset or liability at the measurement date. Consideration is given to the risk inherent in the valuation technique and the risk inherent in the inputs to the model.

A financial instrument’s categorization within the valuation hierarchy is based upon the lowest level of input that is significant to the fair value measurement. Money market funds are categorized as Level 1 within the fair value hierarchy as their fair values are based on quoted prices available in active markets. U.S. Treasury securities, municipal securities, government-sponsored enterprise securities, commercial paper, and corporate notes are categorized as Level 2 within the fair value hierarchy as their fair values are estimated by using pricing models, quoted prices of securities with similar characteristics or discounted cash flows.


	Fair Value Measurements at Reporting Date Using
	Quoted Prices in				Significant
	Active Markets for		Significant Other		Unobservable
	Identical Assets		Observable Inputs		Inputs
(In thousands)	Level 1		Level 2		Level 3		Total
As of June 30, 2023:
Money market funds(1)(2)	$	34,680	$	—	$	—	$	34,680
Certificate of deposit(2)		272		—		—		272
Government-sponsored enterprise securities(3)(4)		—		96,615		—		96,615
Commercial paper(3)		—		202,182		—		202,182
Corporate notes(3)(4)		—		43,959		—		43,959
Total	$	34,952	$	342,756	$	—	$	377,708
As of December 31, 2022:
Money market funds(1)(2)	$	39,864	$	—	$	—	$	39,864
Certificate of deposit(2)		271		—		—		271
U.S. Treasury securities(3)		—		12,921		—		12,921
Municipal securities(3)		—		2,976		—		2,976
Government-sponsored enterprise securities(2)		—		9,846		—		9,846
Commercial paper(3)		—		64,199		—		64,199
Corporate notes(3)		—		25,959		—		25,959
Total	$	40,135	$	115,901	$	—	$	156,036

(1)

Included in cash and cash equivalents on our condensed consolidated balance sheets.

(2)

Included in restricted cash on our condensed consolidated balance sheets.

(3)

Included in current portion of marketable securities on our condensed consolidated balance sheets.

(4)

Included in noncurrent portion of marketable securities on our condensed consolidated balance sheets.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - USEFUL LIVES OF ASSETS (Details)	Jun. 30, 2023
Depreciation [Abstract]
Estimated useful lives of assets	4 years

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - NET LOSS PER SHARE (Details) - Pre-Funded Warrants	Jun. 30, 2023 $ / shares shares
Warrant exercise price	$ 0.001
Public Offering of Common Stock and Warrants
Warrant to purchase common stock, shares \| shares	51,430,477
Warrant exercise price	$ 0.001

FAIR VALUE MEASUREMENTS - RECURRING BASIS (Details) - Recurring basis - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Fair Value on a Recurring Basis
Total	$ 377,708	$ 156,036
Money market funds
Fair Value on a Recurring Basis
Total	34,680	39,864
Certificate of deposit
Fair Value on a Recurring Basis
Total	272	271
U.S. Treasury securities
Fair Value on a Recurring Basis
Total		12,921
Municipal securities
Fair Value on a Recurring Basis
Total		2,976
Government-sponsored enterprise securities
Fair Value on a Recurring Basis
Total	96,615	9,846
Commercial paper
Fair Value on a Recurring Basis
Total	202,182	64,199
Corporate notes
Fair Value on a Recurring Basis
Total	43,959	25,959
Level 1
Fair Value on a Recurring Basis
Total	34,952	40,135
Level 1 \| Money market funds
Fair Value on a Recurring Basis
Total	34,680	39,864
Level 1 \| Certificate of deposit
Fair Value on a Recurring Basis
Total	272	271
Level 2
Fair Value on a Recurring Basis
Total	342,756	115,901
Level 2 \| U.S. Treasury securities
Fair Value on a Recurring Basis
Total		12,921
Level 2 \| Municipal securities
Fair Value on a Recurring Basis
Total		2,976
Level 2 \| Government-sponsored enterprise securities
Fair Value on a Recurring Basis
Total	96,615	9,846
Level 2 \| Commercial paper
Fair Value on a Recurring Basis
Total	202,182	64,199
Level 2 \| Corporate notes
Fair Value on a Recurring Basis
Total	$ 43,959	$ 25,959

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Deficit	Accumulated Other Comprehensive Gain (Loss)
Balances at Dec. 31, 2021	$ 126,416	$ 324	$ 1,398,006	$ (1,271,741)	$ (173)
Balances (in shares) at Dec. 31, 2021		323,731,591
Increase (Decrease) in Stockholders' Equity
Net loss	(30,098)			(30,098)
Other comprehensive income (loss)	(539)				(539)
Foreign currency translation adjustment	1				1
Stock-based compensation related to issuance of common stock and options in exchange for services	15		15
Stock-based compensation related to issuance of common stock and options in exchange for services (in shares)		5,284
Stock-based compensation for equity-based awards to employees and directors	1,692		1,692
Balances at Mar. 31, 2022	97,487	$ 324	1,399,713	(1,301,839)	(711)
Balances (in shares) at Mar. 31, 2022		323,736,875
Balances at Dec. 31, 2021	126,416	$ 324	1,398,006	(1,271,741)	(173)
Balances (in shares) at Dec. 31, 2021		323,731,591
Increase (Decrease) in Stockholders' Equity
Net loss	(58,215)
Other comprehensive income (loss)	(621)
Foreign currency translation adjustment	12
Balances at Jun. 30, 2022	142,047	$ 378	1,472,407	(1,329,956)	(782)
Balances (in shares) at Jun. 30, 2022		377,664,759
Balances at Mar. 31, 2022	97,487	$ 324	1,399,713	(1,301,839)	(711)
Balances (in shares) at Mar. 31, 2022		323,736,875
Increase (Decrease) in Stockholders' Equity
Net loss	(28,117)			(28,117)
Other comprehensive income (loss)	(82)				(82)
Foreign currency translation adjustment	11				11
Issuance of common stock and pre-funded warrant to purchase common stock in public offering, net of issuance costs	69,916	$ 53	69,863
Issuance of common stock and pre-funded warrant to purchase common stock in public offering, net of issuance costs (in shares)		53,333,334
Stock-based compensation related to issuance of common stock and options in exchange for services	13		13
Stock-based compensation related to issuance of common stock and options in exchange for services (in shares)		4,637
Issuance of common stock under equity plans	761	$ 1	760
Issuance of common stock under equity plans (in shares)		589,913
Stock-based compensation for equity-based awards to employees and directors	2,058		2,058
Balances at Jun. 30, 2022	142,047	$ 378	1,472,407	(1,329,956)	(782)
Balances (in shares) at Jun. 30, 2022		377,664,759
Balances at Dec. 31, 2022	79,998	$ 390	1,493,469	(1,413,642)	(219)
Balances (in shares) at Dec. 31, 2022		390,262,524
Increase (Decrease) in Stockholders' Equity
Net loss	(38,122)			(38,122)
Other comprehensive income (loss)	75				75
Foreign currency translation adjustment	(16)				(16)
Issuance of common stock and pre-funded warrant to purchase common stock in public offering, net of issuance costs	213,337	$ 68	213,269
Issuance of common stock and pre-funded warrant to purchase common stock in public offering, net of issuance costs (in shares)		68,007,741
Issuance of common stock in connection with exercise of warrants	59,835	$ 45	59,790
Issuance of common stock in connection exercise of warrants (in shares)		44,983,193
Stock-based compensation related to issuance of common stock and options in exchange for services	112	$ 1	111
Stock-based compensation related to issuance of common stock and options in exchange for services (in shares)		9,360
Issuance of common stock under equity plans	7,875	$ 5	7,870
Issuance of common stock under equity plans (in shares)		5,469,028
Stock-based compensation for equity-based awards to employees and directors	2,961		2,961
Balances at Mar. 31, 2023	326,055	$ 509	1,777,470	(1,451,764)	(160)
Balances (in shares) at Mar. 31, 2023		508,731,846
Balances at Dec. 31, 2022	79,998	$ 390	1,493,469	(1,413,642)	(219)
Balances (in shares) at Dec. 31, 2022		390,262,524
Increase (Decrease) in Stockholders' Equity
Net loss	(87,349)
Other comprehensive income (loss)	(711)
Foreign currency translation adjustment	(15)
Balances at Jun. 30, 2023	298,427	$ 522	1,799,841	(1,500,991)	(945)
Balances (in shares) at Jun. 30, 2023		521,942,104
Balances at Mar. 31, 2023	326,055	$ 509	1,777,470	(1,451,764)	(160)
Balances (in shares) at Mar. 31, 2023		508,731,846
Increase (Decrease) in Stockholders' Equity
Net loss	(49,227)			(49,227)
Other comprehensive income (loss)	(786)				(786)
Foreign currency translation adjustment	1				1
Issuance of common stock in connection with exercise of warrants	17,767	$ 13	17,754
Issuance of common stock in connection exercise of warrants (in shares)		12,842,857
Stock-based compensation related to issuance of common stock and options in exchange for services	99		99
Stock-based compensation related to issuance of common stock and options in exchange for services (in shares)		6,327
Issuance of common stock under equity plans	573		573
Issuance of common stock under equity plans (in shares)		361,074
Stock-based compensation for equity-based awards to employees and directors	3,945		3,945
Balances at Jun. 30, 2023	$ 298,427	$ 522	$ 1,799,841	$ (1,500,991)	$ (945)
Balances (in shares) at Jun. 30, 2023		521,942,104

FAIR VALUE MEASUREMENTS - SECURITIES WITH UNREALIZED LOSSES (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Schedule Of Available For Sale Securities [Line Items]
Less Than 12 Months - Estimated Fair Value	$ 284,997	$ 75,721
Less Than 12 Months - Gross Unrealized Losses	(980)	(165)
12 Months or Longer - Estimated Fair Value		28,435
12 Months or Longer - Gross Unrealized Losses		(82)
Total - Estimated Fair Value	284,997	104,156
Total - Gross Unrealized Losses	(980)	(247)
U.S. Treasury securities (due in less than one year)
Schedule Of Available For Sale Securities [Line Items]
Less Than 12 Months - Estimated Fair Value		11,424
Less Than 12 Months - Gross Unrealized Losses		(57)
12 Months or Longer - Estimated Fair Value		1,497
12 Months or Longer - Gross Unrealized Losses		(5)
Total - Estimated Fair Value		12,921
Total - Gross Unrealized Losses		(62)
Municipal securities (due in less than one year)
Schedule Of Available For Sale Securities [Line Items]
12 Months or Longer - Estimated Fair Value		2,976
12 Months or Longer - Gross Unrealized Losses		(24)
Total - Estimated Fair Value		2,976
Total - Gross Unrealized Losses		(24)
Government-sponsored enterprise securities (due in less than one year)
Schedule Of Available For Sale Securities [Line Items]
Less Than 12 Months - Estimated Fair Value	58,651	9,845
Less Than 12 Months - Gross Unrealized Losses	(224)	(14)
Total - Estimated Fair Value	58,651	9,845
Total - Gross Unrealized Losses	(224)	(14)
Government-sponsored enterprise securities (due in one to two years)
Schedule Of Available For Sale Securities [Line Items]
Less Than 12 Months - Estimated Fair Value	18,538
Less Than 12 Months - Gross Unrealized Losses	(141)
Total - Estimated Fair Value	18,538
Total - Gross Unrealized Losses	(141)
Commercial paper (due in less than one year)
Schedule Of Available For Sale Securities [Line Items]
Less Than 12 Months - Estimated Fair Value	169,851	52,454
Less Than 12 Months - Gross Unrealized Losses	(365)	(92)
Total - Estimated Fair Value	169,851	52,454
Total - Gross Unrealized Losses	(365)	(92)
Corporate notes (due in less than one year)
Schedule Of Available For Sale Securities [Line Items]
Less Than 12 Months - Estimated Fair Value	29,211	1,998
Less Than 12 Months - Gross Unrealized Losses	(138)	(2)
12 Months or Longer - Estimated Fair Value		23,962
12 Months or Longer - Gross Unrealized Losses		(53)
Total - Estimated Fair Value	29,211	25,960
Total - Gross Unrealized Losses	(138)	$ (55)
Corporate notes (due in one to two years)
Schedule Of Available For Sale Securities [Line Items]
Less Than 12 Months - Estimated Fair Value	8,746
Less Than 12 Months - Gross Unrealized Losses	(112)
Total - Estimated Fair Value	8,746
Total - Gross Unrealized Losses	$ (112)

DOCUMENT AND ENTITY INFORMATION - shares	6 Months Ended
DOCUMENT AND ENTITY INFORMATION - shares	Jun. 30, 2023	Jul. 27, 2023
Cover [Abstract]
Entity Registrant Name	GERON CORP
Entity Central Index Key	0000886744
Document Type	10-Q
Document Period End Date	Jun. 30, 2023
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		523,370,675
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q2
Trading Symbol	GERN
Entity File Number	000-20859
Entity Tax Identification Number	75-2287752
Entity Shell Company	false
Entity Address, Address Line One	919 EAST HILLSDALE BOULEVARD
Entity Address, Address Line Two	SUITE 250
Entity Address, City or Town	FOSTER CITY
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94404
City Area Code	650
Local Phone Number	473-7700
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common Stock, $0.001 par value
Security Exchange Name	NASDAQ
Entity Incorporation, State or Country Code	DE
Document Quarterly Report	true
Document Transition Report	false

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Revenues:
Royalties	$ 29	$ 73	$ 50	$ 196
Operating expenses:
Research and development	35,490	20,606	62,709	42,705
General and administrative	16,490	7,443	29,384	14,142
Total operating expenses	51,980	28,049	92,093	56,847
Loss from operations	(51,951)	(27,976)	(92,043)	(56,651)
Interest income	4,738	330	8,591	442
Interest expense	(2,003)	(1,581)	(3,925)	(3,060)
Other income and (expense), net	(11)	1,110	28	1,054
Net loss	$ (49,227)	$ (28,117)	$ (87,349)	$ (58,215)
Basic net loss per share	$ (0.09)	$ (0.07)	$ (0.16)	$ (0.16)
Diluted net loss per share	$ (0.09)	$ (0.07)	$ (0.16)	$ (0.16)
Shares used in computing basic net loss per share	547,280,946	403,868,713	553,772,809	368,166,148
Shares used in computing diluted net loss per share	547,280,946	403,868,713	553,772,809	368,166,148

STOCKHOLDERS' EQUITY - WARRANT EXERCISES (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2023
Class of Warrant or Right [Line Items]
Proceeds from exercise of warrants			$ 77,602,000
Pre-Funded Warrants
Class of Warrant or Right [Line Items]
Warrant exercise price	$ 0.001		$ 0.001
Common stock outstanding warrants to purchase	51,430,477		51,430,477
2020 Public Offering of Common Stock and Warrants \| Stock Purchase Warrants
Class of Warrant or Right [Line Items]
Warrant exercise price	$ 1.3		$ 1.3
Common stock outstanding warrants to purchase	2,474,503		2,474,503
2022 Underwritten Public Offering \| Stock Purchase Warrants
Class of Warrant or Right [Line Items]
Warrant exercise price	$ 1.45		$ 1.45
Common stock outstanding warrants to purchase	19,523,812		19,523,812
Underwritten Public Offering \| Stock Purchase Warrants
Class of Warrant or Right [Line Items]
Warrants to purchase common stock exercised, shares	12,842,857	44,983,194	12,842,857
Proceeds from exercise of warrants	$ 17,767,000	$ 59,835,000

ACCRUED LIABILITIES (Tables)

6 Months Ended

Jun. 30, 2023

Payables and Accruals [Abstract]

Schedule of accrued liabilities

Accrued liabilities consisted of the following as of June 30, 2023 and December 31, 2022:


	JUNE 30,		DECEMBER 31,
(In thousands)	2023		2022
CRO and clinical trial costs	$	22,776	$	17,040
Manufacturing activities		11,798		5,321
Legal settlements		7,000		8,350
Professional legal and accounting fees		857		1,318
Interest payable		584		561
Other		2,021		510
	$	45,036	$	33,100