Geron (GERN) 10-Q7 Nov 132013 Q3 Quarterly reportFinancial data

Company Profile

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
Document and Entity Information	Sep. 30, 2013	Nov. 01, 2013
Document and Entity Information	'	'
Entity Registrant Name	'GERON CORP	'
Entity Central Index Key	'0000886744	'
Document Type	'10-Q	'
Document Period End Date	30-Sep-13	'
Amendment Flag	'false	'
Current Fiscal Year End Date	'--12-31	'
Entity Current Reporting Status	'Yes	'
Entity Filer Category	'Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	128,967,411
Document Fiscal Year Focus	'2013	'
Document Fiscal Period Focus	'Q3	'

CONDENSED_CONSOLIDATED_BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Current assets:	'	'
Cash and cash equivalents	$9,591	$22,063
Restricted cash	795	794
Marketable securities	56,617	73,472
Interest and other receivables	555	752
Prepaid assets	844	1,336
Total current assets	68,402	98,417
Property and equipment, net	116	974
Deposits and other assets	195	410
Total assets	68,713	99,801
Current liabilities:	'	'
Accounts payable	1,547	3,429
Accrued compensation and benefits	2,886	5,216
Accrued restructuring charges	161	1,972
Accrued liabilities	1,985	3,480
Fair value of derivatives	258	51
Total current liabilities	6,837	14,148
Commitments and contingencies	'	'
Stockholders' equity:	'	'
Common stock	129	130
Additional paid-in capital	945,241	939,867
Accumulated deficit	-883,482	-854,384
Accumulated other comprehensive (loss) income	-12	40
Total stockholders' equity	61,876	85,653
Total liabilities and stockholders' equity	$68,713	$99,801

CONDENSED_CONSOLIDATED_STATEME

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Revenues:	'	'	'	'
License fees and royalties	$181	$636	$1,058	$2,020
Operating expenses:	'	'	'	'
Research and development	5,338	11,684	18,066	39,568
Restructuring charges	116	'	1,032	'
General and administrative	3,460	4,829	11,643	15,726
Total operating expenses	8,914	16,513	30,741	55,294
Loss from operations	-8,733	-15,877	-29,683	-53,274
Unrealized loss on derivatives	-208	-44	-207	-10
Interest and other income	699	140	836	481
Interest and other expense	-12	-172	-44	-215
Net loss	($8,254)	($15,953)	($29,098)	($53,018)
Basic and diluted net loss per share (in dollars per share)	($0.06)	($0.13)	($0.23)	($0.42)
Shares used in computing basic and diluted net loss per share (in shares)	128,293,074	127,236,993	128,146,333	126,833,916

CONDENSED_CONSOLIDATED_STATEME1

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS	'	'	'	'
Net loss	($8,254)	($15,953)	($29,098)	($53,018)
Other comprehensive income (loss):	'	'	'	'
Net unrealized gain (loss) on available-for-sale securities	1	10	-52	4
Foreign currency translation adjustments	'	'	'	16
Reclassification of foreign currency translation adjustments	'	153	'	153
Other comprehensive income (loss)	1	163	-52	173
Comprehensive loss	($8,253)	($15,790)	($29,150)	($52,845)

CONDENSED_CONSOLIDATED_STATEME2

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Cash flows from operating activities:	'	'
Net loss	($29,098)	($53,018)
Adjustments to reconcile net loss to net cash used in operating activities:	'	'
Depreciation and amortization	357	658
Accretion and amortization on investments, net	948	1,806
Gain on sales of property and equipment, net	-759	-32
Loss on write-downs of property and equipment	200	'
Stock-based compensation for services by non-employees	136	152
Stock-based compensation for employees and directors	3,456	4,016
Amortization related to 401(k) contributions	449	336
Unrealized loss on derivatives	207	10
Changes in assets and liabilities:	'	'
Other current and noncurrent assets	904	1,941
Other current liabilities	-6,679	-768
Translation adjustment	'	169
Net cash used in operating activities	-29,879	-44,730
Cash flows from investing activities:	'	'
Restricted cash transfer	-1	-1
Purchases of property and equipment	-56	-854
Proceeds from sales of property and equipment	1,116	38
Purchases of marketable securities	-57,446	-54,905
Proceeds from maturities of marketable securities	73,301	100,275
Net cash provided by investing activities	16,914	44,553
Cash flows from financing activities:	'	'
Proceeds from issuance of common stock, net of issuance costs	493	80
Net cash provided by financing activities	493	80
Net decrease in cash and cash equivalents	-12,472	-97
Cash and cash equivalents at the beginning of the period	22,063	16,105
Cash and cash equivalents at the end of the period	$9,591	$16,008

SUMMARY_OF_SIGNIFICANT_ACCOUNT

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

9 Months Ended

Sep. 30, 2013

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

1. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Basis of Presentation

The terms “Geron”, the “Company”, “we” and “us” as used in this report refer to Geron Corporation. 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 U.S. generally accepted accounting principles for complete financial statements. In the opinion of management of Geron, all adjustments (consisting only of normal recurring accruals) considered necessary for a fair presentation have been included. Operating results for the three and nine month periods ended September 30, 2013 are not necessarily indicative of the results that may be expected for the year ending December 31, 2013 or any other period. These financial statements and notes should be read in conjunction with the financial statements for each of the three years ended December 31, 2012, included in the Company’s Annual Report on Form 10-K. The accompanying condensed consolidated balance sheet as of December 31, 2012 has been derived from audited financial statements at that date.

Principles of Consolidation

The 2012 condensed consolidated financial statements include the accounts of Geron and our former wholly-owned subsidiary, Geron Bio-Med Ltd. (Geron Bio-Med), a United Kingdom company. In March 2012, the board of directors and shareholders of Geron Bio-Med approved actions to commence a voluntary winding up of the company. The full wind up of Geron Bio-Med was completed in August 2012. Prior to 2013, we eliminated intercompany accounts and transactions and prepared the financial statements of Geron Bio-Med using the local currency as the functional currency. We translated the assets and liabilities of Geron Bio-Med at rates of exchange at the balance sheet date and translated income and expense items at average monthly rates of exchange. The resultant translation adjustments were included in accumulated other comprehensive income (loss), a separate component of stockholders’ equity.

Net Loss Per Share

Basic earnings (loss) per share is calculated based on the weighted average number of shares of common stock outstanding during the period. Diluted earnings (loss) per share is calculated based on the weighted average number of shares of common stock and potential dilutive securities outstanding during the period. Potential dilutive securities primarily consist of outstanding stock options, restricted stock and warrants to purchase common stock and are determined using the treasury stock method at an average market price during the period.

Because we are in a net loss position, diluted loss per share excludes the effects of potential dilutive securities. Had we been in a net income position, diluted earnings per share would have included the shares used in the computation of basic net loss per share as well as an additional 7,183 and 16,061 shares for the 2013 and 2012 periods, respectively, related to outstanding stock options, restricted stock and warrants (as determined using the treasury stock method at the estimated average market value).

Use of Estimates

The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires us to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. On a regular basis, management evaluates these estimates and assumptions. 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. We place our cash and cash equivalents in money market funds and cash operating accounts. Our marketable securities include U.S. government-sponsored enterprise securities, commercial paper and corporate notes with original maturities ranging from five to 16 months.

We classify our marketable securities as available-for-sale. We record available-for-sale 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 and other 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 and other income in our condensed consolidated statements of operations. We recognize a charge when the declines in the fair values below the amortized cost basis of our available-for-sale securities are judged to be other-than-temporary. We consider various factors in determining whether to recognize an other-than-temporary charge, including whether we intend to sell the security or whether it is more likely than not that we would be required to sell the security. Declines in market value associated with credit losses judged as other-than-temporary result in a charge to interest and other income. Other-than-temporary charges not related to credit losses are included in accumulated other comprehensive income (loss) in stockholders’ equity. No other-than-temporary impairment charges were recorded for our available-for-sale securities for the three and nine months ended September 30, 2013 and 2012. See Note 2 on Fair Value Measurements.

Fair Value of Derivatives

For non-employee options classified as assets or liabilities, the fair value of these instruments is recorded on the condensed consolidated balance sheet at inception and adjusted to fair value at each financial reporting date. The change in fair value of the non-employee options is recorded in the condensed consolidated statements of operations as unrealized gain (loss) on derivatives. Fair value of non-employee options is estimated using the Black Scholes option-pricing model. The non-employee options continue to be reported as an asset or liability until such time as the instruments are exercised or expire or are otherwise modified to remove the provisions which require this treatment, at which time these instruments are marked to fair value and reclassified from assets or liabilities to stockholders’ equity. For non-employee options classified as permanent equity, the fair value of the non-employee options is recorded in stockholders’ equity as of their respective vesting dates and no further adjustments are made. See Note 2 on Fair Value Measurements.

Revenue Recognition

We have entered into several license agreements with various oncology, diagnostics, research tools, agriculture and biologics production companies. With certain of these agreements, we receive nonrefundable license payments in cash or equity securities, option payments in cash or equity securities, cost reimbursements, milestone payments, royalties on future sales of products, or any combination of these items. Upfront non-refundable signing, license or non-exclusive option fees are recognized as revenue when rights to use the intellectual property related to the license have been delivered and over the term of the agreement if we have continuing performance obligations. Milestone payments, which are subject to substantive contingencies, are recognized upon completion of specified milestones, representing the culmination of the earnings process, according to contract terms. Royalties are generally recognized upon receipt of the related royalty payment. Deferred revenue represents the portion of research and license payments received which has not been earned. When payments are received in equity securities, we do not recognize any revenue unless such securities are determined to be realizable in cash. We recognize revenue under collaborative agreements as the related research and development services are rendered.

Restricted Cash

Restricted cash consists of funds maintained in separate certificate of deposit accounts for specified purposes. The components of restricted cash were as follows:

September 30,

December 31,

(In thousands)

2013

2012

Certificate of deposit for unused equipment line of credit

530

Certificate of deposit for credit card purchases

265

264

795

794

Research and Development Expenses

Research and development expenses consist of expenses incurred in identifying, developing and testing product candidates resulting from our independent efforts as well as efforts associated with collaborations. These expenses include, but are not limited to, acquired in-process research and development deemed to have no alternative future use, payroll and personnel expense, lab supplies, preclinical studies, clinical trials, including support for investigator-sponsored 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. Research and development costs are expensed as incurred, including payments made under our license agreements.

Clinical Trial Costs

A significant component of our research and development expenses is clinical trial costs. Substantial portions of our preclinical studies and all of our clinical trials have been performed by third-party contract research organizations, or CROs, and other vendors. We accrue expenses for preclinical studies performed by our vendors based on certain estimates over the term of the service period and adjust our estimates as required. We accrue expenses for clinical trial activities performed by CROs based upon the estimated amount of work completed on each study. For clinical trial expenses, 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 study. Pass through costs from CROs include, but are not limited to, regulatory expenses, investigator fees, lab fees, travel costs and other miscellaneous costs, including shipping and printing fees. We accrue pass through costs based on estimates of the amount of work completed for the clinical 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 would allow us to make a more accurate estimate in future periods. In this 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 recognize stock-based compensation expense on a straight-line basis over the requisite service period, which is generally the vesting period. The following table summarizes the stock-based compensation expense related to stock options, restricted stock awards and employee stock purchases for the three and nine months ended September 30, 2013 and 2012 which was allocated as follows:

Three Months Ended

Nine Months Ended

September 30,

(In thousands)

2013

2012

2013

2012

Research and development

483

594

1,394

1,861

Restructuring charges

—

General and administrative

739

669

2,034

2,155

Stock-based compensation expense included in operating expenses

1,222

1,263

3,456

4,016

Modifications to the post-termination exercise period of outstanding options held by certain members of our executive management team resulted in additional stock-based compensation expense of $205,000 for the three and nine months ended September 30, 2013. In addition, stock-based compensation expense has been recognized for the modification of the post-termination exercise period for certain stock options previously granted to employees affected by the April 2013 restructuring. Stock-based compensation resulting from these modifications has been reflected in the table above. See Note 3 on Restructurings for a further discussion of the April 2013 restructuring.

As stock-based compensation expense recognized in the condensed consolidated statements of operations for the three and nine months ended September 30, 2013 and 2012 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.

Stock Options

We grant options with service-based vesting under our equity plans to employees, non-employee directors and consultants. The vesting period for employee options is generally four years. The fair value of options granted during the nine months ended September 30, 2013 and 2012 has been estimated at the date of grant using the Black Scholes option-pricing model with the following assumptions:

Nine Months Ended September 30,

2013

2012

Dividend yield

None

Expected volatility range

0.742 to 0.759

0.631 to 0.726

Risk-free interest rate range

0.80% to 1.81%

0.81% to 1.25%

Expected term

6 yrs

Employee Stock Purchase Plan

The fair value of employees’ purchase rights during the nine months ended September 30, 2013 and 2012 has been estimated using the Black Scholes option-pricing model with the following assumptions:

Nine Months Ended September 30,

2013

2012

Dividend yield

None

Expected volatility range

0.506 to 1.391

0.458 to 0.774

Risk-free interest rate range

0.09% to 0.21%

0.06% to 0.21%

Expected term range

6 - 12 mos

Dividend yield is based on historical cash dividend payments. The expected volatility range is based on historical volatilities of our stock since traded options on Geron 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 options is derived from actual historical exercise and post-vesting cancellation data and represents the period of time that options granted are expected to be outstanding. The expected term of employees’ purchase rights is equal to the purchase period.

Restricted Stock Awards

We grant restricted stock awards to employees and non-employee directors with three types of vesting schedules: (i) service-based, (ii) performance-based or (iii) market-based. Service-based restricted stock awards generally vest annually over four years. Performance-based restricted stock awards vest upon achievement of discrete strategic corporate goals within a specified performance period, generally three years. Market-based restricted stock awards vest upon achievement of certain market price thresholds of our common stock within a specified performance period, generally three years.

The fair value for service-based restricted stock awards is determined using the fair value of our common stock on the date of grant. The fair value is amortized as stock-based compensation expense over the requisite service period of the award, which is generally the vesting period, on a straight-line basis and is reduced for estimated forfeitures, as applicable.

The fair value for performance-based restricted stock awards is determined using the fair value of our common stock on the date of grant. Stock-based compensation expense for awards with vesting based on performance conditions 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 that assessment of the probability of the performance condition being met changes, the impact of the change in estimate would be recognized in the period of the change. If the requisite service period has been met prior to the change in estimate, the effect of the change in estimate would be immediately recognized. We have not recognized any stock-based compensation expense for performance-based restricted stock awards in our condensed consolidated statements of operations for the three and nine months ended September 30, 2013 and 2012 as the achievement of the specified performance criteria was not considered probable during that time.

The fair value for market-based restricted stock awards is determined using a lattice valuation model with a Monte Carlo simulation. The model takes into consideration the historical volatility of our stock and the risk-free interest rate at the date of grant. In addition, the model is used to estimate the derived service period for the awards. The derived service period is the estimated period of time that would be required to satisfy the market condition, assuming the market condition will be satisfied. Stock-based compensation expense is recognized over the derived service period for the awards using the straight-line method and is reduced for estimated forfeitures, as applicable, but is accelerated if the market condition is achieved earlier than estimated. All market-based restricted stock awards have been cancelled as of September 30, 2013 as the market conditions were not achieved within the specified performance period.

Non-Employee Stock-Based Awards

For our non-employee stock-based awards, the measurement date on which the fair value of the stock-based award is calculated is equal to the earlier of (i) the date at which a commitment for performance by the counterparty to earn the equity instrument is reached or (ii) the date at which the counterparty’s performance is complete. We recognize stock-based compensation expense for the fair value of the vested portion of non-employee awards in our condensed consolidated statements of operations.

FAIR_VALUE_MEASUREMENTS

FAIR VALUE MEASUREMENTS	9 Months Ended
FAIR VALUE MEASUREMENTS	Sep. 30, 2013
FAIR VALUE MEASUREMENTS	'
FAIR VALUE MEASUREMENTS	'
	2. FAIR VALUE MEASUREMENTS

	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. Below is a description of the valuation methodologies used for financial instruments measured at fair value on our condensed consolidated balance sheets, including the category for such financial instruments.

	Cash Equivalents and Marketable Securities Available-for-Sale

	Certificates of deposit and 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, U.S. government-sponsored enterprise securities, municipal securities, corporate notes and commercial paper 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.

	Cash equivalents, restricted cash and marketable securities by security type at September 30, 2013 were as follows:

						Gross			Gross
			Amortized			Unrealized			Unrealized			Estimated
			Cost			Gains			Losses			Fair Value
			(In thousands)
	Included in cash and cash equivalents:
	Money market funds		$	5,997		$	—		$	—		$	5,997
	Restricted cash:
	Certificates of deposit		$	795		$	—		$	—		$	795
	Marketable securities (due in less than 1 year):
	Government-sponsored enterprise securities		$	7,319		$	1		$	—		$	7,320
	Commercial paper		15,741			9			—			15,750
	Corporate notes		33,569			—			(22		)	33,547
			$	56,629		$	10		$	(22	)	$	56,617

	Cash equivalents, restricted cash and marketable securities by security type at December 31, 2012 were as follows:

						Gross			Gross
			Amortized			Unrealized			Unrealized			Estimated
			Cost			Gains			Losses			Fair Value
			(In thousands)
	Included in cash and cash equivalents:
	Money market funds		$	15,660		$	—		$	—		$	15,660
	Corporate notes		3,136			—			(1		)	3,135
			$	18,796		$	—		$	(1	)	$	18,795
	Restricted cash:
	Certificates of deposit		$	794		$	—		$	—		$	794
	Marketable securities (due in less than 1 year):
	Government-sponsored enterprise securities		$	8,618		$	5		$	—		$	8,623
	Commercial paper		20,623			21			—			20,644
	Corporate notes		44,190			22			(7		)	44,205
			$	73,431		$	48		$	(7	)	$	73,472

	Marketable securities with unrealized losses at September 30, 2013 and December 31, 2012 were as follows:

			Less Than 12 Months						12 Months or Greater						Total
						Gross						Gross						Gross
			Estimated			Unrealized			Estimated			Unrealized			Estimated			Unrealized
			Fair Value			Losses			Fair Value			Losses			Fair Value			Losses
			(In thousands)
	As of September 30, 2013:
	Corporate notes (due in less than 1 year)		$	31,654		$	(22	)	$	—		$	—		$	31,654		$	(22	)

	As of December 31, 2012:
	Corporate notes (due in less than 1 year)		$	27,045		$	(8	)	$	—		$	—		$	27,045		$	(8	)

The gross unrealized losses related to corporate notes as of September 30, 2013 and December 31, 2012 were due to changes in interest rates. We determined that the gross unrealized losses on our marketable securities as of September 30, 2013 and December 31, 2012 were temporary in nature. We review our investments quarterly to identify and evaluate whether any investments have indications of possible impairment. Factors considered in determining whether a loss is temporary include the length of time and extent to which the fair value has been less than the cost basis and whether we intend to sell the security or whether it is more likely than not that we would be required to sell the security. We currently do not intend to sell these securities before recovery of their amortized cost basis.

Derivatives

Non-employee options are normally traded less actively, have trade activity that is one way, and/or traded in less-developed markets and are therefore valued based upon models with significant unobservable market parameters, resulting in Level 3 categorization.

Options held by non-employees whose performance obligations are complete are classified as derivative liabilities on our condensed consolidated balance sheets. Upon the exercise of these options, the instruments are marked to fair value and reclassified from derivative liabilities to stockholders’ equity. There were no reclassifications from current liabilities to stockholders’ equity for non-employee option exercises during 2013.

As of September 30, 2013 and December 31, 2012, the following non-employee options to purchase common stock were considered derivatives and classified as current liabilities:

									At September 30, 2013					At December 31, 2012
									Number		Fair			Number		Fair
Issuance		Exercise			Exercisable		Expiration		of		Value			of		Value
Date		Price			Date		Date		Shares		(In thousands)			Shares		(In thousands)
March 2005		$	6.39		January 2007		March 2015		284,600		$	258		284,600		$	51


The fair value of derivatives has been calculated at each reporting date using the Black Scholes option-pricing model with the following assumptions:

		September 30, 2013		December 31, 2012
Dividend yield		None		None
Expected volatility		0.955		0.828
Risk-free interest rate		0.33%		0.25%
Expected term		2 yrs		2 yrs

Dividend yield is based on historical cash dividend payments. The expected volatility is based on historical volatilities of our stock since traded options on Geron stock do not correspond to derivatives’ terms and trading volume of Geron options is limited. The risk-free interest rate is based on the U.S. Zero Coupon Treasury Strip Yields for the expected term of the derivatives in effect on the reporting date. The expected term of derivatives is equal to the remaining contractual term of the instruments.

Fair Value on a Recurring Basis

The following table presents information about our financial instruments that are measured at fair value on a recurring basis as of September 30, 2013 and indicates the fair value category assigned.

		Fair Value Measurements at Reporting Date Using
		Quoted Prices in			Significant
		Active Markets			Other			Significant
		for Identical			Observable			Unobservable
		Assets / Liabilities			Inputs			Inputs
(In thousands)		Level 1			Level 2			Level 3			Total
Assets
Money market funds (1)		$	5,997		$	—		$	—		$	5,997
Government-sponsored enterprise securities (2)		—			7,320			—			7,320
Commercial paper (2)		—			15,750			—			15,750
Corporate notes (2)		—			33,547			—			33,547
Total		$	5,997		$	56,617		$	—		$	62,614

Liabilities
Derivatives (3)		$	—		$	—		$	258		$	258

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

(2) Included in current marketable securities on our condensed consolidated balance sheets.

(3) Included in fair value of derivatives on our condensed consolidated balance sheets.

Changes in Level 3 Recurring Fair Value Measurements

The table below includes a rollforward of the balance sheet amounts for the three and nine months ended September 30, 2013, including the change in fair value, for financial instruments in the Level 3 category. When a determination is made to classify a financial instrument within Level 3, the determination is based upon the significance of the unobservable parameters to the overall fair value measurement. However, Level 3 financial instruments typically include, in addition to the unobservable components, observable components (that is, components that are actively quoted and can be validated to external sources). Accordingly, the gains and losses in the table below include changes in fair value due in part to observable factors that are part of the methodology.

					Fair Value Measurements Using Significant Unobservable Inputs (Level 3)
					Three Months Ended September 30, 2013
																				Change in
																				Unrealized Loss
					Total															Related to
					Unrealized									Transfers						Financial
		Fair Value at			Loss			Purchases						In and/or			Fair Value at			Instruments
		June 30,			Included in			and			Sales and			Out of			September 30,			Held at
(In thousands)		2013			Earnings (1)			Issuances			Settlements			Level 3			2013			September 30, 2013 (1)
Derivative liabilities		$	50		$	208		$	—		$	—		$	—		$	258		$	208


					Fair Value Measurements Using Significant Unobservable Inputs (Level 3)
					Nine Months Ended September 30, 2013
																				Change in
																				Unrealized Loss
					Total															Related to
					Unrealized									Transfers						Financial
		Fair Value at			Loss			Purchases						In and/or			Fair Value at			Instruments
		December 31,			Included in			and			Sales and			Out of			September 30,			Held at
(In thousands)		2012			Earnings (1)			Issuances			Settlements			Level 3			2013			September 30, 2013 (1)
Derivative liabilities		$	51		$	207		$	—		$	—		$	—		$	258		$	207


(1) Reported as unrealized loss on derivatives in our condensed consolidated statements of operations.

RESTRUCTURINGS

RESTRUCTURINGS	9 Months Ended
	Sep. 30, 2013
RESTRUCTURINGS	'
RESTRUCTURINGS	'
	3. RESTRUCTURINGS

	On April 25, 2013, we announced the decision to discontinue our discovery research programs and companion diagnostics program based on telomere length and close our research laboratory facility located at 200 Constitution Drive, Menlo Park, California. With this decision, a total of 20 positions were eliminated. In connection with this restructuring, we expect to record aggregate restructuring charges of approximately $1,500,000, of which $940,000 was recorded during the nine months ended September 30, 2013. As of September 30, 2013, the restructuring charges recognized under the April 2013 restructuring included $624,000 related to one-time termination benefits, including $28,000 of non-cash stock-based compensation expense relating to the extension of the post-termination exercise period through the end of December 2013 for certain stock options previously granted to terminated employees, $200,000 related to non-cash charges for write-downs of excess equipment and leasehold improvements and $116,000 related to costs associated with the closure of our research laboratory facility. The remaining projected restructuring charges relate to costs associated with the closure of our research laboratory facility and are expected to be recorded in the fourth quarter of 2013. We expect the restructuring will result in aggregate cash expenditures of approximately $1,250,000, of which $571,000 has been paid as of September 30, 2013 and related to one-time termination benefits and facility-related charges. The remaining cash expenditures are expected to be paid in the fourth quarter of 2013 and relate to facility-related charges. As of September 30, 2013, we have received proceeds of $1,000,000 from the sale of excess laboratory equipment in connection with the closure of our research laboratory facility. We may incur other charges associated with the April 2013 restructuring. Such charges, if any, will be recorded as they are determined.

	On December 3, 2012, we announced the decision to discontinue development of GRN1005. With this decision, a total of 43 positions were eliminated. As of September 30, 2013, we have recognized aggregate restructuring charges of $2,794,000 for the December 2012 restructuring, of which $2,702,000 was recorded in the fourth quarter of 2012 and $92,000 was recorded in the first half of 2013. All actions associated with the December 2012 restructuring were completed in the first half of 2013, and we do not anticipate incurring any further charges in connection with the December 2012 restructuring.

	On November 14, 2011, we announced the decision to focus on the development of our oncology programs and consequently, we discontinued further development of our stem cell programs. With this decision, a total of 66 positions were eliminated. All actions associated with the November 2011 restructuring were completed in 2012, and we do not anticipate incurring any further charges in connection with the November 2011 restructuring. All payments due under the November 2011 restructuring were made as of June 30, 2013.

	The components relating to the April 2013, December 2012 and November 2011 restructurings, including the outstanding restructuring liability which is included in accrued restructuring charges on our condensed consolidated balance sheet as of September 30, 2013, are summarized in the following table:

	(In thousands)	Employee			Asset			Facility Related			Total
		Severance and			Write Downs			Charges
		Other Benefits
	Beginning accrual balance as of December 31, 2012	$	1,972		$	—		$	—		$	1,972
	Restructuring charges	716			200			116			1,032
	Cash payments	(2,373		)	—			(96		)	(2,469		)
	Adjustments or non-cash credits, including stock-based compensation expense	(174		)	(200		)	—			(374		)
	Ending accrual balance as of September 30, 2013	$	141		$	—		$	20		$	161

SEGMENT_INFORMATION

SEGMENT INFORMATION	9 Months Ended
SEGMENT INFORMATION	Sep. 30, 2013
SEGMENT INFORMATION	'
SEGMENT INFORMATION	'
	4. SEGMENT INFORMATION

	Our executive management team represents our chief decision maker. We view our operations as one segment, the discovery and 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.

CONDENSED_CONSOLIDATED_STATEME3

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS DATA	9 Months Ended
	Sep. 30, 2013
CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS DATA	'
CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS DATA	'
	5. CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS DATA

	Supplemental schedule of non-cash operating and investing activities:

		Nine Months Ended
		September 30,
	(In thousands)	2013			2012
	Supplemental Operating Activities:
	Issuance of common stock for 401(k) matching contributions	$	839		$	1,361
	Issuance of common stock for services rendered to date or to be received in future periods	—			69
	Reclassification of deposits to other current assets, net	219			135
	Supplemental Investing Activities:
	Net unrealized (loss) gain on available-for-sale securities	(52		)	4

SUBSEQUENT_EVENT

SUBSEQUENT EVENT	9 Months Ended
SUBSEQUENT EVENT	Sep. 30, 2013
SUBSEQUENT EVENT	'
SUBSEQUENT EVENT	'
	6. SUBSEQUENT EVENT

	On October 1, 2013, we closed the transaction to divest our human embryonic stem cell assets and our autologous cellular immunotherapy program pursuant to the terms of the previously disclosed Asset Contribution Agreement, or the Agreement, we entered into in January 2013 with BioTime, Inc., or BioTime, and BioTime’s wholly owned subsidiary, Asterias Biotherapeutics, Inc., or Asterias (formerly known as BioTime Acquisition Corporation).

	Under the terms of the Agreement, on October 1, 2013, we contributed to Asterias our human embryonic stem cell assets, including intellectual property, human embryonic stem cell lines and other assets related to our discontinued human embryonic stem cell programs, including our Phase I clinical trial of oligodendrocyte progenitor cells, or GRNOPC1, in patients with acute spinal cord injury, as well as our autologous cellular immunotherapy program, including data from the Phase I/II clinical trial of the autologous cellular immunotherapy in patients with acute myelogenous leukemia. On October 1, 2013, Asterias assumed all post-closing liabilities with respect to all of the assets contributed by us, including any liabilities related to the GRNOPC1 and autologous cellular immunotherapy clinical trials. Additionally, Asterias was substituted for us as a party in an appeal by us of two rulings in favor of ViaCyte, Inc. by the United States Patent and Trademark Office’s Board of Patent Appeals and Interferences, filed by us in the United States District Court for the Northern District of California in September 2012, or the ViaCyte Appeal, and Asterias assumed all liabilities arising after October 1, 2013 with respect to the ViaCyte Appeal.

	As consideration for the contribution of our human embryonic stem cell assets and autologous cellular immunotherapy program to Asterias, on October 1, 2013 we received 6,537,779 shares of Asterias Series A common stock representing 21.4% of Asterias’ outstanding common stock as a class as of that date. We are also entitled to receive royalties from Asterias on the sale of products that are commercialized, if any, in reliance upon the patents we contributed to Asterias. Under the terms of the Agreement and subject to applicable law, following a record date to be declared by our board of directors, we will distribute all of the shares of Asterias Series A common stock to our stockholders on a pro rata basis, other than with respect to fractional shares and shares that would otherwise be distributed to Geron stockholders residing in certain to-be-determined excluded jurisdictions, which shares, as required by the Agreement, will be sold with the net cash proceeds therefrom distributed ratably to the stockholders who would otherwise be entitled to receive such shares.

	On October 1, 2013, BioTime contributed to Asterias 8,902,077 shares of BioTime common stock, five-year warrants to purchase 8,000,000 additional shares of BioTime common stock at an exercise price of $5.00 per share, or the BioTime Warrants, minority stakes in two of BioTime’s subsidiaries and rights to use certain human embryonic stem cell lines. In addition, BioTime had previously loaned Asterias $5,000,000 in cash and the principal amount of this debt was cancelled as part of the closing of the Agreement. In consideration of BioTime’s contributions, on October 1, 2013 Asterias issued to BioTime 21,773,340 shares of Asterias Series B common stock representing 71.6% of Asterias’ outstanding common stock as a class as of that date, and three-year warrants to purchase 3,150,000 additional shares of Asterias Series B common stock at an exercise price of $5.00 per share. Upon completion of the distribution of the Asterias Series A common stock to our stockholders, Asterias is contractually obligated under the Agreement to distribute the BioTime Warrants on a pro rata basis to the holders of Asterias Series A common stock.

SUMMARY_OF_SIGNIFICANT_ACCOUNT1

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)

9 Months Ended

Sep. 30, 2013

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Basis of Presentation

Principles of Consolidation

Net Loss Per Share

Use of Estimates

Fair Value of Financial Instruments

Cash Equivalents and Marketable Securities

Fair Value of Derivatives

Revenue Recognition

Restricted Cash

Restricted cash consists of funds maintained in separate certificate of deposit accounts for specified purposes. The components of restricted cash were as follows:

September 30,

December 31,

(In thousands)

2013

2012

Certificate of deposit for unused equipment line of credit

530

Certificate of deposit for credit card purchases

265

264

795

794

Research and Development Expenses

Clinical Trial Costs

Depreciation and Amortization

Stock-Based Compensation

Three Months Ended

Nine Months Ended

September 30,

(In thousands)

2013

2012

2013

2012

Research and development

483

594

1,394

1,861

Restructuring charges

—

General and administrative

739

669

2,034

2,155

Stock-based compensation expense included in operating expenses

1,222

1,263

3,456

4,016

Stock Options

Nine Months Ended September 30,

2013

2012

Dividend yield

None

Expected volatility range

0.742 to 0.759

0.631 to 0.726

Risk-free interest rate range

0.80% to 1.81%

0.81% to 1.25%

Expected term

6 yrs

Employee Stock Purchase Plan

The fair value of employees’ purchase rights during the nine months ended September 30, 2013 and 2012 has been estimated using the Black Scholes option-pricing model with the following assumptions:

Nine Months Ended September 30,

2013

2012

Dividend yield

None

Expected volatility range

0.506 to 1.391

0.458 to 0.774

Risk-free interest rate range

0.09% to 0.21%

0.06% to 0.21%

Expected term range

6 - 12 mos

Restricted Stock Awards

Non-Employee Stock-Based Awards

SUMMARY_OF_SIGNIFICANT_ACCOUNT2

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)	9 Months Ended
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)	Sep. 30, 2013
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	'
Schedule of components of restricted cash	'

		September 30,			December 31,
	(In thousands)	2013			2012
	Certificate of deposit for unused equipment line of credit	$	530		$	530
	Certificate of deposit for credit card purchases	265			264
		$	795		$	794
Summary of allocation of stock-based compensation expense related to share-based payment awards	'


		Three Months Ended					Nine Months Ended
		September 30,					September 30,
	(In thousands)	2013			2012		2013		2012
	Research and development	$	483		$	594	$	1,394	$	1,861
	Restructuring charges	—			—		28		—
	General and administrative	739			669		2,034		2,155
	Stock-based compensation expense included in operating expenses	$	1,222		$	1,263	$	3,456	$	4,016
Schedule of assumptions used to estimate the fair value of stock options granted	'


		Nine Months Ended September 30,
		2013		2012
	Dividend yield	None		None
	Expected volatility range	0.742 to 0.759		0.631 to 0.726
	Risk-free interest rate range	0.80% to 1.81%		0.81% to 1.25%
	Expected term	6 yrs		6 yrs
Schedule of assumptions used to estimate the fair value of employee stock purchases under the Purchase Plan	'


		Nine Months Ended September 30,
		2013		2012
	Dividend yield	None		None
	Expected volatility range	0.506 to 1.391		0.458 to 0.774
	Risk-free interest rate range	0.09% to 0.21%		0.06% to 0.21%
	Expected term range	6 - 12 mos		6 - 12 mos

FAIR_VALUE_MEASUREMENTS_Tables

FAIR VALUE MEASUREMENTS (Tables)	9 Months Ended
FAIR VALUE MEASUREMENTS (Tables)	Sep. 30, 2013
FAIR VALUE MEASUREMENTS	'
Schedule of cash equivalents, restricted cash and marketable securities by security type	'
	Cash equivalents, restricted cash and marketable securities by security type at September 30, 2013 were as follows:

					Gross			Gross
		Amortized			Unrealized			Unrealized			Estimated
		Cost			Gains			Losses			Fair Value
		(In thousands)
	Included in cash and cash equivalents:
	Money market funds	$	5,997		$	—		$	—		$	5,997
	Restricted cash:
	Certificates of deposit	$	795		$	—		$	—		$	795
	Marketable securities (due in less than 1 year):
	Government-sponsored enterprise securities	$	7,319		$	1		$	—		$	7,320
	Commercial paper	15,741			9			—			15,750
	Corporate notes	33,569			—			(22		)	33,547
		$	56,629		$	10		$	(22	)	$	56,617

	Cash equivalents, restricted cash and marketable securities by security type at December 31, 2012 were as follows:

					Gross			Gross
		Amortized			Unrealized			Unrealized			Estimated
		Cost			Gains			Losses			Fair Value
		(In thousands)
	Included in cash and cash equivalents:
	Money market funds	$	15,660		$	—		$	—		$	15,660
	Corporate notes	3,136			—			(1		)	3,135
		$	18,796		$	—		$	(1	)	$	18,795
	Restricted cash:
	Certificates of deposit	$	794		$	—		$	—		$	794
	Marketable securities (due in less than 1 year):
	Government-sponsored enterprise securities	$	8,618		$	5		$	—		$	8,623
	Commercial paper	20,623			21			—			20,644
	Corporate notes	44,190			22			(7		)	44,205
		$	73,431		$	48		$	(7	)	$	73,472
Schedule of marketable securities with unrealized losses	'


		Less Than 12 Months						12 Months or Greater					Total
					Gross						Gross					Gross
		Estimated			Unrealized			Estimated			Unrealized		Estimated			Unrealized
		Fair Value			Losses			Fair Value			Losses		Fair Value			Losses
		(In thousands)
	As of September 30, 2013:
	Corporate notes (due in less than 1 year)	$	31,654		$	(22	)	$	—		$	—	$	31,654		$	(22	)

	As of December 31, 2012:
	Corporate notes (due in less than 1 year)	$	27,045		$	(8	)	$	—		$	—	$	27,045		$	(8	)

Schedule of non-employee options to purchase common stock considered as derivatives and classified as current liabilities	'


									At September 30, 2013				At December 31, 2012
									Number		Fair		Number		Fair
	Issuance	Exercise			Exercisable		Expiration		of		Value		of		Value
	Date	Price			Date		Date		Shares		(In thousands)		Shares		(In thousands)
	March 2005	$	6.39		January 2007		March 2015		284,600		$	258	284,600		$	51
Schedule of assumptions used to estimate the fair value of derivatives	'


		September 30, 2013		December 31, 2012
	Dividend yield	None		None
	Expected volatility	0.955		0.828
	Risk-free interest rate	0.33%		0.25%
	Expected term	2 yrs		2 yrs
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 September 30, 2013 and indicates the fair value category assigned.

		Fair Value Measurements at Reporting Date Using
		Quoted Prices in			Significant
		Active Markets			Other			Significant
		for Identical			Observable			Unobservable
		Assets / Liabilities			Inputs			Inputs
	(In thousands)	Level 1			Level 2			Level 3			Total
	Assets
	Money market funds (1)	$	5,997		$	—		$	—		$	5,997
	Government-sponsored enterprise securities (2)	—			7,320			—			7,320
	Commercial paper (2)	—			15,750			—			15,750
	Corporate notes (2)	—			33,547			—			33,547
	Total	$	5,997		$	56,617		$	—		$	62,614

	Liabilities
	Derivatives (3)	$	—		$	—		$	258		$	258

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

	(2) Included in current marketable securities on our condensed consolidated balance sheets.

	(3) Included in fair value of derivatives on our condensed consolidated balance sheets.
Schedule of rollforward of the balance sheet amounts for financial instruments in Level 3 category	'


					Fair Value Measurements Using Significant Unobservable Inputs (Level 3)
					Three Months Ended September 30, 2013
																			Change in
																			Unrealized Loss
					Total														Related to
					Unrealized								Transfers						Financial
		Fair Value at			Loss			Purchases					In and/or			Fair Value at			Instruments
		June 30,			Included in			and			Sales and		Out of			September 30,			Held at
	(In thousands)	2013			Earnings (1)			Issuances			Settlements		Level 3			2013			September 30, 2013 (1)
	Derivative liabilities	$	50		$	208		$	—		$	—	$	—		$	258		$	208


					Fair Value Measurements Using Significant Unobservable Inputs (Level 3)
					Nine Months Ended September 30, 2013
																			Change in
																			Unrealized Loss
					Total														Related to
					Unrealized								Transfers						Financial
		Fair Value at			Loss			Purchases					In and/or			Fair Value at			Instruments
		December 31,			Included in			and			Sales and		Out of			September 30,			Held at
	(In thousands)	2012			Earnings (1)			Issuances			Settlements		Level 3			2013			September 30, 2013 (1)
	Derivative liabilities	$	51		$	207		$	—		$	—	$	—		$	258		$	207


	(1) Reported as unrealized loss on derivatives in our condensed consolidated statements of operations.

RESTRUCTURINGS_Tables

RESTRUCTURINGS (Tables)	9 Months Ended
	Sep. 30, 2013
RESTRUCTURINGS	'
Summary of components of outstanding restructuring liability	'


	(In thousands)	Employee			Asset			Facility Related			Total
		Severance and			Write Downs			Charges
		Other Benefits
	Beginning accrual balance as of December 31, 2012	$	1,972		$	—		$	—		$	1,972
	Restructuring charges	716			200			116			1,032
	Cash payments	(2,373		)	—			(96		)	(2,469		)
	Adjustments or non-cash credits, including stock-based compensation expense	(174		)	(200		)	—			(374		)
	Ending accrual balance as of September 30, 2013	$	141		$	—		$	20		$	161

CONDENSED_CONSOLIDATED_STATEME4

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS DATA (Tables)	9 Months Ended
	Sep. 30, 2013
CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS DATA	'
Supplemental schedule of non-cash operating and investing activities	'


		Nine Months Ended
		September 30,
	(In thousands)	2013			2012
	Supplemental Operating Activities:
	Issuance of common stock for 401(k) matching contributions	$	839		$	1,361
	Issuance of common stock for services rendered to date or to be received in future periods	—			69
	Reclassification of deposits to other current assets, net	219			135
	Supplemental Investing Activities:
	Net unrealized (loss) gain on available-for-sale securities	(52		)	4

SUMMARY_OF_SIGNIFICANT_ACCOUNT3

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Net Loss Per Share	'	'	'	'
Potential dilutive securities excluded from diluted earnings (loss) per share calculation (in shares)	'	'	7,183	16,061
Marketable securities	'	'	'	'
Other-than-temporary impairment charges recorded for available-for-sale securities	$0	$0	$0	$0
Minimum	'	'	'	'
Marketable securities	'	'	'	'
Original maturity period of marketable securities	'	'	'5 months	'
Maximum	'	'	'	'
Marketable securities	'	'	'	'
Original maturity period of marketable securities	'	'	'16 months	'

SUMMARY_OF_SIGNIFICANT_ACCOUNT4

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 2) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Restricted Cash	'	'
Carrying value of restricted cash	$795	$794
Depreciation and Amortization	'	'
Estimated useful lives of assets	'4 years	'
Certificate of deposit for unused equipment line of credit	'	'
Restricted Cash	'	'
Carrying value of restricted cash	530	530
Certificate of deposit for credit card purchases	'	'
Restricted Cash	'	'
Carrying value of restricted cash	$265	$264

SUMMARY_OF_SIGNIFICANT_ACCOUNT5

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 3) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Stock-Based Compensation	'	'	'	'
Stock-based compensation expense included in operating expenses	$1,222,000	$1,263,000	$3,456,000	$4,016,000
Stock options \| Certain members of executive management team	'	'	'	'
Stock-Based Compensation	'	'	'	'
Modifications to the Post-termination exercise period	205,000	'	205,000	'
Research and development	'	'	'	'
Stock-Based Compensation	'	'	'	'
Stock-based compensation expense included in operating expenses	483,000	594,000	1,394,000	1,861,000
Restructuring charges	'	'	'	'
Stock-Based Compensation	'	'	'	'
Stock-based compensation expense included in operating expenses	'	'	28,000	'
General and administrative	'	'	'	'
Stock-Based Compensation	'	'	'	'
Stock-based compensation expense included in operating expenses	$739,000	$669,000	$2,034,000	$2,155,000

SUMMARY_OF_SIGNIFICANT_ACCOUNT6

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 4) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Assumptions used to estimate fair value of awards	'	'	'	'
Stock-based compensation expense included in operating expenses	$1,222	$1,263	$3,456	$4,016
Stock options	'	'	'	'
Assumptions used to estimate fair value of awards	'	'	'	'
Dividend yield (as a percent)	'	'	0.00%	0.00%
Expected volatility range, minimum (as a percent)	'	'	74.20%	63.10%
Expected volatility range, maximum (as a percent)	'	'	75.90%	72.60%
Risk-free interest rate range, minimum (as a percent)	'	'	0.80%	0.81%
Risk-free interest rate range, maximum (as a percent)	'	'	1.81%	1.25%
Expected term	'	'	'6 years	'6 years
Vesting period of awards	'	'	'4 years	'
Restricted stock awards	'	'	'	'
Assumptions used to estimate fair value of awards	'	'	'	'
Types of vesting schedules (in count)	'	'	3	'
Service-based restricted stock awards	'	'	'	'
Assumptions used to estimate fair value of awards	'	'	'	'
Vesting period of awards	'	'	'4 years	'
Performance-based restricted stock awards	'	'	'	'
Assumptions used to estimate fair value of awards	'	'	'	'
Vesting period of awards	'	'	'3 years	'
Stock-based compensation expense included in operating expenses	$0	$0	$0	$0
Market-based restricted stock awards	'	'	'	'
Assumptions used to estimate fair value of awards	'	'	'	'
Vesting period of awards	'	'	'3 years	'
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)	'	'	50.60%	45.80%
Expected volatility range, maximum (as a percent)	'	'	139.10%	77.40%
Risk-free interest rate range, minimum (as a percent)	'	'	0.09%	0.06%
Risk-free interest rate range, maximum (as a percent)	'	'	0.21%	0.21%
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

FAIR_VALUE_MEASUREMENTS_Detail

FAIR VALUE MEASUREMENTS (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Included in cash and cash equivalents	'	'
Amortized Cost	$5,997	$18,796
Gross Unrealized Losses	'	-1
Estimated Fair Value	5,997	18,795
Restricted cash	'	'
Amortized Cost	795	794
Estimated Fair Value	795	794
Marketable securities	'	'
Amortized Cost	56,629	73,431
Gross Unrealized Gains	10	48
Gross Unrealized Losses	-22	-7
Estimated Fair Value	56,617	73,472
Money market funds	'	'
Included in cash and cash equivalents	'	'
Amortized Cost	5,997	15,660
Estimated Fair Value	5,997	15,660
Certificates of deposit	'	'
Restricted cash	'	'
Amortized Cost	795	794
Estimated Fair Value	795	794
Government-sponsored enterprise securities	'	'
Marketable securities	'	'
Amortized Cost	7,319	8,618
Gross Unrealized Gains	1	5
Estimated Fair Value	7,320	8,623
Commercial paper	'	'
Marketable securities	'	'
Amortized Cost	15,741	20,623
Gross Unrealized Gains	9	21
Estimated Fair Value	15,750	20,644
Corporate notes	'	'
Included in cash and cash equivalents	'	'
Amortized Cost	'	3,136
Gross Unrealized Losses	'	-1
Estimated Fair Value	'	3,135
Marketable securities	'	'
Amortized Cost	33,569	44,190
Gross Unrealized Gains	'	22
Gross Unrealized Losses	-22	-7
Estimated Fair Value	$33,547	$44,205

FAIR_VALUE_MEASUREMENTS_Detail1

FAIR VALUE MEASUREMENTS (Details 2) (Corporate notes, USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Corporate notes	'	'
Marketable securities with unrealized losses	'	'
Less Than 12 Months - Estimated Fair Value	$31,654	$27,045
Less Than 12 Months - Gross Unrealized Losses	-22	-8
Total - Estimated Fair Value	31,654	27,045
Total - Gross Unrealized Losses	($22)	($8)

FAIR_VALUE_MEASUREMENTS_Detail2

FAIR VALUE MEASUREMENTS (Details 3) (USD $)	9 Months Ended	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Fair Value Measurement	'	'
Fair Value	$258	$51
Dividend yield (as a percent)	0.00%	0.00%
Expected volatility (as a percent)	95.50%	82.80%
Risk-free interest rate (as a percent)	0.33%	0.25%
Expected term	'2 years	'2 years
Non-employee options	'	'
Fair Value Measurement	'	'
Amount of reclassifications from current liabilities to stockholders' equity	0	'
Exercise Price (in dollars per share)	$6.39	'
Number of Shares	284,600	284,600
Fair Value	$258	$51

FAIR_VALUE_MEASUREMENTS_Detail3

FAIR VALUE MEASUREMENTS (Details 4) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Liabilities	'	'
Derivatives	$258	$51
Recurring basis \| Level 1	'	'
Assets	'	'
Total	5,997	'
Recurring basis \| Level 1 \| Money market funds	'	'
Assets	'	'
Total	5,997	'
Recurring basis \| Level 2	'	'
Assets	'	'
Total	56,617	'
Recurring basis \| Level 2 \| Government-sponsored enterprise securities	'	'
Assets	'	'
Total	7,320	'
Recurring basis \| Level 2 \| Commercial paper	'	'
Assets	'	'
Total	15,750	'
Recurring basis \| Level 2 \| Corporate notes	'	'
Assets	'	'
Total	33,547	'
Recurring basis \| Level 3	'	'
Liabilities	'	'
Derivatives	258	'
Recurring basis \| Total	'	'
Assets	'	'
Total	62,614	'
Liabilities	'	'
Derivatives	258	'
Recurring basis \| Total \| Money market funds	'	'
Assets	'	'
Total	5,997	'
Recurring basis \| Total \| Government-sponsored enterprise securities	'	'
Assets	'	'
Total	7,320	'
Recurring basis \| Total \| Commercial paper	'	'
Assets	'	'
Total	15,750	'
Recurring basis \| Total \| Corporate notes	'	'
Assets	'	'
Total	$33,547	'

FAIR_VALUE_MEASUREMENTS_Detail4

FAIR VALUE MEASUREMENTS (Details 5) (USD $)	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013	Sep. 30, 2013
In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012	Derivative liabilities	Derivative liabilities
Changes in Level 3 Recurring Fair Value Measurements	'	'	'	'
Fair value of derivative liabilities at the beginning of the period	$258	$51	$50	$51
Total Unrealized Loss Included in Earnings	'	'	208	207
Fair value of derivative liabilities at the end of the period	258	51	258	258
Change in Unrealized Loss Related to Financial Instruments Held at the end of the period	'	'	$208	$207

RESTRUCTURINGS_Details

RESTRUCTURINGS (Details) (USD $)

3 Months Ended

9 Months Ended

0 Months Ended

6 Months Ended

3 Months Ended

6 Months Ended

12 Months Ended

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Apr. 25, 2013

Sep. 30, 2013

Dec. 31, 2012

Jun. 30, 2013

Sep. 30, 2013

Dec. 03, 2012

Nov. 14, 2011

Employee Severance And Other Benefits

Asset Write Downs

Facility Related Charges

April 2013 Restructuring

December 2012 Restructuring

November 2011 Restructuring

position

One-time termination benefits

Asset Write Downs

Facility Related Charges

One-time termination benefits and facility-related charges

position

RESTRUCTURINGS

Number of full-time positions eliminated, inception to date

Aggregate estimated restructuring charges

$1,500,000

Expected cash payments

1,250,000

Proceeds from sales of property and equipment

1,116,000

38,000

1,000,000

Outstanding restructuring liability

Accrual balance at the beginning of the period

1,972,000

Restructuring charges

116,000

1,032,000

716,000

200,000

116,000

940,000

624,000

200,000

116,000

2,702,000

92,000

2,794,000

Stock-based compensation expense related to extension of the post-termination exercise period

28,000

Cash payments

-2,469,000

-2,373,000

-96,000

-571,000

Adjustments or non-cash credits, including stock-based compensation expense

-374,000

-174,000

-200,000

Accrual balance at the end of the period

$161,000

$141,000

$20,000

SEGMENT_INFORMATION_Details

SEGMENT INFORMATION (Details)	9 Months Ended
	Sep. 30, 2013
	item
SEGMENT INFORMATION	'
Number of operating segments	1

CONDENSED_CONSOLIDATED_STATEME5

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS DATA (Details) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Supplemental Operating Activities:	'	'
Issuance of common stock for 401(k) matching contributions	$839	$1,361
Issuance of common stock for services rendered to date or to be received in future periods	'	69
Reclassification of deposits to other current assets, net	219	135
Supplemental Investing Activities:	'	'
Net unrealized (loss) gain on available-for-sale securities	($52)	$4

SUBSEQUENT_EVENT_Details

SUBSEQUENT EVENT (Details) (Subsequent event, USD $)	0 Months Ended
	Oct. 02, 2013
	item
Asset Contribution Agreement \| BioTime Contributions \| Asterias	'
SUBSEQUENT EVENT	'
Amount of debt forgiven	$5,000,000
Shares issued	8,902,077
Term of warrants issued	'5 years
Number of warrants issued	8,000,000
Exercise price of warrants issued	$5
Number of subsidiaries for which minority interests were contributed	2
Asset Contribution Agreement \| Asterias contributions \| BioTime	'
SUBSEQUENT EVENT	'
Shares issued	21,773,340
Percentage ownership in Asterias	71.60%
Term of warrants issued	'3 years
Number of warrants issued	3,150,000
Exercise price of warrants issued	$5
Asset Contribution Agreement \| Asterias contributions \| Geron	'
SUBSEQUENT EVENT	'
Number of rulings in favor of ViaCyte, Inc. for which the entity was substituted as a party in an appeal	2
Shares issued	6,537,779
Percentage ownership in Asterias	21.40%