Immune Design 10-Q 14 May 15 2015 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	3 Months Ended
	Mar. 31, 2015	11-May-15
Document and Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	FALSE
Document Period End Date	31-Mar-15
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q1
Trading Symbol	IMDZ
Entity Registrant Name	Immune Design Corp.
Entity Central Index Key	1437786
Current Fiscal Year End Date	-19
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		19,991,782

Balance_Sheets

Balance Sheets (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Current assets:
Cash and cash equivalents	$60,230	$75,354
Accounts receivable	1,578	1,970
Inventory	27	25
Prepaid expenses	781	633
Total current assets	62,616	77,982
Property and equipment, net	481	401
Deferred offering costs	200	0
Total assets	63,297	78,383
Current liabilities:
Accounts payable	2,423	6,903
Accrued liabilities	2,506	5,001
Deferred rent, current	47	43
Total current liabilities	4,976	11,947
Other noncurrent liabilities	73	90
Commitments and contingencies:
Convertible preferred stock, $0.001 par value per share; 10,000,000 shares authorized at March 31, 2015 (unaudited) and December 31, 2014; zero shares issued and outstanding at March 31, 2015 (unaudited) and December 31, 2014; liquidation preference of zero at March 31, 2015 (unaudited) and December 31, 2014	0	0
Stockholders’ equity:
Common stock, $0.001 par value per share; 100,000,000 shares authorized at March 31, 2015(unaudited) and December 31, 2014; 16,979,688 and 16,878,817 shares issued and outstanding at March 31, 2015 (unaudited) and December 31, 2014, respectively	17	17
Additional paid-in capital	158,400	157,092
Accumulated deficit	-100,169	-90,763
Total stockholders’ equity	58,248	66,346
Total liabilities, convertible preferred stock and stockholders’ equity	$63,297	$78,383

Balance_Sheets_Parenthetical

Balance Sheets (Parenthetical) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, except Share data, unless otherwise specified
Convertible preferred stock
Par value per share (in USD per share)	$0.00	$0.00
Shares issued (in shares)	0	0
Shares outstanding (in shares)	0	0
Shares authorized (in shares)	10,000,000	10,000,000
Liquidation preference	$0	$0
Common stock
Par value per share (in USD per share)	$0.00	$0.00
Shares issued (in shares)	16,979,688	16,878,817
Shares outstanding (in shares)	16,979,688	16,878,817
Shares authorized (in shares)	100,000,000	100,000,000

Statements_of_Operations

Statements of Operations (USD $)	3 Months Ended
In Thousands, except Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Revenues:
Product sales	$89	$25
Other, net	1,849	0
Total revenues	1,938	25
Operating expenses:
Cost of product sales	79	14
Research and development	7,463	4,078
General and administrative	3,802	1,446
Total operating expenses	11,344	5,538
Loss from operations	-9,406	-5,513
Interest and other income	0	1
Change in fair value of convertible preferred stock warrant liability	0	-2,711
Net loss attributable to common stockholders	($9,406)	($8,223)
Earnings Per Share
Basic and diluted net loss per share attributable to common stockholders (in USD per share)	($0.56)	($22.25)
Weighted Average Number of Shares Outstanding, Diluted
Weighted-average shares used to compute basic and diluted net loss per share attributable to common stockholders (in shares)	16,944,871	369,656

Statements_of_Cash_Flows

Statements of Cash Flows (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Operating activities
Net loss	($9,406)	($8,223)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	52	61
Stock-based compensation expense	1,231	187
Revaluation of convertible preferred stock warrant liability	0	2,711
Changes in operating assets and liabilities:
Accounts receivable	392	75
Inventory	-2	3
Prepaid expenses	-148	-145
Accounts payable	-4,480	71
Accrued liabilities	-2,571	121
Deferred rent	-9	-2
Net cash used in operating activities	-14,941	-5,141
Investing activities
Purchases of property and equipment	-132	-59
Net cash used in investing activities	-132	-59
Financing activities
Deferred offering costs	-128	-171
Proceeds from exercise of stock options	77	0
Net cash used in financing activities	-51	-171
Net decrease in cash and cash equivalents	-15,124	-5,371
Cash and cash equivalents, beginning of period	75,354	30,387
Cash and cash equivalents, end of period	60,230	25,016
Supplemental cash flow information
Accrual of offering costs	$72	$167

Description_of_the_Business

Description of the Business	3 Months Ended
	Mar. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of the Business	Description of the Business
	Immune Design Corp. (we, us or our) is a clinical-stage immunotherapy company with next-generation in vivo approaches designed to enable the body’s immune system to fight disease. We have engineered our technologies to activate the immune system’s natural ability to create tumor-specific cytotoxic T cells (CTLs) to fight cancer. We are developing multiple product candidates from our two discovery platforms, ZVex™ and GLAAS™. Our product candidates, CMB305, LV305 and G100, utilize multiple immuno-oncology approaches and are in Phase 1 clinical trials. CMB305 is a prime-boost approach, in which LV305 from our ZVex platform is dosed sequentially with G305 from our GLAAS platform. Although we plan to focus our development efforts on CMB305 and G100, we plan to conduct a small exploratory trial to compare CMB305 and LV305 in the same tumor types. After reviewing those data, we may elect to separately develop LV305.
	We were incorporated in February 2008 in the State of Delaware. Our operations are headquartered in Seattle, Washington, and we have additional facilities in South San Francisco, California.

Summary_of_Significant_Account

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2015
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies
	Basis of Presentation and Use of Estimates
	The accompanying financial statements have been prepared in accordance with U.S. generally accepted accounting principles (GAAP). To conform with GAAP, the preparation of our financial statements requires management to make judgments, assumptions, and estimates that affect the amounts reported in our financial statements and accompanying notes. Estimates are used for, but not limited to, accruals for clinical trial activity, other accrued liabilities, and assumptions used in determining stock-based compensation expenses and convertible preferred stock warrant liability. We base our estimates on historical experience and on various other assumptions that we believe to be reasonable. Actual results could differ materially from those estimates.
	Unaudited Interim Financial Information
	The accompanying unaudited financial statements as of March 31, 2015 and for the three months ended March 31, 2015 and 2014 and the related interim information contained within the notes to the financial statements are unaudited. The unaudited interim financial statements have been prepared on the same basis as the audited financial statements and in the opinion of management, reflect all normal recurring adjustments necessary for a fair statement of our financial position for the interim periods presented. The results of operations for the three months ended March 31, 2015 are not necessarily indicative of the results to be expected for the year ended December 31, 2015 or for other future interim periods or years.
	The accompanying unaudited financial statements should be read in conjunction with the audited financial statements for the year ended December 31, 2014 included in our Annual Report on Form 10-K for the year ended December 31, 2014, filed with the Securities and Exchange Commission (SEC).
	Segments
	We operate in one segment and use cash flow as the primary measure to manage our business and do not segment the business for internal reporting or decision-making purposes.
	Reverse Stock Split
	On July 14, 2014, we filed an amendment to our amended and restated certificate of incorporation, effecting a 1-for-8.175 reverse stock split. All issued and outstanding stock and per share amounts contained in our financial statements have been retroactively adjusted to reflect this reverse stock split for all periods presented.
	Offering Costs
	Offering costs represent legal, accounting and other direct costs related to our efforts to raise capital through our follow-on public offering in April 2015 and for our initial public offering (IPO) in July 2014. These costs were deferred until completion of the follow-on public offering and IPO, respectively, at which time they were reclassified to additional paid-in capital as a reduction of the proceeds.
	Comprehensive Loss
	Comprehensive loss is comprised of net loss and certain changes in equity that are excluded from net loss. There was no difference between comprehensive loss and net loss for the three months ended March 31, 2015 and 2014.
	Revenue Recognition
	We derive our revenue from collaboration and licensing agreements and the sale of products associated with material transfer, collaboration and supply agreements.
	Licensing fees are recognized when the amounts are earned and determinable during the applicable period. We recognize up-front nonrefundable license fees when due under contractual agreements and when we do not have a continuing obligation to provide services related to the agreement. Revenue associated with nonrefundable up-front license fees under arrangements where the license fees and research and development activities cannot be accounted for as separate units of accounting is deferred and recognized as revenue on a straight-line basis over the expected term of our continued involvement in the research and development process. Revenues from the achievement of research and development milestones, if deemed substantive, are recognized as revenue when the milestones are achieved, and the milestone payments are due and collectible. If not deemed substantive, we recognize such milestones as revenue on a straight-line basis over the remaining expected term of continued involvement in the research and development process.
	Milestones are considered substantive if all of the following conditions are met: (1) the milestone is nonrefundable, (2) achievement of the milestone was not reasonably assured at the inception of the arrangement, (3) substantive effort is involved to achieve the milestone, and (4) the amount of the milestone appears reasonable in relation to the effort expended, the other milestones in the arrangement and the related risk associated with the achievement of the milestone and any ongoing research and development or other services are priced at fair value. Payments received in advance of work performed are recorded as unearned revenue.
	Certain agreements from which we derive our revenue include multiple deliverables. We recognize the revenue for each deliverable at fair value determined to be the estimated selling price in cases when neither vendor specific objective evidence nor third-party evidence is available.
	Revenue is recognized when all of the following criteria are met: (1) persuasive evidence of an arrangement exists, (2) delivery has occurred or services have been rendered, (3) the price to the customer is fixed or determinable and (4) collectability is reasonably assured. The evaluation of these revenue recognition criteria requires significant management judgment. For instance, we use judgment to assess collectability based on factors such as the customer’s creditworthiness and past collection history, if applicable. If we determine that collection of a payment is not reasonably assured, revenue recognition is deferred until receipt of payment. We also use judgment to assess whether a price is fixed or determinable including, but not limited to, reviewing contractual terms and conditions related to payment terms.
	Revenue from product sales of glucopyranosyl lipid A (GLA) is recognized when the risk of loss has passed to the customer or deferred until such time that risk of loss has passed. All revenues associated from the sale of GLA products supplied by us are reported under product sales with the applicable costs reported under cost of product sales. Product sales consist of the direct costs associated with the manufacture and formulation of GLA, including costs to purchase raw materials, third-party contract manufacturing costs, assay testing and ongoing product stability testing.
	Recent Accounting Pronouncements
	In May 2014, the Financial Accounting Standards Board (FASB), issued Accounting Standards Update (ASU) No. 2014-09, related to the recognition of revenue. ASU 2014-09 requires entities to recognize revenue through the application of a five step model, which includes identification of the contract, identification of the performance obligations, determination of the transaction price, allocation of the transaction price to the performance obligations, and recognition of revenue as the entity satisfies the performance obligations. ASU 2014-09 is effective retrospectively for annual or interim reporting periods beginning after December 15, 2016, with early application not permitted. We are evaluating the guidance to determine the potential impact on our results of operations, financial condition, cash flows, and financial statement disclosures.
	In August 2014, FASB issued ASU 2014-15, related to an entity’s ability to continue as a going concern. ASU 2014-15 requires an entity's management to evaluate whether there are conditions or events that raise substantial doubt about the entity's ability to continue as a going concern within one year after the date that the financial statements are issued. Public entities are required to apply ASU 2014-15 for annual reporting periods ending after December 15, 2016, and interim periods thereafter. Early application is permitted. We are evaluating the guidance to determine the potential impact on our results of operations, financial condition, cash flows, and financial statement disclosures.

Net_Loss_Per_Share

Net Loss Per Share	3 Months Ended
	Mar. 31, 2015
Earnings Per Share [Abstract]
Net Loss Per Share	Net Loss Per Share
	Basic net loss per share is computed by dividing net loss by the weighted-average number of common shares outstanding during the period. Because of net losses recognized in each period, potential common shares issuable upon the exercise of outstanding stock options and warrants and the conversion of preferred shares in the IPO into common shares have not been reflected in the calculation of diluted net loss per share due to the anti-dilutive effect. Diluted net loss per share, therefore, does not differ from basic net loss per share.
	The common stock equivalents issuable upon the conversion or exercise of the following dilutive securities has been excluded from the computation of diluted net loss per share attributable to common stockholders calculation because their effect would have been antidilutive for the periods presented:
		March 31,
		2015	2014
		(unaudited)
	Convertible preferred stock	—	9,769,422
	Options to purchase common stock	2,308,886	1,454,283
	Warrants to purchase convertible preferred stock	—	1,975,532
	Total outstanding shares of common stock equivalents	2,308,886	13,199,237

Fair_Value_of_Financial_Instru

Fair Value of Financial Instruments	3 Months Ended
	Mar. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	Fair Value of Financial Instruments
	We measure and record cash and cash equivalents and convertible preferred stock warrant liabilities at fair value in the accompanying financial statements. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability, or an exit price, in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. The three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value, is as follows:
	Level 1: Quoted prices in active markets for identical assets or liabilities.
	Level 2: Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities, quoted prices in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.
	Level 3: Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities.
	Level 1 securities consist of highly liquid money market funds. The fair value of Level 1 assets has been determined using quoted prices in active markets for identical assets.
	The following table summarizes our financial assets and liabilities measured at fair value on a recurring basis (in thousands):
		31-Mar-15
		(unaudited)
	Assets:	LEVEL 1		LEVEL 2		LEVEL 3		TOTAL
	Money market funds	$	59,598	$	—	$	—	$	59,598
		31-Dec-14
	Assets:	LEVEL 1		LEVEL 2		LEVEL 3		TOTAL
	Money market funds	$	73,098	$	—	$	—	$	73,098

Inventory

Inventory	3 Months Ended
	Mar. 31, 2015
Inventory Disclosure [Abstract]
Inventory	Inventory
	Inventory consists of the following (in thousands):
		March 31,		December 31,
		2015		2014
		(unaudited)
	Work in process	5		—
	Finished goods	22		25
	Total inventory	$	27	$	25

Accrued_Liabilities

Accrued Liabilities	3 Months Ended
	Mar. 31, 2015
Payables and Accruals [Abstract]
Accrued Liabilities	Accrued Liabilities
	Accrued liabilities consist of the following (in thousands):
		March 31,		December 31,
		2015		2014
		(unaudited)
	Research and development services	$	1,438	$	1,845
	Legal and professional services	544		1,253
	Employee compensation	299		1,379
	Unearned revenue	225		524
	Total accrued liabilities	$	2,506	$	5,001

Commitments_and_Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies
	Operating Leases
	We lease our lab and office space under an operating lease in Seattle, Washington. The lease commenced in February 2013 and continues through November 2016, with an option to extend the term for an additional month.
	We also lease office space under an operating lease in South San Francisco, California. The lease commenced in January 2015 and continues through January 2020, with an option to extend for an additional five years. In connection with the lease, we were required to provide a $121,000 letter of credit as a security deposit. As of March 31, 2015, no funds had been drawn on the letter of credit.
	The terms of these leases provide for rental payments on a monthly basis and on a graduated scale. We recognize rent expense on a straight-line basis over the lease periods and accrue for rent expense incurred but not paid. As of March 31, 2015, the remaining aggregate non-cancelable rent payable under our leases is $2.4 million.
	Contingencies
	We are also contingently obligated to pay any potential future milestone payments to third parties as part of certain collaboration and licensing agreements, which could total up to $2.4 million in aggregate payments for the first licensed GLA product we develop, up to $1.3 million in aggregate payments for each subsequent licensed GLA product we develop and up to $1.9 million in aggregate payments for the ZVex products we develop. We also have potential future royalty payments we may be required to make under our licensing agreements as described in Note 9.
	Payments under these agreements are uncertain due to the occurrence of the events requiring payment under these agreements, including our share of potential future milestone and royalty payments. These payments generally become due and payable only upon achievement of certain clinical development, regulatory or commercial milestones.

Series_C_Convertible_Preferred

Series C Convertible Preferred Stock Warrant Liability	3 Months Ended
	Mar. 31, 2015
Other Liabilities Disclosure [Abstract]
Series C Convertible Preferred Stock Warrant Liability	Series C Convertible Preferred Stock Warrant Liability
	In October 2013, in connection with the issuance of our Series C convertible preferred stock, we issued fully exercisable warrants for the purchase of 1,975,532 shares of our Series C convertible preferred stock at an exercise price of $8.175 per share. In July 2014, immediately prior to the closing of the IPO, warrants representing 996,940 shares of common stock were exercised for $8.1 million in cash and warrants representing 978,592 shares of common stock were automatically net exercised for a total of 311,923 shares of common stock. Upon exercise of the warrants, the convertible preferred stock warrant liability was reclassified to stockholders' equity. For the three months ended March 31, 2014, we recorded a $2.7 million non-operating loss on our statement of operations related to the change in fair value of the preferred stock warrant liability.

License_and_Collaboration_Agre

License and Collaboration Agreements	3 Months Ended
	Mar. 31, 2015
Research and Development [Abstract]
License and Collaboration Agreements	License and Collaboration Agreements
	Licenses Granted
	In August 2014, we entered into an agreement with Sanofi under which we granted Sanofi an exclusive license for use of our GLAAS platform to discover, develop and commercialize products to treat a selected food allergy. Upon execution of the agreement, we received a $3.5 million upfront payment, recognized as revenue during the third quarter of 2014. The agreement provides for additional payments of up to $168.0 million based upon the attainment of certain development and commercialization milestones, and tiered royalties on sales of approved products. Sanofi may terminate the agreement at any time upon six months' written notice.
	In October 2010, we entered into three separate license agreements with MedImmune, LLC (MedImmune) pursuant to which we granted MedImmune a worldwide, sublicensable, exclusive license to use GLA to develop and sell vaccines in three different infectious disease indications. Two of the three agreements remain in full force and effect, and the rights granted under the third have returned to us. Under the license agreements, MedImmune is obligated to use commercially reasonable efforts to develop and obtain regulatory approval for a licensed product in certain markets, and to market and sell licensed products in any country where it obtains regulatory approval.In 2010, MedImmune paid us upfront payments under the license agreements. Under each license agreement, MedImmune is obligated to make additional payments based on achievement of certain development, regulatory, and commercial milestones for the licensed indication. MedImmune is also obligated to pay us a low double-digit percentage share of non-royalty payments that it receives from sublicensees and a mid single-digit percentage royalty payment on net sales of licensed products, which royalty is subject to reduction under certain circumstances. Through March 31, 2015, MedImmune has paid us an aggregate of $5.5 million under the license agreements. Under each license agreement, MedImmune is obligated to make additional aggregate payments of $62.9 million to $75.0 million, depending on the infectious disease indication, and the achievement of certain development, regulatory and commercial milestones for the licensed indication.
	Licenses Acquired
	In July 2008, we licensed certain rights to research, develop, and commercialize GLA from the Infectious Disease Research Institute (IDRI) and amended the agreement in 2010. We paid an upfront fee and issued shares of our common stock valued at $59,000 for the license. We recorded the upfront cash payment and the fair value of the common stock as research and development expense in 2008, as the licensed rights had no alternative future use.
	In addition, we agreed to pay certain fees in the future if we should elect to continue development of the applicable technologies, including payments upon achievement of certain development and commercialization milestones and royalty payments of a single-digit percentage of net sales, if and when commercialized; however, we may terminate our development program at any time without obligation to IDRI. Under our license agreement with IDRI, we are obligated to share with IDRI a percentage of payments received from third-party licensees.
	Through March 31, 2015, we have paid IDRI an aggregate of $1.9 million in upfront fees, milestone payments and sublicense revenue related to our sublicensees. We expensed these amounts to research and development expense, as the rights had no alternative future use. We are obligated to pay IDRI up to $2.4 million in additional payments based on the achievement of certain developmental and regulatory milestones for the first GLA product, and up to 1.3 million in additional payments based on the achievement of certain developmental and regulatory milestones for each subsequent GLA product.
	In 2009, we licensed certain patent rights directed to the production of dendritic cell-targeted therapeutic and prophylactic immunization strategies from the California Institute of Technology (Caltech) in exchange for shares of our common stock valued at $25,000. We make annual minimum royalty payments under the license. In addition, we agreed to pay certain fees in the future, including milestone payments upon achievement of certain development and commercialization milestones and royalty payments on net sales in the low single-digit percentage, if and when commercialized, if we should elect to continue development of the related technology; however, we may terminate our development program at any time without further obligation to Caltech. In addition, we are required to pay Caltech up to an aggregate of $1.6 million in additional payments upon the achievement of certain regulatory and sales milestones.
	Collaborations
	In October 2014, we entered into a collaboration with Sanofi Pasteur for the development of a Herpes Simplex Virus immune therapy. Sanofi Pasteur and Immune Design will each contribute product candidates to the collaboration: Sanofi Pasteur will contribute HSV-529, a clinical-stage replication-defective HSV vaccine product candidate, and Immune Design will contribute G103, our preclinical trivalent vaccine product candidate. The collaboration will explore the potential of various combinations of agents, including leveraging Immune Design's GLAAS platform, with the goal to select the best potential immune therapy for patients. Each company will develop the products jointly through Phase 2 clinical trials, at which point Sanofi Pasteur intends to continue development of the most promising candidate and be responsible for commercialization. Sanofi Pasteur will bear the costs of all preclinical and clinical development, with Immune Design providing a specific formulation of GLA from the GLAAS platform at its cost through Phase 2 studies. Immune Design will be eligible to receive future milestone and royalty payments on any product developed from the collaboration. We recognize funding from collaborative research and development efforts as revenue as we perform or deliver the related services in accordance with contract terms as long as we will receive payment for such services upon standard payment terms. The costs of the related services performed are recorded as research and development expenses on the statement of operations. For the three months ended March 31, 2015, we recognized $1.8 million in revenue under this collaboration arrangement. As of March 31, 2015, we have an outstanding receivable of $1.5 million and $193,000 recorded as unearned revenue under this collaboration agreement.

Stockholders_Equity

Stockholders' Equity	3 Months Ended
	Mar. 31, 2015
Equity [Abstract]
Stockholders' Equity	Stockholders’ Equity
	Common Stock
	We had 16,979,688 and 16,878,817 shares of common stock outstanding as of March 31, 2015 and December 31, 2014, respectively. Shares of common stock reserved for future issuance were as follows:
			March 31,			December 31,
			2015			2014
			(unaudited)
	Shares to be issued under the employee stock purchase plan		324,008			155,220
	Shares to be issued upon exercise of outstanding stock options		2,308,886			1,907,091
	Shares available for future stock option grants		1,471,553			1,274,067
	Shares of common stock reserved for future issuance		4,104,447			3,336,378
	Equity Incentive Plans
	In April 2014, our board of directors adopted, and in July 2014 our stockholders approved, the 2014 Employee Stock Purchase Plan (2014 ESPP). Upon the approval of the 2014 ESPP, 155,220 shares of our common stock were reserved for issuance. The initial offering period has been set and will begin on April 1, 2015 and end on June 30, 2015. As of March 31, 2015, no shares have been purchased under the plan.
	The total number of shares of common stock available for issuance under the 2014 ESPP will automatically increase annually on January 1 by (i) the lesser of 1% of the total number of shares of our common stock issued and outstanding as of December 31 of the immediately preceding year or (ii) 200,000 shares. On January 1, 2015, in accordance with the 2014 ESPP annual increase provisions, the authorized shares increased by 168,788 shares.
	In 2008, we adopted the 2008 Equity Incentive Plan (2008 Plan) for eligible employees, officers, directors, and consultants, which provides for the grant of incentive and non-statutory stock options, restricted stock awards, restructured stock unit awards grant, and stock appreciation rights. The terms of the stock awards, including vesting requirements, are determined by the board of directors, subject to the provisions of the 2008 Plan.
	In April 2014, our board of directors adopted, and in July 2014 our stockholders approved, the 2014 Omnibus Incentive Plan (2014 Plan) which provides for the granting of certain awards to eligible employees, officers, directors and consultants. Upon approval of the 2014 Plan by the stockholders in July 2014, 1,400,000 shares of our common stock were reserved for issuance under the 2014 Plan and we ceased granting stock awards under the 2008 Plan. All shares of common stock subject to awards under the 2008 Plan that expire, terminate, or are otherwise surrendered, canceled, forfeited or repurchased without having been fully exercised or resulting in the issuance of common stock become available for issuance under the 2014 Plan.
	The total number of shares of common stock available for issuance under the 2014 Plan will automatically increase annually on January 1 by 4% of the total number of shares of our common stock issued and outstanding as of December 31 of the immediately preceding year. On January 1, 2015, in accordance with the 2014 Plan and annual increase provisions, the authorized shares increased by 675,152 shares.
	Stock options granted under the 2008 Plan and 2014 Plan generally vest over four years and vested options are exercisable until ten years after the date of grant. Vesting of certain employee options may be accelerated in the event of a change in control of our company. We grant stock options under the 2014 Plan with exercise prices equal to the fair value of our common stock on the date of grant. There were a total of 1,471,553 shares of common stock authorized under the 2014 Plan as of March 31, 2015.
	Stock Option Activity
	Summary stock option information is as follows:
			OPTIONS			WEIGHTED-			WEIGHTED-	AGGREGATE
			OUTSTANDING			AVERAGE			AVERAGE	INTRINSIC
						EXERCISE			REMAINING	VALUE
						PRICE			CONTRACT	(in thousands)
									TERM
									(in years)
	Outstanding at December 31, 2014		1,907,091			$	4.16		8.16	$	50,847
	Granted (unaudited)		528,660			$	30.49
	Exercised (unaudited)		(100,871	)		$	0.77
	Canceled (unaudited)		(25,994	)		$	24.94
	Outstanding at March 31, 2015 (unaudited)		2,308,886			$	10.07		8.45	$	30,802
	Vested and expected to vest after March 31, 2015 (unaudited)		2,139,528			$	9.58		8.38	$	29,289
	Exercisable as of March 31, 2015 (unaudited)		780,865			$	1.34		7	$	15,440
	As of March 31, 2015, there was $13.9 million of total unrecognized stock-based compensation expense related to nonvested stock options that is expected to be recognized over a weighted-average period of 3.3 years. The total intrinsic value of options exercised during the three months ended March 31, 2015 and 2014 was $2.6 million and $0, respectively.
	Stock-Based Compensation Expense
	Employee stock-based compensation expense recognized was calculated based on awards ultimately expected to vest and has been reduced for estimated forfeitures. Forfeitures are estimated at the time of grant and revised, as necessary, in subsequent periods if actual forfeitures differ from those estimates. Total stock-based compensation expense recognized in our statements of operations is as follows (in thousands):
			Three Months Ended March 31,
			2015				2014
			(unaudited)
	Employee:
	Research and development		$	402			$	51
	General and administrative		794				86
	Non-Employee:
	Research and development		35				50
	Total stock-based compensation expense		$	1,231			$	187
	We use the Black-Scholes option pricing model to estimate the fair value of stock options at the grant date. The Black-Scholes option pricing model requires us to make certain estimates and assumptions, including assumptions related to the expected price volatility of our stock, the period during which the options will be outstanding, the rate of return on risk-free investments and the expected dividend yield of our stock.
	To estimate the fair value of our common stock prior to our IPO, our board of directors periodically determined the per share fair value of our common stock at various dates using valuations performed in accordance with the guidance outlined in the American Institute of Certified Public Accountants Practice Aid, Valuation of Privately-Held Company Equity Securities Issued as Compensation. We performed these valuations contemporaneously as of December 31, 2012, October 16, 2013 and March 31, 2014. For financial reporting purposes, we also performed a retrospective valuation on December 31, 2013. Upon the completion of our IPO, the fair value of our common stock has been determined by the trading value of our common stock on NASDAQ.
	The fair values of stock options granted to employees were calculated using the following assumptions:
			Three Months Ended March 31,
			2015		2014
			(unaudited)
	Weighted-average estimated fair value		$22.58		*
	Risk-free interest rate (1)		1.50% - 1.64%		*
	Expected term of options (in years) (2)		5.50 - 6.08		*
	Expected stock price volatility (3)		82% - 91%		*
	Expected dividend yield (4)		—		*
	* No options were granted to employees during the three months ended March 31, 2014.
	-1	The risk-free interest rate assumption was based on zero-coupon U.S. Treasury instruments that had terms consistent with the expected term of our stock option grants.
	-2	We used the “simplified method” for options to determine the expected term of our stock option grants. Under this approach, the weighted-average expected life is presumed to be the average of the vesting term and the contractual term of the option.
	-3	Volatility is a measure of the amount by which a financial variable, such as share price, has fluctuated or is expected to fluctuate during a period. We analyzed the stock price volatility of companies at a similar stage of development to estimate expected volatility of our stock price.
	-4	We have never declared or paid cash dividends and do not presently plan to pay cash dividends in the foreseeable future.

Legal_Proceedings

Legal Proceedings	3 Months Ended
	Mar. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Legal Proceedings	Legal Proceedings
	TheraVectys SA v. Immune Design Corp.
	In October 2013, TheraVectys SA, or TVS, a French biotechnology company, filed a complaint against us in the United States District Court for the District of Delaware. TVS alleged that it had entered into a contractual relationship with Henogen SA, or Henogen, in 2010 with respect to the production of lentiviral vector vaccines for TVS.  Henogen is a contract manufacturing organization with which we contracted for the manufacture of our LV305 product candidate. TVS alleged that its contractual relationship with Henogen contained an exclusivity provision limiting Henogen’s ability to participate in the manufacturing process of a vaccine based on lentiviral DNA Flap vectors for third parties, as well as a provision preventing Henogen from sharing or using certain TVS confidential technology for manufacturing processes developed by TVS with or for the benefit of others. TVS alleged that we entered into a contractual relationship with Henogen in 2012 to manufacture lentiviral vectors for vaccines, which TVS contends interfered with its contract with Henogen and resulted in the use of certain TVS confidential information and trade secrets. The complaint asserted three counts for relief: tortious interference with contractual relationship, unfair competition and misappropriation of trade secrets. TVS did not specify its claimed damages, other than to assert that they exceed $75,000. TVS also requested in its complaint injunctive relief enjoining us from importing, receiving possessing or using lentiviral vector vaccines developed or produced by Henogen, but never filed a motion seeking injunctive relief. The parties entered into several stipulations extending the deadline for us to respond to the complaint. On or about April 7, 2014, TVS filed a Notice of Voluntary Dismissal without prejudice of this lawsuit.
	On or about July 24, 2014, shortly after our Registration Statement on Form S-1 was declared effective by the SEC for our initial public offering, TVS filed a new complaint against us in the Chancery Court of the State of Delaware, alleging facts substantially similar to the prior complaint. In addition, the complaint further alleges that we obtained shipments of lentiviral vectors for vaccines from Henogen and are conducting clinical trials with these lentiviral vectors. The complaint asserts four counts for relief: tortious interference with contractual relationship, unfair competition, misappropriation of trade secrets, and unjust enrichment; claimed damages were not specified. The complaint also requested injunctive relief enjoining us from using lentiviral vectors developed or produced by Henogen, using any other materials or information obtained by Henogen, and citing to the FDA or otherwise relying on any clinical trials using lentiviral vector vaccines developed or produced by Henogen.
	On or about July 24, 2014, TVS also filed a motion for expedited proceedings in support of an anticipated motion for preliminary injunction. On August 8, 2014 the court granted TVS’ motion for expedited proceedings and set a hearing date in mid-November 2014 for TVS’ anticipated motion for preliminary injunction. In September 2014, TVS filed a motion to postpone the hearing date and delay the proceedings it previously sought to expedite. The court granted the motion and set a new date for the hearing.  On or about December 15, 2014, TVS filed a motion for a preliminary injunction seeking, among other things, to enjoin us from making any use of lentiviral vectors pending final resolution of the litigation.  A hearing was held on TVS’s motion in January 2015.
	By order dated March 9, 2015, the Chancery Court denied TVS’ motion for a preliminary injunction. The court has not yet made any final determination on the merits of the lawsuit, which will be determined at a full trial. A trial date has not yet been set. We intend to continue to vigorously defend this lawsuit.

Subsequent_Events

Subsequent Events	3 Months Ended
	Mar. 31, 2015
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events
	Follow-On Public Offering
	In April 2015, we closed an underwritten public offering of 3,000,000 shares of our common stock and received net proceeds of $74.2 million, after underwriting discounts and commissions and estimated offering expenses.

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2015
Accounting Policies [Abstract]
Basis of Presentation and Use of Estimates	Basis of Presentation and Use of Estimates
	The accompanying financial statements have been prepared in accordance with U.S. generally accepted accounting principles (GAAP). To conform with GAAP, the preparation of our financial statements requires management to make judgments, assumptions, and estimates that affect the amounts reported in our financial statements and accompanying notes. Estimates are used for, but not limited to, accruals for clinical trial activity, other accrued liabilities, and assumptions used in determining stock-based compensation expenses and convertible preferred stock warrant liability. We base our estimates on historical experience and on various other assumptions that we believe to be reasonable. Actual results could differ materially from those estimates.
Segments	Segments
	We operate in one segment and use cash flow as the primary measure to manage our business and do not segment the business for internal reporting or decision-making purposes.
Reverse Stock Split	Reverse Stock Split
	On July 14, 2014, we filed an amendment to our amended and restated certificate of incorporation, effecting a 1-for-8.175 reverse stock split. All issued and outstanding stock and per share amounts contained in our financial statements have been retroactively adjusted to reflect this reverse stock split for all periods presented.
Offering Costs	Offering Costs
	Offering costs represent legal, accounting and other direct costs related to our efforts to raise capital through our follow-on public offering in April 2015 and for our initial public offering (IPO) in July 2014. These costs were deferred until completion of the follow-on public offering and IPO, respectively, at which time they were reclassified to additional paid-in capital as a reduction of the proceeds.
Comprehensive Loss	Comprehensive Loss
	Comprehensive loss is comprised of net loss and certain changes in equity that are excluded from net loss. There was no difference between comprehensive loss and net loss for the three months ended March 31, 2015 and 2014.
Revenue Recognition	Revenue Recognition
	We derive our revenue from collaboration and licensing agreements and the sale of products associated with material transfer, collaboration and supply agreements.
	Licensing fees are recognized when the amounts are earned and determinable during the applicable period. We recognize up-front nonrefundable license fees when due under contractual agreements and when we do not have a continuing obligation to provide services related to the agreement. Revenue associated with nonrefundable up-front license fees under arrangements where the license fees and research and development activities cannot be accounted for as separate units of accounting is deferred and recognized as revenue on a straight-line basis over the expected term of our continued involvement in the research and development process. Revenues from the achievement of research and development milestones, if deemed substantive, are recognized as revenue when the milestones are achieved, and the milestone payments are due and collectible. If not deemed substantive, we recognize such milestones as revenue on a straight-line basis over the remaining expected term of continued involvement in the research and development process.
	Milestones are considered substantive if all of the following conditions are met: (1) the milestone is nonrefundable, (2) achievement of the milestone was not reasonably assured at the inception of the arrangement, (3) substantive effort is involved to achieve the milestone, and (4) the amount of the milestone appears reasonable in relation to the effort expended, the other milestones in the arrangement and the related risk associated with the achievement of the milestone and any ongoing research and development or other services are priced at fair value. Payments received in advance of work performed are recorded as unearned revenue.
	Certain agreements from which we derive our revenue include multiple deliverables. We recognize the revenue for each deliverable at fair value determined to be the estimated selling price in cases when neither vendor specific objective evidence nor third-party evidence is available.
	Revenue is recognized when all of the following criteria are met: (1) persuasive evidence of an arrangement exists, (2) delivery has occurred or services have been rendered, (3) the price to the customer is fixed or determinable and (4) collectability is reasonably assured. The evaluation of these revenue recognition criteria requires significant management judgment. For instance, we use judgment to assess collectability based on factors such as the customer’s creditworthiness and past collection history, if applicable. If we determine that collection of a payment is not reasonably assured, revenue recognition is deferred until receipt of payment. We also use judgment to assess whether a price is fixed or determinable including, but not limited to, reviewing contractual terms and conditions related to payment terms.
	Revenue from product sales of glucopyranosyl lipid A (GLA) is recognized when the risk of loss has passed to the customer or deferred until such time that risk of loss has passed. All revenues associated from the sale of GLA products supplied by us are reported under product sales with the applicable costs reported under cost of product sales. Product sales consist of the direct costs associated with the manufacture and formulation of GLA, including costs to purchase raw materials, third-party contract manufacturing costs, assay testing and ongoing product stability testing.
Recent Accounting Pronouncements	Recent Accounting Pronouncements
	In May 2014, the Financial Accounting Standards Board (FASB), issued Accounting Standards Update (ASU) No. 2014-09, related to the recognition of revenue. ASU 2014-09 requires entities to recognize revenue through the application of a five step model, which includes identification of the contract, identification of the performance obligations, determination of the transaction price, allocation of the transaction price to the performance obligations, and recognition of revenue as the entity satisfies the performance obligations. ASU 2014-09 is effective retrospectively for annual or interim reporting periods beginning after December 15, 2016, with early application not permitted. We are evaluating the guidance to determine the potential impact on our results of operations, financial condition, cash flows, and financial statement disclosures.
	In August 2014, FASB issued ASU 2014-15, related to an entity’s ability to continue as a going concern. ASU 2014-15 requires an entity's management to evaluate whether there are conditions or events that raise substantial doubt about the entity's ability to continue as a going concern within one year after the date that the financial statements are issued. Public entities are required to apply ASU 2014-15 for annual reporting periods ending after December 15, 2016, and interim periods thereafter. Early application is permitted. We are evaluating the guidance to determine the potential impact on our results of operations, financial condition, cash flows, and financial statement disclosures.

Net_Loss_Per_Share_Tables

Net Loss Per Share (Tables)	3 Months Ended
	Mar. 31, 2015
Earnings Per Share [Abstract]
Common Stock Issuable Upon the Conversion or Exercise of Dilutive Securities Excluded from Diluted Net Loss Per Share Attributable to Common Stockholders	The common stock equivalents issuable upon the conversion or exercise of the following dilutive securities has been excluded from the computation of diluted net loss per share attributable to common stockholders calculation because their effect would have been antidilutive for the periods presented:
		March 31,
		2015	2014
		(unaudited)
	Convertible preferred stock	—	9,769,422
	Options to purchase common stock	2,308,886	1,454,283
	Warrants to purchase convertible preferred stock	—	1,975,532
	Total outstanding shares of common stock equivalents	2,308,886	13,199,237

Fair_Value_of_Financial_Instru1

Fair Value of Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2015
Fair Value Disclosures [Abstract]
Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis	The following table summarizes our financial assets and liabilities measured at fair value on a recurring basis (in thousands):
		31-Mar-15
		(unaudited)
	Assets:	LEVEL 1		LEVEL 2		LEVEL 3		TOTAL
	Money market funds	$	59,598	$	—	$	—	$	59,598
		31-Dec-14
	Assets:	LEVEL 1		LEVEL 2		LEVEL 3		TOTAL
	Money market funds	$	73,098	$	—	$	—	$	73,098

Inventory_Tables

Inventory (Tables)	3 Months Ended
	Mar. 31, 2015
Inventory Disclosure [Abstract]
Inventory	Inventory consists of the following (in thousands):
		March 31,		December 31,
		2015		2014
		(unaudited)
	Work in process	5		—
	Finished goods	22		25
	Total inventory	$	27	$	25

Accrued_Liabilities_Tables

Accrued Liabilities (Tables)	3 Months Ended
	Mar. 31, 2015
Payables and Accruals [Abstract]
Schedule of Accrued Liabilities	Accrued liabilities consist of the following (in thousands):
		March 31,		December 31,
		2015		2014
		(unaudited)
	Research and development services	$	1,438	$	1,845
	Legal and professional services	544		1,253
	Employee compensation	299		1,379
	Unearned revenue	225		524
	Total accrued liabilities	$	2,506	$	5,001

Stockholders_Equity_Tables

Stockholders' Equity (Tables)	3 Months Ended
	Mar. 31, 2015
Equity [Abstract]
Schedule of Shares of Common Stock Reserved for Future Issuance	Shares of common stock reserved for future issuance were as follows:
			March 31,			December 31,
			2015			2014
			(unaudited)
	Shares to be issued under the employee stock purchase plan		324,008			155,220
	Shares to be issued upon exercise of outstanding stock options		2,308,886			1,907,091
	Shares available for future stock option grants		1,471,553			1,274,067
	Shares of common stock reserved for future issuance		4,104,447			3,336,378
Summary of Stock Options	Summary stock option information is as follows:
			OPTIONS			WEIGHTED-			WEIGHTED-	AGGREGATE
			OUTSTANDING			AVERAGE			AVERAGE	INTRINSIC
						EXERCISE			REMAINING	VALUE
						PRICE			CONTRACT	(in thousands)
									TERM
									(in years)
	Outstanding at December 31, 2014		1,907,091			$	4.16		8.16	$	50,847
	Granted (unaudited)		528,660			$	30.49
	Exercised (unaudited)		(100,871	)		$	0.77
	Canceled (unaudited)		(25,994	)		$	24.94
	Outstanding at March 31, 2015 (unaudited)		2,308,886			$	10.07		8.45	$	30,802
	Vested and expected to vest after March 31, 2015 (unaudited)		2,139,528			$	9.58		8.38	$	29,289
	Exercisable as of March 31, 2015 (unaudited)		780,865			$	1.34		7	$	15,440
Schedule of Stock-Based Compensation Expense Recognized	Total stock-based compensation expense recognized in our statements of operations is as follows (in thousands):
			Three Months Ended March 31,
			2015				2014
			(unaudited)
	Employee:
	Research and development		$	402			$	51
	General and administrative		794				86
	Non-Employee:
	Research and development		35				50
	Total stock-based compensation expense		$	1,231			$	187
Schedule of Fair Value of Stock Options Granted to Employees	The fair values of stock options granted to employees were calculated using the following assumptions:
			Three Months Ended March 31,
			2015		2014
			(unaudited)
	Weighted-average estimated fair value		$22.58		*
	Risk-free interest rate (1)		1.50% - 1.64%		*
	Expected term of options (in years) (2)		5.50 - 6.08		*
	Expected stock price volatility (3)		82% - 91%		*
	Expected dividend yield (4)		—		*
	* No options were granted to employees during the three months ended March 31, 2014.
	-1	The risk-free interest rate assumption was based on zero-coupon U.S. Treasury instruments that had terms consistent with the expected term of our stock option grants.
	-2	We used the “simplified method” for options to determine the expected term of our stock option grants. Under this approach, the weighted-average expected life is presumed to be the average of the vesting term and the contractual term of the option.
	-3	Volatility is a measure of the amount by which a financial variable, such as share price, has fluctuated or is expected to fluctuate during a period. We analyzed the stock price volatility of companies at a similar stage of development to estimate expected volatility of our stock price.
	-4	We have never declared or paid cash dividends and do not presently plan to pay cash dividends in the foreseeable future.

Description_of_the_Business_Na

Description of the Business - Narrative (Details)	3 Months Ended
	Mar. 31, 2015
	platform
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of discovery platforms	2

Summary_of_Significant_Account2

Summary of Significant Accounting Policies - Segments (Details)	3 Months Ended
	Mar. 31, 2015
	segment
Accounting Policies [Abstract]
Number of operating segments	1

Summary_of_Significant_Account3

Summary of Significant Accounting Policies - Reverse Stock Split (Details)	0 Months Ended
	Jul. 14, 2014
Equity [Abstract]
Reverse stock split ratio	0.1223

Net_Loss_Per_Share_Common_Stoc

Net Loss Per Share - Common Stock Issuable Upon the Conversion or Exercise of Dilutive Securities Excluded from Diluted Net Loss Per Share Attributable to Common Stockholders (Details)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	2,308,886	13,199,237
Convertible Preferred Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	0	9,769,422
Equity Option [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	2,308,886	1,454,283
Warrant [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	0	1,975,532

Fair_Value_of_Financial_Instru2

Fair Value of Financial Instruments - Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) (Fair Value, Measurements, Recurring [Member], USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	$59,598	$73,098
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	59,598	73,098
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	0	0
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	$0	$0

Inventory_Details

Inventory (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Inventory Disclosure [Abstract]
Work in process	$5	$0
Finished goods	22	25
Total inventory	$27	$25

Accrued_Liabilities_Details

Accrued Liabilities (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Payables and Accruals [Abstract]
Research and development services	$1,438	$1,845
Legal and professional services	544	1,253
Employee compensation	299	1,379
Unearned revenue	225	524
Total accrued liabilities	$2,506	$5,001

Commitments_and_Contingencies_

Commitments and Contingencies - Narrative (Details) (USD $)	1 Months Ended
	Jan. 31, 2015	Mar. 31, 2015
Other Commitments [Line Items]
Optional lease extension period	5 years
Funds drawn on letter of credit		$0
Future minimum leave payments		2,400,000
Collaborative Arrangement [Member] | ZVex Product [Member]
Other Commitments [Line Items]
Potential future milestone payments		1,900,000
Infectious Disease Research Institute [Member] | Collaborative Arrangement [Member] | First GLA Product [Member]
Other Commitments [Line Items]
Potential future milestone payments		2,400,000
Infectious Disease Research Institute [Member] | Collaborative Arrangement [Member] | Subsequent GLA Products [Member]
Other Commitments [Line Items]
Potential future milestone payments		1,300,000
Financial Standby Letter of Credit [Member]
Other Commitments [Line Items]
Letter of credit provided as security deposit	121,000

Series_C_Convertible_Preferred1

Series C Convertible Preferred Stock Warrant Liability (Details) (USD $)	3 Months Ended		1 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Jul. 31, 2014	Oct. 31, 2013
Class of Warrant or Right [Line Items]
Change in fair value of convertible preferred stock warrant liability	$0	$2,711,000
Non-Operating Loss [Member]
Class of Warrant or Right [Line Items]
Change in fair value of convertible preferred stock warrant liability		2,700,000
Convertible Preferred Stock, Series C [Member]
Class of Warrant or Right [Line Items]
Number of warrants exercisable (in shares)				1,975,532
Warrant exercise price (in USD per share)				$8.18
Proceeds from warrants exercised			$8,100,000
Warrants exercised in period (in shares)			996,940
Common Stock [Member]
Class of Warrant or Right [Line Items]
Warrants exercised in period (in shares)			978,592
Additional shares of common stock issued (in shares)			311,923

License_and_Collaboration_Agre1

License and Collaboration Agreements - Narrative (Details) (USD $)	3 Months Ended		1 Months Ended	54 Months Ended	81 Months Ended	1 Months Ended	12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Aug. 31, 2014	Mar. 31, 2015	Mar. 31, 2015	Jul. 31, 2008	Dec. 31, 2009	Oct. 31, 2010
				license_agreement				license_agreement
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Research and development	$7,463,000	$4,078,000
GLAAS Discovery Platform [Member] | Collaborative Arrangement, Product [Member] | Sanofi [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Milestone revenue recognized			3,500,000
Milestone receivables			168,000,000
GLA [Member] | Collaborative Arrangement, Product [Member] | MedImmune LLC [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Milestone revenue recognized				5,500,000
Number of license agreements								3
Number of license agreements in full force and effect	2			2	2
GLA [Member] | Collaborative Arrangement, Product [Member] | MedImmune LLC [Member] | Minimum [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Milestone receivables	62,900,000			62,900,000	62,900,000
GLA [Member] | Collaborative Arrangement, Product [Member] | MedImmune LLC [Member] | Maximum [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Milestone receivables	75,000,000			75,000,000	75,000,000
GLA [Member] | Collaborative Arrangement [Member] | Infectious Disease Research Institute [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Research and development					1,900,000
GLA [Member] | Collaborative Arrangement [Member] | Infectious Disease Research Institute [Member] | Common Stock [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Value of common stock issued for license						59,000
First GLA Product [Member] | Collaborative Arrangement [Member] | Infectious Disease Research Institute [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Potential future milestone payments	2,400,000			2,400,000	2,400,000
Subsequent GLA Products [Member] | Collaborative Arrangement [Member] | Infectious Disease Research Institute [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Potential future milestone payments	1,300,000			1,300,000	1,300,000
Dendritic Cell-targeted Theraputic and Prophylactic Immunization Strategies [Member] | Collaborative Arrangement [Member] | California Institute of Technology [Member] | Common Stock [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Value of common stock issued for license							25,000
Potential future milestone payments	1,600,000			1,600,000	1,600,000
Herpes Simplex Virus Immune Therapy [Member] | Collaborative Arrangement, Product [Member] | Sanofi [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Outstanding receivable	1,500,000			1,500,000	1,500,000
Unearned revenue	193,000			193,000	193,000
Herpes Simplex Virus Immune Therapy [Member] | Collaborative Arrangement, Product [Member] | Sanofi [Member] | Collaboration Revenue [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Milestone revenue recognized	$1,800,000

Stockholders_Equity_Schedule_o

Stockholders' Equity - Schedule of Shares of Common Stock Reserved for Future Issuance (Details)	Mar. 31, 2015	Dec. 31, 2014
Class of Stock [Line Items]
Common stock reserved for future issuance (in shares)	4,104,447	3,336,378
Employee Stock [Member]
Class of Stock [Line Items]
Common stock reserved for future issuance (in shares)	324,008	155,220
Stock Options Outstanding [Member]
Class of Stock [Line Items]
Common stock reserved for future issuance (in shares)	2,308,886	1,907,091
Future Stock Grants [Member]
Class of Stock [Line Items]
Common stock reserved for future issuance (in shares)	1,471,553	1,274,067

Stockholders_Equity_Summary_of

Stockholders' Equity - Summary of Stock Options (Details) (USD $)	3 Months Ended	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Options outstanding, Beginning balance (in shares)	1,907,091
Options granted in period (in shares)	528,660
Options exercised in period (in shares)	-100,871
Options cancelled in period (in shares)	-25,994
Options outstanding, Ending balance (in shares)	2,308,886	1,907,091
Options vested and expected to vest after March 31, 2015 (in shares)	2,139,528
Exercisable options as of March 31, 2015 (in shares)	780,865
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Weighted average exercise price, Beginning balance (in USD per share)	$4.16
Weighted average exercise price of options granted in period (in USD per share)	$30.49
Weighted average exercise price of options exercised in period (in USD per share)	$0.77
Weighted average exercise price of options cancelled in period (in USD per share)	$24.94
Weighted average exercise price, Ending balance (in USD per share)	$10.07	$4.16
Weighted average exercise price of options vested and expected to vest after March 31, 2015 (in USD per share)	$9.58
Weighted average exercise price of exercisable options as of March 31, 2015 (in USD per share)	$1.34
Weighted average remaining contract term for outstanding options, Beginning	8 years 5 months 12 days	8 years 1 month 27 days
Weighted average remaining contract term for options vested and expected to vest after March 31, 2015	8 years 4 months 17 days
Weighted average remaining contract term for exercisable options as of March 31, 2015	7 years
Aggregate intrinsic value, beginning balance	$50,847
Aggregate intrinsic value, ending balance	30,802	50,847
Aggregate intrinsic value of options vested and expected to vest after March 31, 2015	29,289
Aggregate intrinsic value of exercisable options as of March 31, 2015	$15,440

Stockholders_Equity_Schedule_o1

Stockholders' Equity - Schedule of Stock-Based Compensation Expense Recognized (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Employee share-based compensation expense	$1,231	$187
Employee [Member] | Research and Development Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Employee share-based compensation expense	402	51
Employee [Member] | General and Administrative Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Employee share-based compensation expense	794	86
Non-Employee [Member] | Research and Development Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Employee share-based compensation expense	$35	$50

Stockholders_Equity_Schedule_o2

Stockholders' Equity - Schedule of Fair Value of Stock Options Granted to Employees (Details) (Employee Stock Option [Member], USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average estimated fair value	$22.58
Risk-free interest rate min	1.50%
Risk-free interest rate max	1.64%
Expected dividend yield	0.00%
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Time to maturity	5 years 6 months
Expected stock price volatility min	82.00%
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Time to maturity	6 years 0 months 29 days
Expected stock price volatility min	91.00%

Stockholders_Equity_Narrative_

Stockholders' Equity - Narrative (Details) (USD $)	3 Months Ended		0 Months Ended	1 Months Ended
In Millions, except Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014	Jan. 01, 2015	Jul. 31, 2014	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares outstanding (in shares)	16,979,688				16,878,817
Common stock reserved for future issuance (in shares)	4,104,447				3,336,378
Intrinsic value of stock options exercised	$2.60	$0
2014 Omnibus Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual increase in common stock available for issuance (as a percent)				4.00%
Increase in authorized shares			675,152
Common stock authorized (in shares)				1,400,000
2008 and 2014 Equity Incentive Plans [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock authorized (in shares)	1,471,553
Employee Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance (in shares)	324,008				155,220
Employee Stock [Member] | 2014 Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance (in shares)				155,220
Annual increase in common stock available for issuance (as a percent)				1.00%
Annual increase in common stock available for issuance (in shares)				200,000
Increase in authorized shares			168,788
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance (in shares)	2,308,886				1,907,091
Unrecognized stock based compensation expense	$13.90
Weighted average recognition period for stock-based compensation expense	3 years 3 months 14 days
Employee Stock Option [Member] | 2008 and 2014 Equity Incentive Plans [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting term	4 years
Option expiration period	10 years

Legal_Proceedings_Details

Legal Proceedings (Details) (TheraVectys SA v. Immune Design Corp. [Member], USD $)	0 Months Ended	1 Months Ended
In Thousands, unless otherwise specified	Jul. 24, 2014	Oct. 31, 2013
	count
Pending Litigation [Member]
Loss Contingencies [Line Items]
Number of counts for relief	4
Minimum [Member] | Voluntarily Dismissed Litigation [Member]
Loss Contingencies [Line Items]
Claimed damages		$75

Subsequent_Events_Narrative_De

Subsequent Events - Narrative (Details) (Subsequent Event [Member], USD $)	1 Months Ended
In Millions, except Share data, unless otherwise specified	Apr. 30, 2015
Subsequent Event [Line Items]
Net proceeds from stock issuance	$74.20
Common Stock [Member]
Subsequent Event [Line Items]
Additional shares of common stock issued (in shares)	3,000,000