Document and Entity Information
Document and Entity Information - shares | 6 Months Ended | |
Jun. 30, 2017 | Jul. 31, 2017 | |
Document And Entity Information [Abstract] | ||
Document Type | 10-Q | |
Amendment Flag | false | |
Document Period End Date | Jun. 30, 2017 | |
Document Fiscal Year Focus | 2,017 | |
Document Fiscal Period Focus | Q2 | |
Trading Symbol | OXGN | |
Entity Registrant Name | MATEON THERAPEUTICS INC | |
Entity Central Index Key | 908,259 | |
Current Fiscal Year End Date | --12-31 | |
Entity Filer Category | Smaller Reporting Company | |
Entity Common Stock, Shares Outstanding | 26,544,934 |
Condensed Balance Sheets
Condensed Balance Sheets - USD ($) $ in Thousands | Jun. 30, 2017 | Dec. 31, 2016 |
Current assets: | ||
Cash and cash equivalents | $ 5,004 | $ 3,535 |
Short-term investments | 8,512 | |
Prepaid clinical trial expenses | 1,162 | 1,946 |
Other prepaid expenses and current assets | 324 | 77 |
Total current assets | 6,490 | 14,070 |
Property and equipment, net | 6 | 11 |
Other assets | 33 | 33 |
Total assets | 6,529 | 14,114 |
Current liabilities: | ||
Accounts payable | 401 | 310 |
Accrued compensation and employee benefits | 483 | 842 |
Accrued clinical trial expenses | 120 | 64 |
Other accrued liabilities | 421 | 398 |
Total current liabilities | 1,425 | 1,614 |
Commitments and contingencies | ||
Stockholders' equity: | ||
Preferred stock, $0.01 par value, 15,000 shares authorized; No shares issued and outstanding | ||
Common stock, $0.01 par value, 70,000 shares authorized; 26,545 shares issued and outstanding | 265 | 265 |
Additional paid-in capital | 291,144 | 290,698 |
Accumulated deficit | (286,305) | (278,463) |
Total stockholders' equity | 5,104 | 12,500 |
Total liabilities and stockholders' equity | $ 6,529 | $ 14,114 |
Condensed Balance Sheets (Paren
Condensed Balance Sheets (Parenthetical) - $ / shares | Jun. 30, 2017 | Dec. 31, 2016 |
Statement of Financial Position [Abstract] | ||
Preferred stock, par value | $ 0.01 | $ 0.01 |
Preferred stock, shares authorized | 15,000,000 | 15,000,000 |
Preferred stock, shares issued | 0 | 0 |
Preferred stock, shares outstanding | 0 | 0 |
Common stock, par value | $ 0.01 | $ 0.01 |
Common stock, shares authorized | 70,000,000 | 70,000,000 |
Common stock, shares issued | 26,545,000 | 26,545,000 |
Common stock, shares outstanding | 26,545,000 | 26,545,000 |
Condensed Statements of Compreh
Condensed Statements of Comprehensive Loss (Unaudited) - USD ($) shares in Thousands, $ in Thousands | 3 Months Ended | 6 Months Ended | ||
Jun. 30, 2017 | Jun. 30, 2016 | Jun. 30, 2017 | Jun. 30, 2016 | |
Operating expenses: | ||||
Research and development | $ 3,019 | $ 2,374 | $ 5,867 | $ 4,354 |
General and administrative | 877 | 1,296 | 1,999 | 2,668 |
Total operating expenses | 3,896 | 3,670 | 7,866 | 7,022 |
Loss from operations | (3,896) | (3,670) | (7,866) | (7,022) |
Interest income | 12 | 29 | 26 | 57 |
Other expense | (2) | (1) | ||
Net loss and comprehensive loss | $ (3,884) | $ (3,641) | $ (7,842) | $ (6,966) |
Basic and diluted net loss per share attributable to common stock | $ (0.15) | $ (0.14) | $ (0.30) | $ (0.26) |
Weighted-average number of common shares outstanding | 26,545 | 26,545 | 26,545 | 26,545 |
Condensed Statements of Cash Fl
Condensed Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands | 6 Months Ended | |
Jun. 30, 2017 | Jun. 30, 2016 | |
Operating activities: | ||
Net loss | $ (7,842) | $ (6,966) |
Adjustments to reconcile net loss to net cash used in operating activities: | ||
Depreciation | 5 | 11 |
Stock-based compensation | 446 | 427 |
Changes in operating assets and liabilities: | ||
Prepaid expenses and other current assets | 537 | (930) |
Accounts payable and accrued expenses | (189) | (486) |
Net cash used in operating activities | (7,043) | (7,944) |
Investing activities: | ||
Purchase of short-term investments | (15,604) | |
Sale of short-term investments | 8,512 | 4,202 |
Net cash provided by (used in) investing activities | 8,512 | (11,402) |
Increase (decrease) in cash and cash equivalents | 1,469 | (19,346) |
Cash and cash equivalents at beginning of period | 3,535 | 27,285 |
Cash and cash equivalents at end of period | $ 5,004 | $ 7,939 |
Summary of Significant Accounti
Summary of Significant Accounting Policies | 6 Months Ended |
Jun. 30, 2017 | |
Accounting Policies [Abstract] | |
Summary of Significant Accounting Policies | 1. Summary of Significant Accounting Policies Description of Business Mateon Therapeutics, Inc. (“Mateon” or the “Company”) is a clinical-stage biopharmaceutical company seeking to realize the full potential of vascular targeted therapy in oncology. Vascular targeted therapy includes vascular disrupting agents (VDAs), such as the investigational drugs that Mateon is developing, and anti-angiogenic agents (AAs), a number of which are approved and widely used in oncology indications. Mateon’s VDAs selectively obstruct a tumor’s blood supply without obstructing the blood supply to normal tissues, and treatment with Mateon’s VDAs has been shown to lead to significant central tumor necrosis. The Company believes that the treatment of cancer would be significantly improved if VDAs and AAs were used together, due to their complementary mechanisms of action. In combination, the VDA would occlude the blood vessels in the interior of a tumor while the AA would prevent the formation of new tumor blood vessels. The Company has two VDA drug candidates currently being tested in clinical trials, CA4P (combretastatin A4 phosphate, or fosbretabulin) and OXi4503. The Company was originally incorporated under the name OXiGENE, Inc. in 1988 in the state of New York, reincorporated in 1992 in the state of Delaware and changed its name to Mateon Therapeutics, Inc. on June 17, 2016. Basis of Presentation The accompanying unaudited condensed financial statements have been prepared in accordance with U.S. generally accepted accounting principles for interim financial information and with the instructions to Form 10-Q Regulation S-X. The balance sheet at December 31, 2016 has been derived from the audited financial statements at that date but does not include all of the information and footnotes required by U.S. generally accepted accounting principles for complete financial statements. For further information, refer to the financial statements and footnotes thereto included in the Annual Report on Form 10-K Use of Estimates The preparation of financial statements in conformity with U.S. generally accepted accounting principles requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of income and expenses during the reporting period. Actual results could differ from those estimates. Cash Equivalents Highly liquid investments with original maturities of three months or less at the date of purchase are considered to be cash equivalents. Cash equivalents are stated at fair value. Short-term Investments All marketable securities have been classified as “available for sale” and are carried at fair value, based upon quoted market prices. The Company considers its available-for-sale available-for-sale Going Concern Evaluation The principal source of the Company’s working capital to date has been the proceeds from the sale of equity. The Company has experienced net losses every year since inception and, as of June 30, 2017, had cash and cash equivalents of $5.0 million and an accumulated deficit of over $286 million. The Company’s net loss was $3.9 million and $7.8 million for the three and six month periods ended June 30, 2017, respectively. The Company has no source of revenue and does not expect to receive any product revenue in the near future. If the Company remains in operation, the Company expects to incur significant additional operating losses over at least the next several years, principally as a result of the Company’s continuing clinical trials for its investigational drugs. Based on the Company’s planned operations, Management expects the Company’s existing cash and cash equivalents to support its operations only into October 2017. Prior to this time, the Company will need to secure additional funding or it could be forced to curtail or terminate its drug development programs and its operations. Because the Company does not currently have a source of working capital that will sustain its planned operations past October 2017, Management has determined that there is substantial doubt about the Company’s ability to continue as a going concern. Any additional equity financing, if available, may not be available on favorable terms and would most likely be dilutive to current stockholders. Any debt financing, if available, would likely involve restrictive covenants and may also result in dilution to current stockholders. If the Company accesses funds through collaborative or licensing arrangements, it may be required to relinquish rights to some of its technologies or product candidates that it would otherwise seek to develop or commercialize on its own, on terms that are not favorable to the Company. The Company’s ability to access capital in any form is not assured and is likely to be dependent on upcoming clinical trial results, which are not under the control of the Company. If access to additional capital is not achieved on a timely basis, it would materially harm the Company’s business, financial condition and results of operations. Recent Accounting Pronouncements In February 2016, the Financial Accounting Standards Board, or FASB, issued ASU No. 2016-2, right-of-use In March 2016, the FASB issued ASU No. 2016-09, tax-withholding In August 2016, the FASB issued ASU No. 2016-15, |
Cash, Cash Equivalents and Shor
Cash, Cash Equivalents and Short-Term Investments | 6 Months Ended |
Jun. 30, 2017 | |
Cash and Cash Equivalents [Abstract] | |
Cash, Cash Equivalents and Short-Term Investments | 2. Cash, Cash Equivalents and Short-Term Investments Cash, cash equivalents and short-term investments consisted of the following (in thousands): June 30, 2017 Amortized Unrealized Unrealized Estimated Fair Cash $ 304 $ — $ — $ 304 Money market funds 4,700 — — 4,700 Total cash and cash equivalents $ 5,004 $ — $ — $ 5,004 December 31, 2016 Amortized Unrealized Unrealized Estimated Fair Cash $ 671 $ — $ — $ 671 Money market funds 2,864 — — 2,864 U.S. government treasury bills 3,008 — — 3,008 Corporate bonds and commercial paper 5,504 — — 5,504 $ 12,047 $ — $ — $ 12,047 Reported as: Cash and cash equivalents $ 3,535 Short-term investments 8,512 Total cash, cash equivalents and short-term investments $ 12,047 |
Fair Value Measurements
Fair Value Measurements | 6 Months Ended |
Jun. 30, 2017 | |
Fair Value Disclosures [Abstract] | |
Fair Value Measurements | 3. Fair Value Measurements Fair value is defined as the price at which an asset could be exchanged or a liability transferred in a transaction between knowledgeable, willing parties in the principal or most advantageous market for the asset or liability. Where available, fair value is based on observable market prices or parameters or derived from such prices or parameters. Where observable prices or parameters are not available, valuation models are applied. Assets and liabilities recorded at fair value are categorized based upon the level of judgment associated with the inputs used to measure their fair value. Hierarchical levels directly related to the amount of subjectivity associated with the inputs to fair valuation of these assets and liabilities, are as follows: Level 1—Inputs are unadjusted, quoted prices in active markets for identical assets at the reporting date. Active markets are those in which transactions for the asset or liability occur in sufficient frequency and volume to provide reasonably accurate pricing information on an ongoing basis. Level 2—Inputs, other than quoted prices included in Level 1, that are either directly or indirectly observable for the asset or liability through correlation with market data at the reporting date and for the duration of the instrument’s anticipated life. The Company utilizes third party pricing services in developing fair value measurements where fair value is based on observable market inputs, including benchmark yields, reported trades, broker/dealer quotes, bids, offers and other reference data. The Company uses quotes from external pricing service providers and other on-line 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 reflect management’s best estimate of what market participants would use in pricing the asset or liability at the reporting date. Consideration is given to the risk inherent in the valuation technique and the risk inherent in the inputs to the model. Financial assets measured at fair value on a recurring basis are categorized in the tables below based upon the lowest level of significant input to the valuations (in thousands): June 30, 2017 Level 1 Level 2 Level 3 Total Money market funds 4,700 — — 4,700 Total $ 4,700 $ — $ — $ 4,700 December 31, 2016 Level 1 Level 2 Level 3 Total Money market funds $ 2,864 $ — $ — $ 2,864 U.S. government treasury bills — 3,008 — 3,008 Corporate bonds and commercial paper — 5,504 — 5,504 Total $ 2,864 $ 8,512 $ — $ 11,376 |
Stockholders' Equity
Stockholders' Equity | 6 Months Ended |
Jun. 30, 2017 | |
Equity [Abstract] | |
Stockholders' Equity | 4. Stockholders’ Equity The following is a summary of the Company’s outstanding common stock warrants: Expiration Date Exercise June 30, 2017 December 31, 2016 (in thousands) 6/14/2017 $ 3.70 — 216 4/16/2018 $ 3.40 1,460 1,460 9/23/2018 $ 2.80 147 147 2/11/2019 $ 2.56 293 293 2/18/2019 $ 2.75 1,872 1,872 8/28/2019 $ 2.90 2,700 2,700 3/20/2020 $ 2.13 234 234 3/25/2020 $ 1.71 2,920 2,920 9,626 9,842 The following is a summary of the Company’s stock option activity under its equity incentive plans: Options Options Weighted Weighted Aggregate (in thousands) (years) (in thousands) Balance at December 31, 2016 549 4,177 $ 1.47 8.14 Options authorized 2,000 Options granted (2,484 ) 2,484 $ 0.42 Options forfeited 720 (720 ) $ 1.66 Balance at June 30, 2017 785 5,941 $ 1.01 8.30 $ — Vested and exercisable at June 30, 2017 1,722 $ 1.29 7.73 $ — Vested and expected to vest at June 30, 2017 4,540 $ 0.90 8.17 $ — Unvested at June 30, 2017 4,219 $ 0.89 As of June 30, 2017, there was approximately $1.3 million of unrecognized compensation cost related to stock option awards that is expected to be recognized as expense over a weighted average period of approximately 2.4 years. The fair values for the stock options granted were estimated at the date of grant using the Black-Scholes option pricing model with the following weighted-average assumptions for the periods indicated: Six months ended June 30, 2017 2016 Risk-free interest rate 2.0 % 1.5 % Expected life (years) 6.0 6.0 Expected volatility 88 % 89 % Dividend yield 0 % 0 % |
Net Loss Per Share
Net Loss Per Share | 6 Months Ended |
Jun. 30, 2017 | |
Earnings Per Share [Abstract] | |
Net Loss Per Share | 5. Net Loss Per Share Basic and diluted net loss per share was calculated by dividing the net loss per share attributed to the Company’s common shares by the weighted-average number of common shares outstanding during the period. Diluted net loss per share includes the effect of all dilutive, potentially issuable common equivalent shares as defined using the treasury stock method. All of the Company’s common stock equivalents are anti-dilutive due to the Company’s net loss position for all periods presented. Accordingly, common stock equivalents of approximately 5,941,000 stock options and 9,626,000 warrants at June 30, 2017 and 4,139,000 stock options and 9,842,000 warrants at June 30, 2016, were excluded from the calculation of weighted average shares for diluted net loss per share. |
Summary of Significant Accoun11
Summary of Significant Accounting Policies (Policies) | 6 Months Ended |
Jun. 30, 2017 | |
Accounting Policies [Abstract] | |
Description of Business | Description of Business Mateon Therapeutics, Inc. (“Mateon” or the “Company”) is a clinical-stage biopharmaceutical company seeking to realize the full potential of vascular targeted therapy in oncology. Vascular targeted therapy includes vascular disrupting agents (VDAs), such as the investigational drugs that Mateon is developing, and anti-angiogenic agents (AAs), a number of which are approved and widely used in oncology indications. Mateon’s VDAs selectively obstruct a tumor’s blood supply without obstructing the blood supply to normal tissues, and treatment with Mateon’s VDAs has been shown to lead to significant central tumor necrosis. The Company believes that the treatment of cancer would be significantly improved if VDAs and AAs were used together, due to their complementary mechanisms of action. In combination, the VDA would occlude the blood vessels in the interior of a tumor while the AA would prevent the formation of new tumor blood vessels. The Company has two VDA drug candidates currently being tested in clinical trials, CA4P (combretastatin A4 phosphate, or fosbretabulin) and OXi4503. The Company was originally incorporated under the name OXiGENE, Inc. in 1988 in the state of New York, reincorporated in 1992 in the state of Delaware and changed its name to Mateon Therapeutics, Inc. on June 17, 2016. |
Basis of Presentation | Basis of Presentation The accompanying unaudited condensed financial statements have been prepared in accordance with U.S. generally accepted accounting principles for interim financial information and with the instructions to Form 10-Q Regulation S-X. The balance sheet at December 31, 2016 has been derived from the audited financial statements at that date but does not include all of the information and footnotes required by U.S. generally accepted accounting principles for complete financial statements. For further information, refer to the financial statements and footnotes thereto included in the Annual Report on Form 10-K |
Use of Estimates | Use of Estimates The preparation of financial statements in conformity with U.S. generally accepted accounting principles requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of income and expenses during the reporting period. Actual results could differ from those estimates. |
Cash Equivalents | Cash Equivalents Highly liquid investments with original maturities of three months or less at the date of purchase are considered to be cash equivalents. Cash equivalents are stated at fair value. |
Short-term Investments | Short-term Investments All marketable securities have been classified as “available for sale” and are carried at fair value, based upon quoted market prices. The Company considers its available-for-sale available-for-sale |
Going Concern Evaluation | Going Concern Evaluation The principal source of the Company’s working capital to date has been the proceeds from the sale of equity. The Company has experienced net losses every year since inception and, as of June 30, 2017, had cash and cash equivalents of $5.0 million and an accumulated deficit of over $286 million. The Company’s net loss was $3.9 million and $7.8 million for the three and six month periods ended June 30, 2017, respectively. The Company has no source of revenue and does not expect to receive any product revenue in the near future. If the Company remains in operation, the Company expects to incur significant additional operating losses over at least the next several years, principally as a result of the Company’s continuing clinical trials for its investigational drugs. Based on the Company’s planned operations, Management expects the Company’s existing cash and cash equivalents to support its operations only into October 2017. Prior to this time, the Company will need to secure additional funding or it could be forced to curtail or terminate its drug development programs and its operations. Because the Company does not currently have a source of working capital that will sustain its planned operations past October 2017, Management has determined that there is substantial doubt about the Company’s ability to continue as a going concern. Any additional equity financing, if available, may not be available on favorable terms and would most likely be dilutive to current stockholders. Any debt financing, if available, would likely involve restrictive covenants and may also result in dilution to current stockholders. If the Company accesses funds through collaborative or licensing arrangements, it may be required to relinquish rights to some of its technologies or product candidates that it would otherwise seek to develop or commercialize on its own, on terms that are not favorable to the Company. The Company’s ability to access capital in any form is not assured and is likely to be dependent on upcoming clinical trial results, which are not under the control of the Company. If access to additional capital is not achieved on a timely basis, it would materially harm the Company’s business, financial condition and results of operations. |
Recent Accounting Pronouncements | Recent Accounting Pronouncements In February 2016, the Financial Accounting Standards Board, or FASB, issued ASU No. 2016-2, right-of-use In March 2016, the FASB issued ASU No. 2016-09, tax-withholding In August 2016, the FASB issued ASU No. 2016-15, |
Cash, Cash Equivalents and Sh12
Cash, Cash Equivalents and Short-Term Investments (Tables) | 6 Months Ended |
Jun. 30, 2017 | |
Cash and Cash Equivalents [Abstract] | |
Summary Of Cash, Cash Equivalents and Short-Term Investments | Cash, cash equivalents and short-term investments consisted of the following (in thousands): June 30, 2017 Amortized Unrealized Unrealized Estimated Fair Cash $ 304 $ — $ — $ 304 Money market funds 4,700 — — 4,700 Total cash and cash equivalents $ 5,004 $ — $ — $ 5,004 December 31, 2016 Amortized Unrealized Unrealized Estimated Fair Cash $ 671 $ — $ — $ 671 Money market funds 2,864 — — 2,864 U.S. government treasury bills 3,008 — — 3,008 Corporate bonds and commercial paper 5,504 — — 5,504 $ 12,047 $ — $ — $ 12,047 Reported as: Cash and cash equivalents $ 3,535 Short-term investments 8,512 Total cash, cash equivalents and short-term investments $ 12,047 |
Fair Value Measurements (Tables
Fair Value Measurements (Tables) | 6 Months Ended |
Jun. 30, 2017 | |
Fair Value Disclosures [Abstract] | |
Summary of Financial Assets Measured at Fair Value on a Recurring Basis | Financial assets measured at fair value on a recurring basis are categorized in the tables below based upon the lowest level of significant input to the valuations (in thousands): June 30, 2017 Level 1 Level 2 Level 3 Total Money market funds 4,700 — — 4,700 Total $ 4,700 $ — $ — $ 4,700 December 31, 2016 Level 1 Level 2 Level 3 Total Money market funds $ 2,864 $ — $ — $ 2,864 U.S. government treasury bills — 3,008 — 3,008 Corporate bonds and commercial paper — 5,504 — 5,504 Total $ 2,864 $ 8,512 $ — $ 11,376 |
Stockholders' Equity (Tables)
Stockholders' Equity (Tables) | 6 Months Ended |
Jun. 30, 2017 | |
Equity [Abstract] | |
Summary of the Company's Outstanding Common Stock Warrants | The following is a summary of the Company’s outstanding common stock warrants: Expiration Date Exercise June 30, 2017 December 31, 2016 (in thousands) 6/14/2017 $ 3.70 — 216 4/16/2018 $ 3.40 1,460 1,460 9/23/2018 $ 2.80 147 147 2/11/2019 $ 2.56 293 293 2/18/2019 $ 2.75 1,872 1,872 8/28/2019 $ 2.90 2,700 2,700 3/20/2020 $ 2.13 234 234 3/25/2020 $ 1.71 2,920 2,920 9,626 9,842 |
Summary of the Company's Stock Option Activity under Equity Incentive Plans | The following is a summary of the Company’s stock option activity under its equity incentive plans: Options Options Weighted Weighted Aggregate (in thousands) (years) (in thousands) Balance at December 31, 2016 549 4,177 $ 1.47 8.14 Options authorized 2,000 Options granted (2,484 ) 2,484 $ 0.42 Options forfeited 720 (720 ) $ 1.66 Balance at June 30, 2017 785 5,941 $ 1.01 8.30 $ — Vested and exercisable at June 30, 2017 1,722 $ 1.29 7.73 $ — Vested and expected to vest at June 30, 2017 4,540 $ 0.90 8.17 $ — Unvested at June 30, 2017 4,219 $ 0.89 |
Weighted-Average Assumptions | The fair values for the stock options granted were estimated at the date of grant using the Black-Scholes option pricing model with the following weighted-average assumptions for the periods indicated: Six months ended June 30, 2017 2016 Risk-free interest rate 2.0 % 1.5 % Expected life (years) 6.0 6.0 Expected volatility 88 % 89 % Dividend yield 0 % 0 % |
Summary of Significant Accoun15
Summary of Significant Accounting Policies - Additional Information (Detail) $ in Thousands | 3 Months Ended | 6 Months Ended | ||||
Jun. 30, 2017USD ($) | Jun. 30, 2016USD ($) | Jun. 30, 2017USD ($)Candidate | Jun. 30, 2016USD ($) | Dec. 31, 2016USD ($) | Dec. 31, 2015USD ($) | |
Organization, Consolidation and Presentation of Financial Statements [Abstract] | ||||||
Number of VDA drug candidates tested | Candidate | 2 | |||||
Accumulated deficit | $ (286,305) | $ (286,305) | $ (278,463) | |||
Cash and cash equivalents | 5,004 | $ 7,939 | 5,004 | $ 7,939 | $ 3,535 | $ 27,285 |
Net loss | $ (3,884) | $ (3,641) | $ (7,842) | $ (6,966) | ||
Substantial doubt about going concern, management's evaluation | The Company’s existing cash and cash equivalents to support its operations only into October 2017. Prior to this time, the Company will need to secure additional funding or it could be forced to curtail or terminate its drug development programs and its operations. Because the Company does not currently have a source of working capital that will sustain its planned operations past October 2017, Management has determined that there is substantial doubt about the Company’s ability to continue as a going concern. | |||||
Substantial doubt about going concern | Any additional equity financing, if available, may not be available on favorable terms and would most likely be dilutive to current stockholders. |
Cash, Cash Equivalents and Sh16
Cash, Cash Equivalents and Short-Term Investments - Summary of Cash, Cash Equivalents and Short-Term Investments (Detail) - USD ($) $ in Thousands | Jun. 30, 2017 | Dec. 31, 2016 |
Schedule of Available-for-sale Securities [Line Items] | ||
Amortized Cost | $ 5,004 | $ 12,047 |
Unrealized Gain | 0 | 0 |
Unrealized (Loss) | 0 | 0 |
Estimated Fair Value | 5,004 | 12,047 |
Cash and Cash Equivalents [Member] | ||
Schedule of Available-for-sale Securities [Line Items] | ||
Estimated Fair Value | 3,535 | |
Short-term Investments [Member] | ||
Schedule of Available-for-sale Securities [Line Items] | ||
Estimated Fair Value | 8,512 | |
Cash [Member] | ||
Schedule of Available-for-sale Securities [Line Items] | ||
Amortized Cost | 304 | 671 |
Unrealized Gain | 0 | 0 |
Unrealized (Loss) | 0 | 0 |
Estimated Fair Value | 304 | 671 |
Money Market Funds [Member] | ||
Schedule of Available-for-sale Securities [Line Items] | ||
Amortized Cost | 4,700 | 2,864 |
Unrealized Gain | 0 | 0 |
Unrealized (Loss) | 0 | 0 |
Estimated Fair Value | $ 4,700 | 2,864 |
U.S. Government Treasury Bills [Member] | ||
Schedule of Available-for-sale Securities [Line Items] | ||
Amortized Cost | 3,008 | |
Unrealized Gain | 0 | |
Unrealized (Loss) | 0 | |
Estimated Fair Value | 3,008 | |
Corporate Bonds and Commercial Paper [Member] | ||
Schedule of Available-for-sale Securities [Line Items] | ||
Amortized Cost | 5,504 | |
Unrealized Gain | 0 | |
Unrealized (Loss) | 0 | |
Estimated Fair Value | $ 5,504 |
Fair Value Measurements - Summa
Fair Value Measurements - Summary of Financial Assets Measured at Fair Value on a Recurring Basis (Detail) - Fair Value Measurements Recurring [Member] - USD ($) $ in Thousands | Jun. 30, 2017 | Dec. 31, 2016 |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Assets fair value disclosure | $ 4,700 | $ 11,376 |
Money Market Funds [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Assets fair value disclosure | 4,700 | 2,864 |
U.S. Government Treasury Bills [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Assets fair value disclosure | 3,008 | |
Corporate Bonds and Commercial Paper [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Assets fair value disclosure | 5,504 | |
Level 1 [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Assets fair value disclosure | 4,700 | 2,864 |
Level 1 [Member] | Money Market Funds [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Assets fair value disclosure | $ 4,700 | 2,864 |
Level 2 [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Assets fair value disclosure | 8,512 | |
Level 2 [Member] | U.S. Government Treasury Bills [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Assets fair value disclosure | 3,008 | |
Level 2 [Member] | Corporate Bonds and Commercial Paper [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Assets fair value disclosure | $ 5,504 |
Stockholders' Equity - Summary
Stockholders' Equity - Summary of Company's Outstanding Common Stock Warrants (Detail) - $ / shares shares in Thousands | 6 Months Ended | |
Jun. 30, 2017 | Dec. 31, 2016 | |
Class of Warrant or Right [Line Items] | ||
Number of warrants outstanding | 9,626 | 9,842 |
2014 Private Placement [Member] | ||
Class of Warrant or Right [Line Items] | ||
Expiration Date | Jun. 14, 2017 | |
Exercise Price | $ 3.70 | |
Number of warrants outstanding | 216 | |
Private Placement Series A [Member] | ||
Class of Warrant or Right [Line Items] | ||
Expiration Date | Apr. 16, 2018 | |
Exercise Price | $ 3.40 | |
Number of warrants outstanding | 1,460 | 1,460 |
2013 Private Placement [Member] | ||
Class of Warrant or Right [Line Items] | ||
Expiration Date | Sep. 23, 2018 | |
Exercise Price | $ 2.80 | |
Number of warrants outstanding | 147 | 147 |
2014 Public Offering [Member] | ||
Class of Warrant or Right [Line Items] | ||
Expiration Date | Feb. 11, 2019 | |
Exercise Price | $ 2.56 | |
Number of warrants outstanding | 293 | 293 |
2014 Public Offering [Member] | ||
Class of Warrant or Right [Line Items] | ||
Expiration Date | Feb. 18, 2019 | |
Exercise Price | $ 2.75 | |
Number of warrants outstanding | 1,872 | 1,872 |
2014 Private Placement [Member] | ||
Class of Warrant or Right [Line Items] | ||
Expiration Date | Aug. 28, 2019 | |
Exercise Price | $ 2.90 | |
Number of warrants outstanding | 2,700 | 2,700 |
2015 Private Placement [Member] | ||
Class of Warrant or Right [Line Items] | ||
Expiration Date | Mar. 20, 2020 | |
Exercise Price | $ 2.13 | |
Number of warrants outstanding | 234 | 234 |
2015 Private Placement [Member] | ||
Class of Warrant or Right [Line Items] | ||
Expiration Date | Mar. 25, 2020 | |
Exercise Price | $ 1.71 | |
Number of warrants outstanding | 2,920 | 2,920 |
Stockholders' Equity - Summar19
Stockholders' Equity - Summary of the Company's Stock Option Activity under Equity Incentive Plans (Detail) $ / shares in Units, $ in Thousands | 6 Months Ended |
Jun. 30, 2017USD ($)$ / sharesshares | |
Disclosure of Compensation Related Costs, Share-based Payments [Abstract] | |
Options Available for Grant, Beginning Balance | 549,000 |
Options Available for Grant, Options authorized | 2,000,000 |
Options Available for Grant, Options granted | (2,484,000) |
Options Available for Grant, Options forfeited | 720,000 |
Options Available for Grant, Ending Balance | 785,000 |
Options Outstanding, Beginning Balance | 4,177,000 |
Options Outstanding, Options granted | 2,484,000 |
Options Outstanding, Options forfeited | (720,000) |
Options Outstanding, Ending Balance | 5,941,000 |
Options Outstanding, Vested and exercisable | 1,722,000 |
Options Outstanding, Vested and expected to vest, Ending Balance | 4,540,000 |
Options Outstanding, Unvested | 4,219,000 |
Weighted Average Exercise Price, Beginning Balance | $ / shares | $ 1.47 |
Weighted Average Exercise Price, Options granted | $ / shares | 0.42 |
Weighted Average Exercise Price, Options forfeited | $ / shares | 1.66 |
Weighted Average Exercise Price, Ending Balance | $ / shares | 1.01 |
Weighted Average Exercise Price, Vested and exercisable | $ / shares | 1.29 |
Weighted Average Exercise Price, Vested and expected to vest, Ending Balance | $ / shares | 0.90 |
Weighted Average Exercise Price, Unvested | $ / shares | $ 0.89 |
Weighted Average Remaining Contractual Life, Beginning Balance | 8 years 1 month 20 days |
Weighted Average Remaining Contractual Life, Ending Balance | 8 years 3 months 19 days |
Weighted Average Remaining Contractual Life, Vested and exercisable | 7 years 8 months 23 days |
Weighted Average Remaining Contractual Life, Vested and expected to vest, Ending Balance | 8 years 2 months 1 day |
Aggregate Intrinsic Value | $ | $ 0 |
Aggregate Intrinsic Value, Vested and exercisable | $ | 0 |
Aggregate Intrinsic Value, Vested and expected to vest, Ending Balance | $ | $ 0 |
Stockholders' Equity - Addition
Stockholders' Equity - Additional Information (Detail) $ in Millions | 6 Months Ended |
Jun. 30, 2017USD ($) | |
Disclosure of Compensation Related Costs, Share-based Payments [Abstract] | |
Weighted average period for recognizing unrecognized compensation cost as expense | 2 years 4 months 24 days |
Unrecognized compensation cost related to stock option awards | $ 1.3 |
Stockholders' Equity - Weighted
Stockholders' Equity - Weighted-Average Assumptions (Detail) | 6 Months Ended | |
Jun. 30, 2017 | Jun. 30, 2016 | |
Disclosure of Compensation Related Costs, Share-based Payments [Abstract] | ||
Risk-free interest rate | 2.00% | 1.50% |
Expected life (years) | 6 years | 6 years |
Expected volatility | 88.00% | 89.00% |
Dividend yield | 0.00% | 0.00% |
Net Loss Per Share - Additional
Net Loss Per Share - Additional Information (Detail) - shares | 6 Months Ended | |
Jun. 30, 2017 | Jun. 30, 2016 | |
Stock Option [Member] | ||
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||
Common stock excluded from the calculation of weighted average shares for diluted net loss per share | 5,941,000 | 4,139,000 |
Warrants [Member] | ||
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||
Common stock excluded from the calculation of weighted average shares for diluted net loss per share | 9,626,000 | 9,842,000 |