Entity Central Index Key Document and entity information. Document And Entity Information [Abstract] Document Type Document Type Amendment Flag Amendment Flag Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Trading Symbol Trading Symbol Entity Registrant Name Entity Registrant Name Entity Central Index Key Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Entity Common Stock, Shares Outstanding Entity Common Stock Shares Outstanding Accounts receivable prepaid expense and other current assets. Statement Of Financial Position [Abstract] ASSETS Assets [Abstract] Current assets: Assets Current [Abstract] Cash and cash equivalents Cash And Cash Equivalents At Carrying Value Accounts receivable, prepaid expenses, and other current assets Accounts Receivable Prepaid Expense And Other Current Assets Total current assets Assets Current Property and equipment, net Property Plant And Equipment Net Other assets Other Assets Noncurrent Total assets Assets LIABILITIES AND STOCKHOLDERS’ EQUITY Liabilities And Stockholders Equity [Abstract] Current liabilities: Liabilities Current [Abstract] Accounts payable Accounts Payable Current Accrued expenses Accrued Liabilities Current Current portion of loan payable Loans Payable Current Current portion deferred revenue Deferred Revenue Current Total current liabilities Liabilities Current Long-term liabilities: Liabilities Noncurrent [Abstract] Loan payable, net of current portion Long Term Loans Payable Deferred revenue Deferred Revenue Noncurrent Other long-term liabilities Other Liabilities Noncurrent Total long-term liabilities Liabilities Noncurrent Commitments and contingencies Commitments And Contingencies Stockholders’ equity: Stockholders Equity [Abstract] Preferred stock $0.01 par value; 5,000,000 shares authorized, no shares issued or outstanding Preferred Stock Value Common stock, $0.0001 par value; 120,000,000 shares authorized, 2,903,172 and 2,893,718 shares issued and outstanding at June 30, 2017 and December 31, 2016, respectively Common Stock Value Additional paid-in capital Additional Paid In Capital Common Stock Accumulated deficit Retained Earnings Accumulated Deficit Total stockholders’ equity Stockholders Equity Total liabilities and stockholders’ equity Liabilities And Stockholders Equity Preferred stock, par value Preferred Stock Par Or Stated Value Per Share Preferred stock, shares authorized Preferred Stock Shares Authorized Preferred stock, shares issued Preferred Stock Shares Issued Preferred stock, shares outstanding Preferred Stock Shares Outstanding Common stock, par value Common Stock Par Or Stated Value Per Share Common stock, shares authorized Common Stock Shares Authorized Common stock, shares issued Common Stock Shares Issued Common stock, shares outstanding Common Stock Shares Outstanding Income Statement [Abstract] Revenue Revenues Operating expenses: Operating Expenses [Abstract] Research and development Research And Development Expense General and administrative General And Administrative Expense Gain on asset sale Gains Losses On Sales Of Assets Total operating expenses Operating Expenses Other income (expense): Nonoperating Income Expense [Abstract] Interest income Investment Income Interest Interest expense Interest Expense Other income (expense) Other Nonoperating Income Expense Total other expense, net Nonoperating Income Expense Net loss attributable to common stockholders Net Income Loss Net loss per share attributable to common stockholders: Earnings Per Share Basic And Diluted [Abstract] Basic and diluted Earnings Per Share Basic And Diluted Weighted-average common shares outstanding: Weighted Average Number Of Shares Outstanding [Abstract] Basic and diluted Weighted Average Number Of Share Outstanding Basic And Diluted Increase decrease in accounts receivable prepaid expenses and other current assets. Payment end term charge on loan payable. Statement Of Cash Flows [Abstract] Cash flows from operating activities: Net Cash Provided By Used In Operating Activities Continuing Operations [Abstract] Net loss Adjustments to reconcile net loss to net cash used in operating activities: Adjustments To Reconcile Net Income Loss To Cash Provided By Used In Operating Activities [Abstract] Stock-based compensation Share Based Compensation Noncash rent expense Straight Line Rent Adjustments Depreciation and amortization Depreciation Depletion And Amortization Amortization of debt discount and deferred financing costs Amortization Of Financing Costs And Discounts Loss on disposal of property and equipment Gain Loss On Sale Of Property Plant Equipment Deferred revenue Increase Decrease In Deferred Revenue Changes in operating assets and liabilities: Increase Decrease In Operating Capital [Abstract] Accounts receivable, prepaid expenses and other current assets Increase Decrease In Accounts Receivable Prepaid Expenses And Other Current Assets Accounts payable Increase Decrease In Accounts Payable Accrued expenses Increase Decrease In Accrued Liabilities Net cash used in operating activities Net Cash Provided By Used In Operating Activities Continuing Operations Cash flows from investing activities: Net Cash Provided By Used In Investing Activities Continuing Operations [Abstract] Purchases of property and equipment Payments To Acquire Property Plant And Equipment Decrease in restricted cash Increase Decrease In Restricted Cash Proceeds from the sale of assets Proceeds From Sale Of Productive Assets Net cash provided by (used in) investing activities Net Cash Provided By Used In Investing Activities Continuing Operations Cash flows from financing activities: Net Cash Provided By Used In Financing Activities Continuing Operations [Abstract] Proceeds from sale of common stock Proceeds From Issuance Of Common Stock Payments on loan payable Repayments Of Notes Payable Payment of end of term charge on loan payable Payment End Term Charge On Loan Payable Net cash used in financing activities Net Cash Provided By Used In Financing Activities Continuing Operations Net decrease in cash and cash equivalents Cash And Cash Equivalents Period Increase Decrease Cash and cash equivalents — Beginning of period Cash and cash equivalents — End of period Supplemental cash flow information — Interest paid Interest Paid Net Organization Consolidation And Presentation Of Financial Statements [Abstract] Nature of Business and Operations Nature Of Operations Accounting Policies [Abstract] Significant Accounting Policies Significant Accounting Policies [Text Block] Earnings Per Share [Abstract] Net Loss Per Share Attributable to Common Stockholders Earnings Per Share [Text Block] Property Plant And Equipment [Abstract] Property and Equipment Property Plant And Equipment Disclosure [Text Block] Payables And Accruals [Abstract] Accrued Expenses Accounts Payable And Accrued Liabilities Disclosure [Text Block] Debt Disclosure [Abstract] Loan Agreements Long Term Debt [Text Block] Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] Stock-Based Compensation Disclosure Of Compensation Related Costs Share Based Payments [Text Block] Fair Value Disclosures [Abstract] Fair Value Measurements Fair Value Disclosures [Text Block] Research And Development [Abstract] Revenue Research Development And Computer Software Disclosure [Text Block] Restructuring And Related Activities [Abstract] Restructuring Restructuring And Related Activities Disclosure [Text Block] Subsequent Events [Abstract] Subsequent Events Subsequent Events [Text Block] Recent Accounting Pronouncements New Accounting Pronouncements Policy Policy [Text Block] Potentially Dilutive Securities Excluded from Computation of Diluted Weighted-Average Shares Outstanding Schedule Of Antidilutive Securities Excluded From Computation Of Earnings Per Share [Text Block] Summary of Property and Equipment Property Plant And Equipment [Text Block] Schedule of Accrued Expenses Schedule Of Accrued Liabilities Table [Text Block] Statement [Table] Statement [Table] Award Type Award Type [Axis] Equity Award Share Based Compensation Arrangements By Share Based Payment Award Award Type And Plan Name [Domain] Non employee awards. Non Employee Awards [Member] Non Employee Awards [Member] Statement [Line Items] Statement [Line Items] Summary of Stock Option Activity for Employee, Director and Nonemployee Awards Schedule Of Share Based Compensation Stock Options Activity Table [Text Block] Summary of Assumptions Used in Black-Scholes Option-Pricing Model for Stock Options Granted to Employees, Directors and Non Employees Schedule Of Share Based Payment Award Stock Options Valuation Assumptions Table [Text Block] Summary of Financial Assets and Liabilities Measured on Recurring Basis at Fair Value Schedule Of Fair Value Assets And Liabilities Measured On Recurring Basis Table [Text Block] Stock purchase agreement date. Stock purchase and other transactions completion date. Nature of business and operations. Nature of business and operations. Nature Of Business And Operations [Table] Nature Of Business And Operations [Table] Subsequent Event Type Subsequent Event Type [Axis] Subsequent Event Type Subsequent Event Type [Domain] Subsequent Events [Member] Subsequent Event [Member] Legal Entity Legal Entity [Axis] Entity Entity [Domain] Novartis Institutes for Bio-Medical Research, Inc. Novartis Institutes for BioMedical Research, Inc [Member] Novartis Institutes For Bio Medical Research Inc [Member] Type of Arrangement and Non-arrangement Transactions Type Of Arrangement [Axis] Arrangements and Non-arrangement Transactions Arrangements And Nonarrangement Transactions [Member] Asset purchase agreement. Asset Purchase Agreement [Member] Asset Purchase Agreement [Member] Nature Of Business And Operations [Line Items] Nature Of Business And Operations [Line Items] Stock purchase agreement date Stock Purchase Agreement Date Stock purchase transaction completion date Stock Purchase And Other Transactions Completion Date Proceeds from sale of assets Proceeds From Sale Of Intangible Assets Term of planned operations. Existing resources sufficient to fund planned operations, term Term Of Planned Operations Reverse stock split description Stockholders Equity Reverse Stock Split Reverse stock split ratio Stockholders Equity Note Stock Split Conversion Ratio1 Schedule Of Antidilutive Securities Excluded From Computation Of Earnings Per Share [Table] Schedule Of Antidilutive Securities Excluded From Computation Of Earnings Per Share [Table] Antidilutive Securities Antidilutive Securities Excluded From Computation Of Earnings Per Share By Antidilutive Securities [Axis] Antidilutive Securities, Name Antidilutive Securities Name [Domain] Options to purchase common stock. Options to Purchase Common Stock [Member] Options To Purchase Common Stock [Member] Warrants [Member] Warrant [Member] Equity Components Statement Equity Components [Axis] Equity Component Equity Component [Domain] Common Stock [Member] Common Stock [Member] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] Antidilutive securities excluded from computation of diluted weighted-average shares outstanding Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount Schedule Of Property Plant And Equipment [Table] Schedule Of Property Plant And Equipment [Table] Property, Plant and Equipment, Type Property Plant And Equipment By Type [Axis] Property, Plant and Equipment, Type Property Plant And Equipment Type [Domain] Laboratory Equipment [Member] Equipment [Member] Computer Equipment [Member] Computer Equipment [Member] Office Furniture and Equipment [Member] Office Equipment [Member] Leasehold Improvements [Member] Leasehold Improvements [Member] Property, Plant and Equipment [Line Items] Property Plant And Equipment [Line Items] Property and equipment, gross Property Plant And Equipment Gross Less accumulated depreciation and amortization Accumulated Depreciation Depletion And Amortization Property Plant And Equipment Property and equipment, net Lease termination agreement date. Disposal Group Classification Disposal Group Classification [Axis] Disposal Group Classification Disposal Group Classification [Domain] Discontinued Operations, Held-for-sale [Member] Discontinued Operations Heldforsale [Member] Income Statement Location Income Statement Location [Axis] Income Statement Location Income Statement Location [Domain] Other Expense [Member] Other Expense [Member] Charges for disposal of property and equipment Lease termination agreement date Lease Termination Agreement Date Accrued clinical trial costs current. Accrued manufacturing expenses current. Accrued clinical trial costs Accrued Clinical Trial Costs Current Accrued contract manufacturing expenses Accrued Manufacturing Expenses Current Accrued compensation and benefits Employee Related Liabilities Current Accrued interest Interest Payable Current Other accrued expenses Other Accrued Liabilities Current Total accrued expenses Extinguishment of debt final end of term charge amount. Debt final payment percentage of aggregate principal amount. Extinguishment of debt accrued final end of term charge amount. Debt Instrument [Table] Debt Instrument [Table] Debt Instrument Debt Instrument [Axis] Debt Instrument, Name Debt Instrument Name [Domain] Hercules loan agreement. Hercules Loan Agreement [Member] Hercules Loan Agreement [Member] Lender Name Line Of Credit Facility [Axis] Line of Credit Facility, Lender Line Of Credit Facility Lender [Domain] Hercules Technology Growth Capital, Incorporation. Hercules Technology Growth Capital, Inc. [Member] Hercules Technology Growth Capital Inc [Member] Long-term Debt, Type Longterm Debt Type [Axis] Long-term Debt, Type Longterm Debt Type [Domain] Loans Payable [Member] Loans Payable [Member] Debt Instrument [Line Items] Debt Instrument [Line Items] Loan and security agreement, maximum borrowing capacity Line Of Credit Facility Maximum Borrowing Capacity Pay off loan agreement, amount paid Extinguishment Of Debt Amount Pay off loan agreement, final end of term charge amount Extinguishment Of Debt Final End Of Term Charge Amount Final payment as percentage of aggregate original principal amount Debt Final Payment Percentage Of Aggregate Principal Amount Amount outstanding under the loan and security agreement Loans Payable Accrued end of term charge Extinguishment Of Debt Accrued Final End Of Term Charge Amount Exercise price of warrant Class Of Warrant Or Right Exercise Price Of Warrants Or Rights1 Warrant to purchase stock, number of securities called by warrants or rights Class Of Warrant Or Right Number Of Securities Called By Warrants Or Rights Class of warrant or right, date until which warrants exercisable Class Of Warrant Or Righst Date From Which Warrants Or Rights Exercisable