Accounting Policies [Abstract] Accounting Policies [Abstract] Accounts Payable, Accrued Liabilities, and Other Liabilities Disclosure, Current [Text Block] Accrued Expenses and Other Current Liabilities Accounts Payable, Current Accounts payable Accretion (Amortization) of Discounts and Premiums, Investments Amortization and accretion of investments Accrued clinical costs current. Accrued Clinical Costs Current Accrued clinical costs Accrued Liabilities and Other Liabilities Accrued expenses and other current liabilities Total accrued expenses Accrued Professional Fees, Current Accrued professional fees Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Accumulated depreciation Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax Accumulated other comprehensive income AOCI Attributable to Parent [Member] Accumulated Other Comprehensive Income [Member] Additional Paid in Capital, Common Stock Additional paid-in capital Additional Paid-in Capital [Member] Additional Paid-In Capital [Member] Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition Stock-based compensation expense Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs Offering costs Adjustments to Additional Paid in Capital, Stock Split Repurchase of fractional shares resulting from reverse stock splits Adjustments to Additional Paid in Capital, Warrant Issued Reclassification of common stock warrant liability Reclassification of common stock warrant liability to additional paid-in capital Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Adjustments to reconcile net loss to net cash used in operating activities: Aggregate potential milestone payable. Aggregate Potential Milestone Payable Aggregate potential milestone payable Allocated Share-based Compensation Expense Share based compensation expense, total Amendment Flag Amendment Flag Amortization of Debt Issuance Costs and Discounts Amortization of debt discount and debt issuance costs Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Anti-dilutive securities excluded from computation of diluted net loss per common share Antidilutive Securities [Axis] Antidilutive Securities [Axis] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities, Name [Domain] Antidilutive Securities, Name [Domain] Area of Real Estate Property Area of property leased Arrangements and Non-arrangement Transactions [Domain] Arrangements and Non-arrangement Transactions [Domain] Assets Total assets Assets [Abstract] ASSETS Assets, Current Total current assets Assets, Current [Abstract] Current assets: Assets, Fair Value Disclosure Total assets Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax Unrealized Gains Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax Unrealized Losses Available-for-sale Debt Securities, Amortized Cost Basis Amortized Cost Available-for-sale Securities, Debt Securities Available for sale debt securities fair value Fair Value Available For Sale Securities Fair Value Disclosure [Abstract] Available For Sale Securities Fair Value Disclosure [Abstract] Available For Sale Securities Fair Value Disclosure [Abstract] Available-for-sale Securities, Gross Realized Gain (Loss) Realized gains or losses recognized on the sale or maturity of available-for-sale securities Available-for-sale Securities [Table Text Block] Summary of Available-for-Sale Securities Award Type [Axis] Award Type [Axis] Balance Sheet Location [Axis] Balance Sheet Location [Axis] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Bayer Pharma AG . Bayer Pharma AG [Member] Bayer Pharma AG [Member] Business Description and Basis of Presentation [Text Block] Basis of Presentation Capital Expenditures Incurred but Not yet Paid Property and equipment purchases included in accrued expenses Capital Leases, Future Minimum Payments Due Capital Lease Obligations, Total minimum lease payments Capital Lease Obligations, Total minimum lease payments Capital Leases, Future Minimum Payments Due, Next Twelve Months Capital Lease Obligations, 2017 Capital Leases, Future Minimum Payments Due in Five Years Capital Lease Obligations, 2021 Capital Leases, Future Minimum Payments Due in Four Years Capital Lease Obligations, 2020 Capital Leases, Future Minimum Payments Due in Three Years Capital Lease Obligations, 2019 Capital Leases, Future Minimum Payments Due in Two Years Capital Lease Obligations, 2018 Capital Leases, Future Minimum Payments Due Thereafter Capital Lease Obligations, 2022 and thereafter Capital Leases, Future Minimum Payments, Interest Included in Payments Capital Lease Obligations, Less amounts representing interest Capital Leases, Future Minimum Payments, Present Value of Net Minimum Payments Capital Lease Obligations, Present value of net minimum lease payments Reported Value Measurement [Member] Carrying Value [Member] Cash and Cash Equivalents, at Carrying Value CASH AND CASH EQUIVALENTS-end of year CASH AND CASH EQUIVALENTS-beginning of year Cash and cash equivalents Cash and Cash Equivalents [Axis] Cash and Cash Equivalents [Axis] Cash and Cash Equivalents, Fair Value Disclosure Cash equivalents Cash equivalents fair value Cash and Cash Equivalents, Period Increase (Decrease) NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS Cash and Cash Equivalents, Policy [Policy Text Block] Cash Equivalents Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block] Restricted Cash Cash Flow, Supplemental Disclosures [Text Block] Supplemental Cash Flow Information Class of Stock [Domain] Class of Stock [Domain] Class of Stock [Line Items] Class of Stock [Line Items] Class of Warrant or Right, Exercise Price of Warrants or Rights Average Exercise Price Warrant exercisable Class of Warrant or Right [Line Items] Class of Warrant or Right [Line Items] Class of Warrant or Right, Number of Securities Called by Warrants or Rights Shares of Common Stock Issuable Under the Warrant Total Shares of Common Stock Issuable Under the Warrant Class of Warrant or Right [Table] Class of Warrant or Right [Table] Clinical trial costs. Clinical Trial Costs [Policy Text Block] Clinical Trial Costs Clinical Trial [Member] Clinical Trial [Member] Clinical Trial [Member] Collaborative Arrangement [Member] Cost-Sharing Collaborations [Member] Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] Commercial Paper, Not Included with Cash and Cash Equivalents [Member] Commercial Paper [Member] Commitment And Contingencies [Line Items] Commitment And Contingencies [Line Items] Commitment And Contingencies [Line Items] Commitment And Contingencies [Table] Commitment And Contingencies [Table] Commitment And Contingencies [Table] Commitments and Contingencies Commitments (Note 16) Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Text Block] Commitments Common Stock, Capital Shares Reserved for Future Issuance Common stock reserved for future issuance Shares available for issuance Common stock disclosure. Common Stock Disclosure [Text Block] Common Stock Common stock issuable upon exercise of warrant. Common Stock Issuable Upon Exercise of Warrant Number of shares of common stock issuable upon exercise of the warrant Common Stock [Member] Common Stock [Member] Common Stock, Par or Stated Value Per Share Common stock, par value Common Stock, Shares Authorized Common stock, shares authorized Common Stock, Shares, Issued Common stock, shares issued Common Stock, Shares, Outstanding Common stock, shares outstanding Common Stock, Value, Issued Common stock, $0.0001 par value, 100,000,000 and 20,800,000 shares authorized; 18,215,181 and 85,440 shares outstanding at December 31, 2016 and December 31, 2015, respectively Common Stock Warrant Liability Common Stock Warrant Liability [Member] Common Stock Warrant Liability [Member] Common stock warrants. Common Stock Warrants [Policy Text Block] Common Stock Warrants Components of Deferred Tax Assets [Abstract] Components of Deferred Tax Assets [Abstract] Components of Deferred Tax Assets and Liabilities [Abstract] Deferred tax assets (liabilities): Comprehensive Income (Loss), Net of Tax, Attributable to Parent Comprehensive loss Office and computer equipment. Computer And Office Equipment [Member] Office and Computer Equipment [Member] Concentration Risk, Credit Risk, Policy [Policy Text Block] Concentrations of Credit Risk Consolidation, Policy [Policy Text Block] Principles of Consolidation Construction in Progress [Member] Construction in Progress [Member] Contractual Obligation Aggregate payment obligation Contractual obligations term. Contractual Obligations Term Period of contractual obligation Conversion of Stock, Amount Converted Conversion of preferred stock to common stock upon closing of initial public offering Convertible Debt Securities [Member] Convertible Notes and Related Accrued Interest [Member] Convertible Notes Payable [Member] Convertible Notes Payable [Member] Convertible Preferred Stock [Member] Convertible Preferred Stock [Member] Convertible preferred stock policy. Convertible Preferred Stock [Policy Text Block] Convertible Preferred Stock Convertible Preferred Stock, Shares Issued upon Conversion Conversion of convertible preferred stock to shares of common stock Convertible preferred stock converted in to common stock Corporate bonds and commercial paper. Corporate Bonds And Commercial Paper [Member] Corporate Bonds and Commercial Paper [Member] Corporate Debt Securities [Member] Corporate Bonds [Member] Costs related to cost sharing collaborations. Costs Related To Cost Sharing Collaborations External costs related to cost-sharing collaborations Counterparty Name [Axis] Counterparty Name [Axis] Current Fiscal Year End Date Current Fiscal Year End Date Debt Conversion, Converted Instrument, Amount Conversion of convertible notes and accrued interest into Series C-1 convertible preferred stock Debt Conversion, Converted Instrument, Shares Issued Debt instrument, number of shares converted Outstanding principal and related interest converted into shares Debt Disclosure [Abstract] Debt Disclosure [Abstract] Debt Disclosure [Text Block] Convertible Notes Debt instrument accrued interest. Debt Instrument Accrued Interest Accrued interest Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Basis Spread on Variable Rate Interest rate on term loan Debt Instrument, Convertible, Conversion Price Debt instrument, conversion price per share Debt Instrument, Description of Variable Rate Basis Description of interest rate on term loan Debt Instrument, Face Amount Debt instrument, aggregate principal amount Debt, principal amount Debt Instrument, Fee Amount Fee and prepayment penalty expenses recorded Debt instrument fee percentage. Debt Instrument Fee Percentage Effective fee on term loan Debt Instrument, Interest Rate, Stated Percentage Debt instrument, interest rate Debt Instrument [Line Items] Debt Instrument [Line Items] Debt Instrument, Maturity Date Debt instrument maturity date Debt instrument, maturity date Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Debt instrument prepayment fee percentage. Debt Instrument Prepayment Fee Percentage Prepayment fee percentage, if paid prior to the one-year anniversary Debt instrument prepayment fee percentage after year one. Debt Instrument Prepayment Fee Percentage After Year One Prepayment fee percentage, if paid after the one-year anniversary Debt Instruments [Abstract] Debt Instruments [Abstract] Debt instrument success fee. Debt Instrument Success Fee Success fee liability Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Debt instrument tranche one. Debt Instrument Tranche One [Member] First Closing [Member] Debt instrument tranche two Debt Instrument Tranche Two [Member] Second Closing [Member] Debt Instrument, Unamortized Discount Initial fair value of derivative recorded as debt discount Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net Unamortized debt discount and deferred issuance costs written off Debt Issuance Costs Incurred During Noncash or Partial Noncash Transaction Issuance costs included in accounts payable and accrued expenses Debt, Policy [Policy Text Block] Debt Discount Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract] Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract] Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Table Text Block] Schedule of Prepaid Expenses and Other Current Assets Debt Issuance Costs, Net Offering cost Debt Issuance Cost, Gross, Noncurrent Debt issuance cost incurred Deferred Offering Costs Capitalized deferred issuance costs Deferred Revenue Deferred revenue from license agreement Deferred Revenue, Current Current portion of deferred revenue Deferred Revenue, Noncurrent Deferred revenue, less current portion Deferred tax assets capitalized startup and costs research and development costs. Deferred Tax Assets Capitalized Startup And Costs Research And Development Costs Capitalized start-up and research and development costs Deferred Tax Assets, Deferred Income Deferred revenue Deferred Tax Assets, Gross Deferred tax assets before valuation allowance Deferred Tax Assets, in Process Research and Development Research and development credits Deferred Tax Assets, Net of Valuation Allowance Net deferred tax assets Deferred Tax Assets, Operating Loss Carryforwards Net operating loss carryforwards Deferred Tax Assets, Operating Loss Carryforwards, Domestic Federal net operating losses Deferred tax assets operating loss carryforwards expiration period. Deferred Tax Assets Operating Loss Carryforwards Expiration Period Operating loss carryforward expiration period Deferred Tax Assets, Operating Loss Carryforwards, State and Local State net operating losses Deferred Tax Assets, Other Other temporary differences Deferred Tax Assets, Tax Credit Carryforwards, Research Deferred tax assets research credits Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Accrued Liabilities Accruals Deferred Tax Assets, Valuation Allowance Valuation allowances Deferred Tax Liabilities Depreciation And Amortization Deferred Tax Liabilities Depreciation And Amortization Depreciation and amortization Defined Contribution Plan, Employer Discretionary Contribution Amount Contributions by the company Deposits Assets, Current Short-term deposits Depreciation Depreciation Derivative Liability, Fair Value, Gross Liability Fair Value of Warrant Liability Derivative liability Fair value of derivative Derivative Financial Instruments, Liabilities [Member] Derivative Liability [Member] Derivative Liability, Current Derivative liability Derivatives, Policy [Policy Text Block] Derivative Liabilities Description of Lessee Leasing Arrangements, Operating Leases Description of lease arrangements Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Stock-Based Compensation Document And Entity Information [Abstract] Document And Entity Information [Abstract] Document And Entity Information [Abstract] Document Fiscal Period Focus Document Fiscal Period Focus Document Fiscal Year Focus Document Fiscal Year Focus Document Period End Date Document Period End Date Document Type Document Type Domestic Tax Authority [Member] Federal [Member] Earnings Per Share [Abstract] Earnings Per Share [Abstract] Earnings Per Share, Basic and Diluted Net loss per share attributable to common stockholders-basic and diluted Net loss per share-basic and diluted Earnings Per Share [Text Block] Net Loss per Share Attributable to Common Stockholders Eastern Cooperative Oncology Group. Eastern Cooperative Oncology Group [Member] Eastern Cooperative Oncology Group [Member] Employee-related Liabilities, Current Accrued compensation and related costs Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition Weighted average period to recognize compensation expense Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options Unrecognized compensation expense related to stock option Employee Stock Option [Member] Options to Purchase Common Stock [Member] Employee stock purchase plan. Employee Stock Purchase Plan [Member] Employee Stock Purchase Plan [Member] Entity Central Index Key Entity Central Index Key Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Entity Current Reporting Status Entity Current Reporting Status Entity Filer Category Entity Filer Category Entity Public Float Entity Public Float Entity Registrant Name Entity Registrant Name Entity Voluntary Filers Entity Voluntary Filers Entity Well-known Seasoned Issuer Entity Well-known Seasoned Issuer Equity [Abstract] Equity [Abstract] Equity Component [Domain] Equity Component [Domain] Fair Value Adjustment of Warrants Change in fair value of warrants Change in fair value Change in fair value of common stock warrant liability Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Table Text Block] Grant Date Fair Values of Options Issued to Employees and Non-employees Estimated Using Black-Scholes Option Pricing Model Fair Value Assumptions and Methodology for Assets and Liabilities [Abstract] Fair Value Assumptions and Methodology for Assets and Liabilities [Abstract]