Annual report pursuant to Section 13 and 15(d)

Statements of Cash Flows

v2.4.1.9
Statements of Cash Flows (USD $)
 12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Operating activities:    
Net loss $ (49,700,875)us-gaap_NetIncomeLoss $ (23,251,435)us-gaap_NetIncomeLoss
Adjustments to reconcile net loss to net cash used in operating activities:    
Depreciation and amortization 239,390us-gaap_DepreciationDepletionAndAmortization 706,779us-gaap_DepreciationDepletionAndAmortization
Stock-based compensation 2,383,399us-gaap_ShareBasedCompensation 927,996us-gaap_ShareBasedCompensation
Noncash interest expense on loans 33,442us-gaap_PaidInKindInterest 121,160us-gaap_PaidInKindInterest
Loss on disposal of assets 5,015us-gaap_GainLossOnDispositionOfAssets1  
Revaluation of warrant liability (122,412)us-gaap_FairValueAdjustmentOfWarrants (241,478)us-gaap_FairValueAdjustmentOfWarrants
Changes in operating assets and liabilities:    
Prepaid expenses, offering costs and other assets 3,196,559us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets (3,667,605)us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets
Accounts payable and other liabilities 4,187,552us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities 1,165,353us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities
Net cash used in operating activities (39,777,930)us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations (24,239,230)us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations
Investing activities:    
Purchase of property and equipment (440,381)us-gaap_PaymentsToAcquirePropertyPlantAndEquipment (140,036)us-gaap_PaymentsToAcquirePropertyPlantAndEquipment
Purchase of marketable securities (70,717,422)us-gaap_PaymentsToAcquireMarketableSecurities  
Net cash used in investing activities (71,157,803)us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperations (140,036)us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperations
Financing activities:    
Proceeds from issuance of redeemable convertible preferred stock and warrants, net   59,918,917us-gaap_ProceedsFromIssuanceOfConvertiblePreferredStock
Proceeds from exercise of common stock options 111,778us-gaap_ProceedsFromStockOptionsExercised 83,555us-gaap_ProceedsFromStockOptionsExercised
Proceeds from exercise of preferred stock warrants   550,000us-gaap_ProceedsFromWarrantExercises
Proceeds from loans payable 1,775,012us-gaap_ProceedsFromIssuanceOfDebt  
Proceeds from issuance of common stock, net 107,290,323us-gaap_ProceedsFromIssuanceOfCommonStock  
Repayment of loans payable   (4,946,667)us-gaap_RepaymentsOfDebt
Capital lease payments (1,019)us-gaap_RepaymentsOfLongTermCapitalLeaseObligations  
Net cash provided by financing activities 109,176,094us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperations 55,605,805us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperations
Net increase (decrease) in cash and cash equivalents (1,759,639)us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease 31,226,539us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease
Cash and cash equivalents, beginning of period 37,965,198us-gaap_CashAndCashEquivalentsAtCarryingValue 6,738,659us-gaap_CashAndCashEquivalentsAtCarryingValue
Cash and cash equivalents-end of period 36,205,559us-gaap_CashAndCashEquivalentsAtCarryingValue 37,965,198us-gaap_CashAndCashEquivalentsAtCarryingValue
Supplemental disclosure of cash flow information:    
Cash paid for interest 37,209us-gaap_InterestPaid 85,422us-gaap_InterestPaid
Capital lease additions 14,259us-gaap_CapitalLeaseObligationsIncurred  
Common Stock    
Supplemental disclosure of cash flow information:    
Fair value of stock warrants issued $ 1,000us-gaap_StockIssued1
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonStockMember