Debt	9 Months Ended
Sep. 30, 2014
Debt [Abstract]
Debt	10. Debt *Square 1 Bank Loan* In August 2014, the Company entered into a secured loan with Square 1 Bank ("Loan"). The Loan provides the Company with a term loan in the aggregate principal amount not to exceed $7,500,000 to be used to supplement working capital. The Loan is available to the Company in four tranches: $1,500,000 was made available to the Company on August 22, 2014 (“Tranche 1 Loan”), $1,500,000 became available to the Company upon its enrollment of its first patient in its the Phase 2 clinical trial for HS-110 (“Tranche 2 Loan ”), $2,250,000 will be available to the Company upon Square 1 Bank's receipt or before June 30, 2015 of evidence satisfactory to it of the initiation and continuation of the ImPACT cell line for a third indication (“Tranche 3 Loan”) and $2,250,000 will be available to the Company upon Square 1 Bank's receipt or before October 31, 2015 of evidence satisfactory to it of the full enrollment of our Phase 1/2 clinical trial for HS -410 (“Tranche 4 Loan”). As of September 30, 2014, the Company had drawn down $1,500,000 under the Tranche 1 Loan. On October 27, 2014, the Company met the milestone required to draw down the Tranche 2 Loan but has not yet requested a draw down. The Loan accrues interest monthly at an interest rate of 3.05% plus prime or 6.30 % per annum whichever is greater. The Tranche 1 Loan is payable as interest-only until June 30, 2015 since the Company has already achieved the Tranche 2 milestone and thereafter interest is payable in monthly installments of principal plus accrued interest until February 22, 2018. The Tranche 2 Loan is available prior to December 31, 2014 and is payable as interest-only prior to June 30, 2015 (unless the Company achieves the Tranche 3 milestone at which time the interest only period will be extended until October 31, 2015) and thereafter is payable in monthly installments of principal plus accrued interest until February 22, 2018. The Tranche 3 Loan is available until June 30, 2015 and is payable as interest-only prior to October 31, 2015 and thereafter is payable in monthly installments of principal plus accrued interest until February 22, 2018. The Tranche 4 Loan is available until October 31, 2015 and is payable in monthly installments of principal plus accrued interest until February 22, 2018. As of September 30, 2014, the Company has made $0 in principal payments and $8,138 in interest payments on the outstanding loan. The agreement with Square 1 Bank sets forth various affirmative and negative covenants. The failure of the Company to comply with the covenants constitutes a default under the Loan. The covenants include the Company having at least two ongoing clinical trials at all times, the attainment of the funding conditions set forth in the agreement and covenants regarding financial reporting, limits on the Company's cash burn, incurrence of indebtedness, permitted investments, encumbrances, distributions, investments and mergers and acquisitions. The Loan is also secured by a security interest in all of the Company's personal property, excluding its intellectual property. In connection with the Loan, in August 2014, the Company issued Square 1 Bank a warrant, exercisable for 52,695 shares of the Company's common stock at an exercise price of $4.27. In accordance with ASC 480-10, Distinguishing Liabilities from Equity, the freestanding warrant for the Company's common stock was recognized as a liability and recorded at fair value in all periods prior to exercise. The warrant liability was re-measured to fair value prior to reclassification to additional paid in capital upon its exercise. The initial fair value of the warrant of $323,021 was recorded as a liability and a discount to notes payable and is being amortized to interest expense over the term of the Loan. In September 2014, the warrants were exercised via a cashless exercise into 17,664 shares of the Company's common stock. The fair value of the warrants is shown as a debt discount and is netted against the outstanding loan balance in the condensed consolidated balance sheets.

10. Debt

Square 1 Bank Loan

In August 2014, the Company entered into a secured loan with Square 1 Bank ("Loan"). The Loan provides the Company with a term loan in the aggregate principal amount not to exceed $7,500,000 to be used to supplement working capital. The Loan is available to the Company in four tranches: $1,500,000 was made available to the Company on August 22, 2014 (“Tranche 1 Loan”), $1,500,000 became available to the Company upon its enrollment of its first patient in its the Phase 2 clinical trial for HS-110 (“Tranche 2 Loan ”), $2,250,000 will be available to the Company upon Square 1 Bank's receipt or before June 30, 2015 of evidence satisfactory to it of the initiation and continuation of the ImPACT cell line for a third indication (“Tranche 3 Loan”) and $2,250,000 will be available to the Company upon Square 1 Bank's receipt or before October 31, 2015 of evidence satisfactory to it of the full enrollment of our Phase 1/2 clinical trial for HS -410 (“Tranche 4 Loan”). As of September 30, 2014, the Company had drawn down $1,500,000 under the Tranche 1 Loan. On October 27, 2014, the Company met the milestone required to draw down the Tranche 2 Loan but has not yet requested a draw down.

The Loan accrues interest monthly at an interest rate of 3.05% plus prime or 6.30 % per annum whichever is greater. The Tranche 1 Loan is payable as interest-only until June 30, 2015 since the Company has already achieved the Tranche 2 milestone and thereafter interest is payable in monthly installments of principal plus accrued interest until February 22, 2018. The Tranche 2 Loan is available prior to December 31, 2014 and is payable as interest-only prior to June 30, 2015 (unless the Company achieves the Tranche 3 milestone at which time the interest only period will be extended until October 31, 2015) and thereafter is payable in monthly installments of principal plus accrued interest until February 22, 2018. The Tranche 3 Loan is available until June 30, 2015 and is payable as interest-only prior to October 31, 2015 and thereafter is payable in monthly installments of principal plus accrued interest until February 22, 2018. The Tranche 4 Loan is available until October 31, 2015 and is payable in monthly installments of principal plus accrued interest until February 22, 2018. As of September 30, 2014, the Company has made $0 in principal payments and $8,138 in interest payments on the outstanding loan. The agreement with Square 1 Bank sets forth various affirmative and negative covenants. The failure of the Company to comply with the covenants constitutes a default under the Loan. The covenants include the Company having at least two ongoing clinical trials at all times, the attainment of the funding conditions set forth in the agreement and covenants regarding financial reporting, limits on the Company's cash burn, incurrence of indebtedness, permitted investments, encumbrances, distributions, investments and mergers and acquisitions. The Loan is also secured by a security interest in all of the Company's personal property, excluding its intellectual property.

In connection with the Loan, in August 2014, the Company issued Square 1 Bank a warrant, exercisable for 52,695 shares of the Company's common stock at an exercise price of $4.27. In accordance with ASC 480-10, Distinguishing Liabilities from Equity, the freestanding warrant for the Company's common stock was recognized as a liability and recorded at fair value in all periods prior to exercise. The warrant liability was re-measured to fair value prior to reclassification to additional paid in capital upon its exercise. The initial fair value of the warrant of $323,021 was recorded as a liability and a discount to notes payable and is being amortized to interest expense over the term of the Loan. In September 2014, the warrants were exercised via a cashless exercise into 17,664 shares of the Company's common stock. The fair value of the warrants is shown as a debt discount and is netted against the outstanding loan balance in the condensed consolidated balance sheets.