Equity	12 Months Ended
Dec. 31, 2019
Equity [Abstract]
Equity	(9) Equity Effective June 19, 2019, our certificate of incorporation was amended to increase the number of authorized shares of common stock from 240,000,000 to 400,000,000. Under the terms and conditions of the Certificate of Designation creating the Series A-1 Preferred Stock, this stock is convertible by the holder at any time into our common stock, is non-voting, has an initial conversion price of $94.86 per common share, subject to adjustment, and is redeemable by us at its face amount ($31.6 million), plus any accrued and unpaid dividends. The Certificate of Designation does not contemplate a sinking fund. The Series A-1 Preferred Stock ranks senior to both our Series C-1 Convertible Preferred Stock and our common stock. In a liquidation, dissolution, or winding up of the Company, the Series A-1 Preferred Stock’s liquidation preference must be fully satisfied before any distribution could be made to the holders of the common stock. Other than in such a liquidation, no terms of the Series A-1 Preferred Stock affect our ability to declare or pay dividends on our common stock as long as the Series A-1 Preferred Stock’s dividends are accruing. The liquidation value of this Series A-1 Preferred stock is equal to $1,000 per share outstanding plus any accrued unpaid dividends. Dividends in arrears with respect to the Series A-1 Preferred Stock were approximately $1.4 million or $44.92 per share, and $1.2 million, or $38.33 per share, at December 31, 2019 and 2018, respectively. During September 2013, we sold approximately 3,333,000 shares of our common stock and warrants to purchase 1,000,000 shares of our common stock in a registered direct public offering raising net proceeds of approximately $9.5 million, after deducting offering expenses. The common stock and warrants were sold in units, with each unit consisting of one share of common stock and a warrant to purchase 0.3 of a share of common stock. Subject to certain ownership limitations, the warrants became exercisable beginning 6 months following issuance and will expire five years from the date they become exercisable, at an exercise price of $3.75 per share. The number of shares issuable upon exercise of the warrants and the exercise price of the warrants are adjustable in the event of stock splits, stock dividends, combinations of shares and similar recapitalization transactions. The warrants expired unexercised in March 2019. On February 14, 2017, we entered into an additional Stock Purchase Agreement (the “Additional Stock Purchase Agreement”) with Incyte, pursuant to which Incyte purchased 10 million shares of our common stock (the “Additional Shares”) at a purchase price of $6.00 per share. Immediately following the transaction, Incyte owned approximately 18.1% of our outstanding shares. Under the Additional Stock Purchase Agreement, Incyte agreed not to dispose of any of the Additional Shares for a period of 12 months and to vote the Additional Shares in accordance with the recommendations of the Company’s board of directors in connection with certain equity incentive plan or compensation matters for a period of 18 months, both provisions have expired. We also agreed to certain registration rights with respect to the Additional Shares. The parties also revised the existing standstill provision to permit Incyte’s acquisition of the Additional Shares, but Incyte was precluded from acquiring any additional shares of our voting stock until December 31, 2019. In March 2017, we issued an additional 373,351 shares of our common stock, valued at approximately $1.5 million, to Iontas in accordance with the terms of the Technology Transfer and License Agreement. Subsequently, we filed, and the SEC declared effective, a registration statement covering the resale of the 530,864 shares of our common stock issued. On November 9, 2017 we made the final payment under the Asset Purchase Agreement with Celexion, LLC (“Celexion”) and each of the members of Celexion. We issued to Celexion 999,317 shares of our common stock based on the preceding 20 trading day average of approximately $4.10 per share. The closing price of our common stock on November 9, 2017 was $3.55 per share. As such, we recorded a gain of approximately $550,000 at issuance. Also, on November 9, 2017, we filed a registration statement covering the sale of the 999,317 shares issued to Celexion. The SEC declared the registration statement effective in January 2018. In October 2017, we filed, and the SEC declared effective, a Registration Statement on Form S-3 (the “2017 Registration Statement”), covering the offering of up to $250 million of common stock, preferred stock, warrants, debt securities and units. The 2017 Registration Statement included a prospectus covering the offering, issuance and sale of up to 15 million shares of our common stock from time to time in “at-the-market offerings” pursuant to a Controlled Equity Offering^SM sales agreement (the “Sales Agreement”) entered into with Cantor Fitzgerald & Co. (the “Sales Agent”) on October 30, 2017. Pursuant to the Sales Agreement, sales will be made only upon instructions by us to the Sales Agent, and we cannot provide any assurances that it will issue any shares pursuant to the Sales Agreement. On October 18, 2017, we exercised our right under that certain At Market Issuance Sales Agreement by and between us and MLV & Co. LLC, dated as of October 10, 2014 (the “2014 ATM Program”) to terminate the 2014 ATM Program, which termination took effect upon the effectiveness of the 2017 Registration Statement. We terminated the Sales Agreement with Cantor Fitzgerald & Co. in May 2018. In May 2018, we entered into an At Market Issuance Sales Agreement (the “Agreement”) with B. Riley FBR, Inc. (“BRFBR”) with respect to an at-the-market offering program under which we may offer and sell, from time to time at our sole discretion, up to 20 million shares of our common stock through BRFBR as our sales agent. The issuance and sale of the shares under the Agreement are made pursuant to our 2017 Registration Statement. In December 2018, we filed a prospectus supplement with the SEC in connection with the offer and sale of up to an additional 30 million shares from time to time pursuant to the Agreement. During the year ended December 31, 2019, no shares of our common stock were sold in at-the-market offerings under the Agreement. On December 20, 2018, in connection of the Gilead Collaboration Agreement we also entered into the Stock Purchase Agreement (the “Gilead Stock Purchase Agreement”) with Gilead Sciences, Inc. (“Gilead”), pursuant to which Gilead purchased approximately 11.11 million shares of our common stock (the “Shares”) for an aggregate purchase price of $30.0 million, or $2.70 per Share. Gilead owned approximately 8.5% of the outstanding shares of our common stock after such purchase. Under the Stock Purchase Agreement, Gilead has agreed (i) not to dispose of any of the Shares for a period of 12 months, (ii) to certain standstill provisions that generally preclude it from acquiring more than 15% of our outstanding voting stock after taking into account the purchase of the Shares and (iii) to vote the Shares in accordance with the recommendations of our board of directors in connection with certain equity incentive plan or compensation matters for a period of 12 months. In the Gilead Stock Purchase Agreement, we agreed to register the Shares for resale under the Securities Act of 1933, and in October 2019 we filed a registration statement with the SEC accordingly.

Equity

12 Months Ended

Dec. 31, 2019

(9) Equity

Effective June 19, 2019, our certificate of incorporation was amended to increase the number of authorized shares of common stock from 240,000,000 to 400,000,000.

Under the terms and conditions of the Certificate of Designation creating the Series A-1 Preferred Stock, this stock is convertible by the holder at any time into our common stock, is non-voting, has an initial conversion price of $94.86 per common share, subject to adjustment, and is redeemable by us at its face amount ($31.6 million), plus any accrued and unpaid dividends. The Certificate of Designation does not contemplate a sinking fund. The Series A-1 Preferred Stock ranks senior to both our Series C-1 Convertible Preferred Stock and our common stock. In a liquidation, dissolution, or winding up of the Company, the Series A-1 Preferred Stock’s liquidation preference must be fully satisfied before any distribution could be made to the holders of the common stock. Other than in such a liquidation, no terms of the Series A-1 Preferred Stock affect our ability to declare or pay dividends on our common stock as long as the Series A-1 Preferred Stock’s dividends are accruing. The liquidation value of this Series A-1 Preferred stock is equal to $1,000 per share outstanding plus any accrued unpaid dividends. Dividends in arrears with respect to the Series A-1 Preferred Stock were approximately $1.4 million or $44.92 per share, and $1.2 million, or $38.33 per share, at December 31, 2019 and 2018, respectively.

During September 2013, we sold approximately 3,333,000 shares of our common stock and warrants to purchase 1,000,000 shares of our common stock in a registered direct public offering raising net proceeds of approximately $9.5 million, after deducting offering expenses. The common stock and warrants were sold in units, with each unit consisting of one share of common stock and a warrant to purchase 0.3 of a share of common stock. Subject to certain ownership limitations, the warrants became exercisable beginning 6 months following issuance and will expire five years from the date they become exercisable, at an exercise price of $3.75 per share. The number of shares issuable upon exercise of the warrants and the exercise price of the warrants are adjustable in the event of stock splits, stock dividends, combinations of shares and similar recapitalization transactions. The warrants expired unexercised in March 2019.

On February 14, 2017, we entered into an additional Stock Purchase Agreement (the “Additional Stock Purchase Agreement”) with Incyte, pursuant to which Incyte purchased 10 million shares of our common stock (the “Additional Shares”) at a purchase price of $6.00 per share. Immediately following the transaction, Incyte owned approximately 18.1% of our outstanding shares. Under the Additional Stock Purchase Agreement, Incyte agreed not to dispose of any of the Additional Shares for a period of 12 months and to vote the Additional Shares in accordance with the recommendations of the Company’s board of directors in connection with certain equity incentive plan or compensation matters for a period of 18 months, both provisions have expired. We also agreed to certain registration rights with respect to the Additional Shares. The parties also revised the existing standstill provision to permit Incyte’s acquisition of the Additional Shares, but Incyte was precluded from acquiring any additional shares of our voting stock until December 31, 2019.

In March 2017, we issued an additional 373,351 shares of our common stock, valued at approximately $1.5 million, to Iontas in accordance with the terms of the Technology Transfer and License Agreement. Subsequently, we filed, and the SEC declared effective, a registration statement covering the resale of the 530,864 shares of our common stock issued.

On November 9, 2017 we made the final payment under the Asset Purchase Agreement with Celexion, LLC (“Celexion”) and each of the members of Celexion. We issued to Celexion 999,317 shares of our common stock based on the preceding 20 trading day average of approximately $4.10 per share. The closing price of our common stock on November 9, 2017 was $3.55 per share. As such, we recorded a gain of approximately $550,000 at issuance. Also, on November 9, 2017, we filed a registration statement covering the sale of the 999,317 shares issued to Celexion. The SEC declared the registration statement effective in January 2018.

In October 2017, we filed, and the SEC declared effective, a Registration Statement on Form S-3 (the “2017 Registration Statement”), covering the offering of up to $250 million of common stock, preferred stock, warrants, debt securities and units. The 2017 Registration Statement included a prospectus covering the offering, issuance and sale of up to 15 million shares of our common stock from time to time in “at-the-market offerings” pursuant to a Controlled Equity Offering^SM sales agreement (the “Sales Agreement”) entered into with Cantor Fitzgerald & Co. (the “Sales Agent”) on October 30, 2017. Pursuant to the Sales Agreement, sales will be made only upon instructions by us to the Sales Agent, and we cannot provide any assurances that it will issue any shares pursuant to the Sales Agreement. On October 18, 2017, we exercised our right under that certain At Market Issuance Sales Agreement by and between us and MLV & Co. LLC, dated as of October 10, 2014 (the “2014 ATM Program”) to terminate the 2014 ATM Program, which termination took effect upon the effectiveness of the 2017 Registration Statement. We terminated the Sales Agreement with Cantor Fitzgerald & Co. in May 2018.

In May 2018, we entered into an At Market Issuance Sales Agreement (the “Agreement”) with B. Riley FBR, Inc. (“BRFBR”) with respect to an at-the-market offering program under which we may offer and sell, from time to time at our sole discretion, up to 20 million shares of our common stock through BRFBR as our sales agent. The issuance and sale of the shares under the Agreement are made pursuant to our 2017 Registration Statement. In December 2018, we filed a prospectus supplement with the SEC in connection with the offer and sale of up to an additional 30 million shares from time to time pursuant to the Agreement. During the year ended December 31, 2019, no shares of our common stock were sold in at-the-market offerings under the Agreement.

On December 20, 2018, in connection of the Gilead Collaboration Agreement we also entered into the Stock Purchase Agreement (the “Gilead Stock Purchase Agreement”) with Gilead Sciences, Inc. (“Gilead”), pursuant to which Gilead purchased approximately 11.11 million shares of our common stock (the “Shares”) for an aggregate purchase price of $30.0 million, or $2.70 per Share. Gilead owned approximately 8.5% of the outstanding shares of our common stock after such purchase. Under the Stock Purchase Agreement, Gilead has agreed (i) not to dispose of any of the Shares for a period of 12 months, (ii) to certain standstill provisions that generally preclude it from acquiring more than 15% of our outstanding voting stock after taking into account the purchase of the Shares and (iii) to vote the Shares in accordance with the recommendations of our board of directors in connection with certain equity incentive plan or compensation matters for a period of 12 months. In the Gilead Stock Purchase Agreement, we agreed to register the Shares for resale under the Securities Act of 1933, and in October 2019 we filed a registration statement with the SEC accordingly.