Liquidity	3 Months Ended
Mar. 31, 2020
Liquidity [Abstract]
Liquidity	2. Liquidity The Company has prepared its consolidated financial statements on a going concern basis, which assumes that the Company will realize its assets and satisfy its liabilities in the normal course of business. However, the Company has incurred net losses since its inception and has negative operating cash flows. These circumstances raise substantial doubt about the Company’s ability to continue as a going concern. The accompanying financial statements do not include any adjustments to reflect the possible future effects on the recoverability and classification of assets or the amounts and classifications of liabilities that may result from the outcome of the uncertainty concerning the Company’s ability to continue as a going concern. As described in more detail in Note 8, on March 27, 2020, the Company completed a private placement transaction and sold to Innoviva Inc. (“Innoviva”) 8,710,800 newly issued shares of the Company’s common stock and warrants to purchase 8,710,800 shares of common stock, with an exercise price per share of $2.87 (the “Private Placement”). Each share of common stock was sold together with one common warrant granting the warrant holder the right to purchase an additional share of common stock at $2.87 per share. The Private Placement was closed in two tranches raising total gross proceeds of $25.0 million. As of March 31, 2020, the Company had cash and cash equivalents of $24.2 million. Considering the Company’s current cash resources, management believes the Company’s existing resources will be sufficient to fund the Company’s planned operations into the second quarter of 2021. For the foreseeable future, the Company’s ability to continue its operations is dependent upon its ability to obtain additional capital. Management plans to raise additional capital through equity offerings, debt financings, or other capital sources, including potential collaborations, grants, licensing of intellectual property, and other similar arrangements. While management believes this plan to raise additional funds will alleviate the conditions that raise substantial doubt, these plans are not entirely within its control and cannot be assessed as being probable of occurring. The Company’s ability to raise additional capital may be adversely impacted by potential worsening global economic conditions and the recent disruptions to, and volatility in, financial markets in the United States and worldwide resulting from the ongoing COVID-19 pandemic. The Company may not be able to secure additional financing in a timely manner or on favorable terms, if at all. Furthermore, if the Company issues equity securities to raise additional funds, its existing stockholders may experience dilution, and the new equity securities may have rights, preferences and privileges senior to those of the Company’s existing stockholders. If the Company raises additional funds through collaboration, licensing or other similar arrangements, it may be necessary to relinquish valuable rights to its potential products on terms that are not favorable to the Company. If the Company is unable to raise capital when needed or on attractive terms, it would be forced to delay, reduce or eliminate its research and development programs or other operations. If any of these events occur, the Company’s ability to achieve the development and commercialization goals would be adversely affected.

2. Liquidity

The Company has prepared its consolidated financial statements on a going concern basis, which assumes that the Company will realize its assets and satisfy its liabilities in the normal course of business. However, the Company has incurred net losses since its inception and has negative operating cash flows. These circumstances raise substantial doubt about the Company’s ability to continue as a going concern. The accompanying financial statements do not include any adjustments to reflect the possible future effects on the recoverability and classification of assets or the amounts and classifications of liabilities that may result from the outcome of the uncertainty concerning the Company’s ability to continue as a going concern.

As described in more detail in Note 8, on March 27, 2020, the Company completed a private placement transaction and sold to Innoviva Inc. (“Innoviva”) 8,710,800 newly issued shares of the Company’s common stock and warrants to purchase 8,710,800 shares of common stock, with an exercise price per share of $2.87 (the “Private Placement”). Each share of common stock was sold together with one common warrant granting the warrant holder the right to purchase an additional share of common stock at $2.87 per share. The Private Placement was closed in two tranches raising total gross proceeds of $25.0 million.

As of March 31, 2020, the Company had cash and cash equivalents of $24.2 million. Considering the Company’s current cash resources, management believes the Company’s existing resources will be sufficient to fund the Company’s planned operations into the second quarter of 2021. For the foreseeable future, the Company’s ability to continue its operations is dependent upon its ability to obtain additional capital.

Management plans to raise additional capital through equity offerings, debt financings, or other capital sources, including potential collaborations, grants, licensing of intellectual property, and other similar arrangements. While management believes this plan to raise additional funds will alleviate the conditions that raise substantial doubt, these plans are not entirely within its control and cannot be assessed as being probable of occurring. The Company’s ability to raise additional capital may be adversely impacted by potential worsening global economic conditions and the recent disruptions to, and volatility in, financial markets in the United States and worldwide resulting from the ongoing COVID-19 pandemic. The Company may not be able to secure additional financing in a timely manner or on favorable terms, if at all. Furthermore, if the Company issues equity securities to raise additional funds, its existing stockholders may experience dilution, and the new equity securities may have rights, preferences and privileges senior to those of the Company’s existing stockholders. If the Company raises additional funds through collaboration, licensing or other similar arrangements, it may be necessary to relinquish valuable rights to its potential products on terms that are not favorable to the Company. If the Company is unable to raise capital when needed or on attractive terms, it would be forced to delay, reduce or eliminate its research and development programs or other operations. If any of these events occur, the Company’s ability to achieve the development and commercialization goals would be adversely affected.