Liquidity (Policies)	12 Months Ended
Dec. 31, 2021
Liquidity
Liquidity Policy	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. On February 9, 2022, the Company entered into a securities purchase agreement (“February 2022 Securities Purchase Agreement”) to sell its common stock and warrants to Innoviva Strategic Opportunities LLC, a wholly‐owned subsidiary of Innoviva, Inc. (Nasdaq: INVA) (collectively, "Innoviva"). The gross proceeds to the Company from the transaction are expected to be $45 million. Pursuant and subject to the terms and conditions of the securities purchase agreement and related agreements, Innoviva will purchase 9,000,000 newly issued shares of the Company’s common stock, at a price of $5.00 per share, and warrants to purchase up to 4,500,000 additional shares of common stock, with an exercise price of $5.00 per share. The stock purchases are expected to occur in two tranches. Upon execution , Innoviva purchased 3,614,792 shares of common stock and warrants to purchase 1,807,396 shares of common stock for an aggregate purchase price of approximately $18.1 million. At the closing of the second tranche, upon the Company’s stockholders voting in favor of the transaction, Innoviva will purchase 5,385,208 shares of common stock and warrants to purchase 2,692,604 shares of common stock for an aggregate purchase price of $26.9 million. Subject to the satisfaction of certain closing conditions, including the approval of the Company’s stockholders, the second closing contemplated by the securities purchase agreement is expected to occur near the end of the first quarter of 2022. On October 28, 2021, the Company entered into a securities purchase agreement (the “October 2021 Securities Purchase Agreement”) with the Cystic Fibrosis Foundation (“CFF”), a Delaware corporation, the Company’s partner for its lead Phase 1b/2a clinical development program, and Innoviva Strategic Opportunities LLC, a wholly-owned subsidiary of Innoviva, Inc. (Nasdaq: INVA) (collectively, “Innoviva”) for the private placement of newly issued shares of common stock, par value $0.01 per share, of the Company (“Common Stock”). Pursuant to the October 2021 Securities Purchase Agreement, the Company issued and sold 909,091 shares to CFF and 1,212,122 shares to Innoviva, each at a per share price of $3.30 (the “October 2021 Private Placements”). The Company received aggregate gross proceeds from the October 2021 Private Placements of approximately $7.0 million, before deducting transaction expenses. On January 26, 2021, the Company entered into a securities purchase agreement (the “January 2021 Securities Purchase Agreement”) with Innoviva, pursuant to which the Company issued and sold to Innoviva, in a private placement, up to 6,153,847 newly issued shares of Common Stock, and warrants (the “Common Warrants”) to purchase up to 6,153,847 shares of Common Stock, with an exercise price per share of $3.25 (the “January 2021 Private Placement”). On March 27, 2020, the Company completed a private placement transaction and sold to Innoviva Inc. 8,710,800 newly issued shares of Common Stock and warrants to purchase 8,710,800 shares of common stock, with an exercise price per share of $2.87 (the “2020 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 2020 Private Placement was closed in two tranches raising total gross proceeds of $25.0 million. Management plans to raise additional capital through equity offerings, debt financings, or other capital sources, including potential collaborations, licenses 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.

Liquidity (Policies)

12 Months Ended

Dec. 31, 2021

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.

On February 9, 2022, the Company entered into a securities purchase agreement (“February 2022 Securities Purchase Agreement”) to sell its common stock and warrants to Innoviva Strategic Opportunities LLC, a wholly‐owned subsidiary of Innoviva, Inc. (Nasdaq: INVA) (collectively, "Innoviva"). The gross proceeds to the Company from the transaction are expected to be $45 million.

Pursuant and subject to the terms and conditions of the securities purchase agreement and related agreements, Innoviva will purchase 9,000,000 newly issued shares of the Company’s common stock, at a price of $5.00 per share, and warrants to purchase up to 4,500,000 additional shares of common stock, with an exercise price of $5.00 per share. The stock purchases are expected to occur in two tranches. Upon execution , Innoviva purchased 3,614,792 shares of common stock and warrants to purchase 1,807,396 shares of common stock for an aggregate purchase price of approximately $18.1 million. At the closing of the second tranche, upon the Company’s stockholders voting in favor of the transaction, Innoviva will purchase 5,385,208 shares of common stock and warrants to purchase 2,692,604 shares of common stock for an aggregate purchase price of $26.9 million. Subject to the satisfaction of certain closing conditions, including the approval of the Company’s stockholders, the second closing contemplated by the securities purchase agreement is expected to occur near the end of the first quarter of 2022.

On October 28, 2021, the Company entered into a securities purchase agreement (the “October 2021 Securities Purchase Agreement”) with the Cystic Fibrosis Foundation (“CFF”), a Delaware corporation, the Company’s partner for its lead Phase 1b/2a clinical development program, and Innoviva Strategic Opportunities LLC, a wholly-owned subsidiary of Innoviva, Inc. (Nasdaq: INVA) (collectively, “Innoviva”) for the private placement of newly issued shares of common stock, par value $0.01 per share, of the Company (“Common Stock”). Pursuant to the October 2021 Securities Purchase Agreement, the Company issued and sold 909,091 shares to CFF and 1,212,122 shares to Innoviva, each at a per share price of $3.30 (the “October 2021 Private Placements”). The Company received aggregate gross proceeds from the October 2021 Private Placements of approximately $7.0 million, before deducting transaction expenses.

On January 26, 2021, the Company entered into a securities purchase agreement (the “January 2021 Securities Purchase Agreement”) with Innoviva, pursuant to which the Company issued and sold to Innoviva, in a private placement, up to 6,153,847 newly issued shares of Common Stock, and warrants (the “Common Warrants”) to purchase up to 6,153,847 shares of Common Stock, with an exercise price per share of $3.25 (the “January 2021 Private Placement”).

On March 27, 2020, the Company completed a private placement transaction and sold to Innoviva Inc. 8,710,800 newly issued shares of Common Stock and warrants to purchase 8,710,800 shares of common stock, with an exercise price per share of $2.87 (the “2020 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 2020 Private Placement was closed in two tranches raising total gross proceeds of $25.0 million.

Management plans to raise additional capital through equity offerings, debt financings, or other capital sources, including potential collaborations, licenses 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.