Nature of Business	6 Months Ended
Jun. 30, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Nature of Business	1. Nature of Business Allena Pharmaceuticals, Inc. (the “Company”) is a late-stage clinical biopharmaceutical company dedicated to developing and commercializing first-in-class, oral enzyme therapeutics to treat patients with rare and severe metabolic and kidney disorders. The Company is focused on metabolic disorders that result in excess accumulation of certain metabolites that can cause kidney stones, damage the kidney, and potentially lead to chronic kidney disease (“CKD”) and end-stage renal disease. The Company’s lead product candidate, reloxaliase (formerly known as ALLN-177), is a first-in-class, oral enzyme therapeutic that it is developing for the treatment of hyperoxaluria, a metabolic disorder commonly associated with kidney stones, CKD and other serious kidney diseases. The Company was incorporated under the laws of the State of Delaware on June 24, 2011 and is located in Newton, Massachusetts. On June 5, 2020, the Company completed a registered direct offering, in which the Company issued and sold 7,317,074 shares of its common stock, at a purchase price of $2.05 per share, for gross proceeds of $15.0 million through a securities purchase agreement with certain institutional and accredited investors. The shares of common stock sold in this offering were being offered by the Company pursuant to an effective shelf registration statement on Form S-3, which was originally filed with the Securities and Exchange Commission (the “SEC”) on December 3, 2018, as amended, and was declared effective on December 26, 2018 (File No. 333-228656) and a prospectus supplement thereunder filed on June 5, 2020. As a result of the registered direct offering, the Company received approximately $13.7 million after deducting offering costs. On July 30, 2020, the Company completed a public underwritten offering of 5,894,191 shares of its common stock, including the exercise in full of the underwriter’s option to purchase an additional 768,807 shares of common stock, at a price to the public of $1.30 per share, for gross proceeds of $7.7 million , before deducting underwriting discounts and commissions and offering expenses. As a result of this public offering, the Company received approximately $6.7 million after deducting offering costs. The Company is subject to risks common to companies in the biotechnology industry, including but not limited to, risks of failure of preclinical studies and clinical trials, the need to obtain marketing approval for any drug product candidate that it may identify and develop, the need to successfully commercialize and gain market acceptance of its product candidates, dependence on key personnel, protection of proprietary technology, compliance with government regulations, development by competitors of technological innovations, reliance on third party manufacturers, ability to transition from pilot-scale manufacturing to large-scale production of products and the need to obtain adequate additional financing to fund the development of its product candidates. Liquidity and Going Concern The Company had an accumulated deficit of $179.5 million at June 30, 2020 and will require substantial additional capital to fund operations. The future success of the Company is dependent on its ability to identify and develop its product candidates and ultimately upon its ability to attain profitable operations. At June 30, 2020, the Company had $26.5 million of cash and cash equivalents. The Company’s available cash and cash equivalents as of June 30, 2020 are not sufficient to fund the Company’s current operating plan for at least the next twelve months following the filing of this Quarterly Report on Form 10-Q. The Company requires additional capital to sustain its operations, including its reloxaliase development program. Management is working to seek additional funds through equity or debt financings or through collaborations, licensing transactions or other sources. The Company may be unable to obtain equity or debt financings or enter into collaboration or licensing transactions. Market volatility resulting from the COVID-19 pandemic or other factors could also adversely impact the Company’s ability to access capital as and when needed. The failure to obtain sufficient funds when needed would have a material adverse effect on the Company’s business, results of operations and financial condition and jeopardize its ability to continue operations. The Company may implement cost reduction strategies, which may include amending, delaying, limiting, reducing, or terminating one or more of its ongoing or planned clinical trials or development programs of its product candidates. These factors raise substantial doubt about the Company’s ability to continue as a going concern. The accompanying condensed consolidated financial statements have been prepared on a going concern basis, which contemplates the realization of assets and satisfaction of liabilities in the ordinary course of business. The condensed consolidated financial statements do not include any adjustments relating to the recoverability and classification of recorded asset amounts or the amounts and classification of liabilities that might result from the outcome of this uncertainty.

Nature of Business

6 Months Ended

Jun. 30, 2020

Organization Consolidation And Presentation Of Financial Statements [Abstract]

1. Nature of Business

Allena Pharmaceuticals, Inc. (the “Company”) is a late-stage clinical biopharmaceutical company dedicated to developing and commercializing first-in-class, oral enzyme therapeutics to treat patients with rare and severe metabolic and kidney disorders. The Company is focused on metabolic disorders that result in excess accumulation of certain metabolites that can cause kidney stones, damage the kidney, and potentially lead to chronic kidney disease (“CKD”) and end-stage renal disease. The Company’s lead product candidate, reloxaliase (formerly known as ALLN-177), is a first-in-class, oral enzyme therapeutic that it is developing for the treatment of hyperoxaluria, a metabolic disorder commonly associated with kidney stones, CKD and other serious kidney diseases. The Company was incorporated under the laws of the State of Delaware on June 24, 2011 and is located in Newton, Massachusetts.

On June 5, 2020, the Company completed a registered direct offering, in which the Company issued and sold 7,317,074 shares of its common stock, at a purchase price of $2.05 per share, for gross proceeds of $15.0 million through a securities purchase agreement with certain institutional and accredited investors. The shares of common stock sold in this offering were being offered by the Company pursuant to an effective shelf registration statement on Form S-3, which was originally filed with the Securities and Exchange Commission (the “SEC”) on December 3, 2018, as amended, and was declared effective on December 26, 2018 (File No. 333-228656) and a prospectus supplement thereunder filed on June 5, 2020. As a result of the registered direct offering, the Company received approximately $13.7 million after deducting offering costs.

On July 30, 2020, the Company completed a public underwritten offering of 5,894,191 shares of its common stock, including the exercise in full of the underwriter’s option to purchase an additional 768,807 shares of common stock, at a price to the public of $1.30 per share, for gross proceeds of $7.7 million , before deducting underwriting discounts and commissions and offering expenses. As a result of this public offering, the Company received approximately $6.7 million after deducting offering costs.

The Company is subject to risks common to companies in the biotechnology industry, including but not limited to, risks of failure of preclinical studies and clinical trials, the need to obtain marketing approval for any drug product candidate that it may identify and develop, the need to successfully commercialize and gain market acceptance of its product candidates, dependence on key personnel, protection of proprietary technology, compliance with government regulations, development by competitors of technological innovations, reliance on third party manufacturers, ability to transition from pilot-scale manufacturing to large-scale production of products and the need to obtain adequate additional financing to fund the development of its product candidates.

Liquidity and Going Concern

The Company had an accumulated deficit of $179.5 million at June 30, 2020 and will require substantial additional capital to fund operations. The future success of the Company is dependent on its ability to identify and develop its product candidates and ultimately upon its ability to attain profitable operations. At June 30, 2020, the Company had $26.5 million of cash and cash equivalents. The Company’s available cash and cash equivalents as of June 30, 2020 are not sufficient to fund the Company’s current operating plan for at least the next twelve months following the filing of this Quarterly Report on Form 10-Q. The Company requires additional capital to sustain its operations, including its reloxaliase development program. Management is working to seek additional funds through equity or debt financings or through collaborations, licensing transactions or other sources. The Company may be unable to obtain equity or debt financings or enter into collaboration or licensing transactions. Market volatility resulting from the COVID-19 pandemic or other factors could also adversely impact the Company’s ability to access capital as and when needed. The failure to obtain sufficient funds when needed would have a material adverse effect on the Company’s business, results of operations and financial condition and jeopardize its ability to continue operations. The Company may implement cost reduction strategies, which may include amending, delaying, limiting, reducing, or terminating one or more of its ongoing or planned clinical trials or development programs of its product candidates. These factors raise substantial doubt about the Company’s ability to continue as a going concern. The accompanying condensed consolidated financial statements have been prepared on a going concern basis, which contemplates the realization of assets and satisfaction of liabilities in the ordinary course of business. The condensed consolidated financial statements do not include any adjustments relating to the recoverability and classification of recorded asset amounts or the amounts and classification of liabilities that might result from the outcome of this uncertainty.