Organization and Operations	12 Months Ended
Dec. 31, 2017
Organization and Operations
Organization and Operations	1. Organization and Operations The Company Catabasis Pharmaceuticals, Inc. (the "Company") is a clinical-stage biopharmaceutical company focused on the discovery, development and commercialization of novel therapeutics based on the Company's proprietary Safely Metabolized And Rationally Targeted, or SMART, linker, or SMART LinkerSM, drug discovery platform. The Company's SMART Linker technology platform enables the Company to engineer product candidates that can simultaneously modulate multiple targets in a disease. The Company's proprietary product candidates impact pathways that are central to diseases where efficacy may be optimized by a multiple target approach. The Company's primary focus is on treatments for rare diseases. The Company has applied its SMART Linker drug discovery platform to build an internal pipeline of product candidates for rare diseases and plans to pursue partnerships to develop additional product candidates. The Company was incorporated in the State of Delaware on June 26, 2008. Liquidity and Going Concern In August 2016, the Company entered into a sales agreement with Cowen and Company LLC, ("Cowen"), pursuant to which the Company could issue and sell shares of common stock for an aggregate maximum offering amount of $10.0 million under an at-the-market offering program (the "First ATM Program"). In March 2017, the Company reduced the maximum amount of the offering under the First ATM Program to $8.8 million, which was fully utilized as of September 30, 2017. In October 2017, the Company entered into a second sales agreement with Cowen pursuant to which the Company may issue and sell shares of common stock for an aggregate maximum offering amount of $10.0 million under a second at-the-market offering program (the "Second ATM Program"). Cowen is not required to sell any specific amount, but acts as the Company's sales agent using commercially reasonable efforts consistent with its normal trading and sales practices. Shares sold pursuant to the sales agreement have been sold pursuant to a shelf registration statement, which became effective on July 19, 2016. The Company pays Cowen 3% of the gross proceeds from any common stock sold through these sales agreements. During the year ended December 31, 2017, the Company sold an aggregate of 4,804,796 shares of common stock pursuant to the First ATM Program, at an average price of $1.79 per share, for gross proceeds of $8.6 million, resulting in net proceeds of $8.0 million after deducting sales commissions and offering. As of December 31, 2017, $8.6 million of common stock remained available for sale under the Second ATM Program. Subsequent to December 31, 2017, the Company sold an aggregate of 5,390,255 shares of common stock pursuant to the Second ATM Program, at an average price of $1.59 per share, for gross proceeds of $8.6 million, representing the remainder of the common stock that could be sold under the Second ATM Program, resulting in net proceeds of $8.3 million after deducting sales commissions and offering expenses, thus the Second ATM Program has been fully utilized. During the year ended December 31, 2016, the Company sold an aggregate of 3,243,015 shares of common stock either through a direct offering or an at-the-market offering at an average offering price of $4.04 per share. The shares sold in the offering were sold pursuant to the Shelf Registration Statement. The Company received aggregate gross proceeds from the sales of $13.1 million, resulting in net proceeds of $12.0 million after deducting underwriting discounts and commissions and offering expenses. As of December 31, 2017, the Company had an accumulated deficit of $171.4 million. The Company has been primarily involved with research and development activities and has incurred operating losses and negative cash flows from operations since its inception. The Company is subject to a number of risks including, but not limited to, the need to obtain adequate additional funding, including the resources necessary to fund a global Phase 3 clinical trial of edasalonexent in DMD, which the Company plans to begin in the first half of 2018. The Company is currently exploring various avenues to secure capital to advance edasalonexent into a Phase 3 clinical trial, and its Phase 3 development activities will be dependent on securing adequate capital resources. The Company is also subject to a number of risks similar to other life science companies, including, but not limited to, successful discovery and development of its drug candidates, raising additional capital, development by its competitors of new technological innovations, protection of proprietary technology and regulatory approval and market acceptance of the Company's products. The Company anticipates that it will continue to incur significant operating losses for the next several years as it continues to develop its product candidates. As of December 31, 2017, the Company had available cash and cash equivalents of $16.4 million. The Company's current operating plan provides for cash to fund operations through September 2018. Based on the Company's available cash resources, the Company does not have sufficient cash on hand to support current operations for at least the next twelve months from the date of filing this Annual Report on Form 10-K. This condition requires substantial doubt about the Company's ability to continue as a going concern. The Company's plans to address this condition include seeking additional funds through equity or debt financings or through collaboration or licensing transactions. The Company may be unable to obtain equity or debt financings or enter into collaboration or licensing transactions and, if necessary, the Company will be required to implement cost reduction strategies, including ceasing or delaying development of the Company's product candidates. Accordingly, the Company has concluded that substantial doubt exists regarding the Company's ability to continue as a going concern for a period of at least twelve months from the date of issuance of these consolidated financial statements. The accompanying 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 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. The Company will require substantial additional capital to fund operations. The Company has not generated any product revenues and has financed its operations primarily through public offerings and private placements of its equity securities. There can be no assurance that the Company will be able to obtain additional debt or equity financing or generate product revenue or revenues from collaborative partners, on terms acceptable to the Company, on a timely basis or at all. The failure of the Company to obtain sufficient funds on acceptable terms when needed could have a material adverse effect on the Company's business, results of operations, and financial condition.

1. Organization and Operations

The Company

Catabasis Pharmaceuticals, Inc. (the "Company") is a clinical-stage biopharmaceutical company focused on the discovery, development and commercialization of novel therapeutics based on the Company's proprietary Safely Metabolized And Rationally Targeted, or SMART, linker, or SMART LinkerSM, drug discovery platform. The Company's SMART Linker technology platform enables the Company to engineer product candidates that can simultaneously modulate multiple targets in a disease. The Company's proprietary product candidates impact pathways that are central to diseases where efficacy may be optimized by a multiple target approach. The Company's primary focus is on treatments for rare diseases. The Company has applied its SMART Linker drug discovery platform to build an internal pipeline of product candidates for rare diseases and plans to pursue partnerships to develop additional product candidates. The Company was incorporated in the State of Delaware on June 26, 2008.

Liquidity and Going Concern

In August 2016, the Company entered into a sales agreement with Cowen and Company LLC, ("Cowen"), pursuant to which the Company could issue and sell shares of common stock for an aggregate maximum offering amount of $10.0 million under an at-the-market offering program (the "First ATM Program"). In March 2017, the Company reduced the maximum amount of the offering under the First ATM Program to $8.8 million, which was fully utilized as of September 30, 2017. In October 2017, the Company entered into a second sales agreement with Cowen pursuant to which the Company may issue and sell shares of common stock for an aggregate maximum offering amount of $10.0 million under a second at-the-market offering program (the "Second ATM Program"). Cowen is not required to sell any specific amount, but acts as the Company's sales agent using commercially reasonable efforts consistent with its normal trading and sales practices. Shares sold pursuant to the sales agreement have been sold pursuant to a shelf registration statement, which became effective on July 19, 2016. The Company pays Cowen 3% of the gross proceeds from any common stock sold through these sales agreements.

During the year ended December 31, 2017, the Company sold an aggregate of 4,804,796 shares of common stock pursuant to the First ATM Program, at an average price of $1.79 per share, for gross proceeds of $8.6 million, resulting in net proceeds of $8.0 million after deducting sales commissions and offering. As of December 31, 2017, $8.6 million of common stock remained available for sale under the Second ATM Program. Subsequent to December 31, 2017, the Company sold an aggregate of 5,390,255 shares of common stock pursuant to the Second ATM Program, at an average price of $1.59 per share, for gross proceeds of $8.6 million, representing the remainder of the common stock that could be sold under the Second ATM Program, resulting in net proceeds of $8.3 million after deducting sales commissions and offering expenses, thus the Second ATM Program has been fully utilized.

During the year ended December 31, 2016, the Company sold an aggregate of 3,243,015 shares of common stock either through a direct offering or an at-the-market offering at an average offering price of $4.04 per share. The shares sold in the offering were sold pursuant to the Shelf Registration Statement. The Company received aggregate gross proceeds from the sales of $13.1 million, resulting in net proceeds of $12.0 million after deducting underwriting discounts and commissions and offering expenses.

As of December 31, 2017, the Company had an accumulated deficit of $171.4 million. The Company has been primarily involved with research and development activities and has incurred operating losses and negative cash flows from operations since its inception.

The Company is subject to a number of risks including, but not limited to, the need to obtain adequate additional funding, including the resources necessary to fund a global Phase 3 clinical trial of edasalonexent in DMD, which the Company plans to begin in the first half of 2018. The Company is currently exploring various avenues to secure capital to advance edasalonexent into a Phase 3 clinical trial, and its Phase 3 development activities will be dependent on securing adequate capital resources.

The Company is also subject to a number of risks similar to other life science companies, including, but not limited to, successful discovery and development of its drug candidates, raising additional capital, development by its competitors of new technological innovations, protection of proprietary technology and regulatory approval and market acceptance of the Company's products. The Company anticipates that it will continue to incur significant operating losses for the next several years as it continues to develop its product candidates.

As of December 31, 2017, the Company had available cash and cash equivalents of $16.4 million. The Company's current operating plan provides for cash to fund operations through September 2018. Based on the Company's available cash resources, the Company does not have sufficient cash on hand to support current operations for at least the next twelve months from the date of filing this Annual Report on Form 10-K. This condition requires substantial doubt about the Company's ability to continue as a going concern.

The Company's plans to address this condition include seeking additional funds through equity or debt financings or through collaboration or licensing transactions. The Company may be unable to obtain equity or debt financings or enter into collaboration or licensing transactions and, if necessary, the Company will be required to implement cost reduction strategies, including ceasing or delaying development of the Company's product candidates. Accordingly, the Company has concluded that substantial doubt exists regarding the Company's ability to continue as a going concern for a period of at least twelve months from the date of issuance of these consolidated financial statements. The accompanying 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 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.

The Company will require substantial additional capital to fund operations. The Company has not generated any product revenues and has financed its operations primarily through public offerings and private placements of its equity securities. There can be no assurance that the Company will be able to obtain additional debt or equity financing or generate product revenue or revenues from collaborative partners, on terms acceptable to the Company, on a timely basis or at all. The failure of the Company to obtain sufficient funds on acceptable terms when needed could have a material adverse effect on the Company's business, results of operations, and financial condition.