Nature of the Business	6 Months Ended
Jun. 30, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Nature of the Business	1. Nature of the Business Eloxx Pharmaceuticals, Inc., together with its subsidiaries (collectively “Eloxx” or the “Company”), is a clinical-stage biopharmaceutical company developing novel ribonucleic acid (RNA)-modulating drug candidates, each designed to be a eukaryotic ribosomal selective glycoside (ERSG), formulated to treat rare and ultra-rare premature stop codon diseases. Premature stop codons are point mutations that disrupt the stability of the impacted messenger RNA (mRNA) and the protein synthesis from that mRNA. As a consequence, patients with premature stop codon diseases have reduced levels of, or no, protein from a gene whose product performs an essential function. This type of mutation accounts for some of the most severe phenotypes across genetic diseases. Nonsense mutations have been identified in over 1,800 rare and ultra-rare diseases. Read-through therapeutic development is focused on increasing functional protein synthesis by enabling the cytoplasmic ribosome to read through premature stop codons to produce full-length proteins. As opposed to a typical gene therapy approach of targeting a single, unique mutation in a target disease, this small molecule strategy enables targeting an entire class of mutations across the rare disease landscape. The small molecule approach has the potential to address a range of different premature stop codons in a single gene since the ERSG compounds are targeted to the ribosomes. ELX-02, the Company’s lead investigational drug product candidate, is a small molecule designed to restore production of full-length functional proteins. ELX-02 is in clinical development for systemic administration for cystic fibrosis. ELX-02 is an investigational drug that has not been approved by any global regulatory body. The Company is also conducting investigational new drug (IND) enabling preclinical studies of ERSG compounds for autosomal dominant polycystic kidney disease (ADPKD) and in rare inherited retinal disorders (IRDs) by intravitreal administration with an initial focus on Usher Syndrome. The Company’s preclinical candidate pool consists of a library of novel ERSG drug candidates identified based on read-through potential and cytoplasmic ribosomal selectivity. The Company is headquartered in Waltham, Massachusetts, with additional offices in Morristown, New Jersey and Rehovot, Israel. The Company’s research and development strategy is to target rare or ultra-rare diseases where a high unmet medical need exists, a nonsense mutation-bearing patient population is established, preclinical read-through can be established in predictive personalized medicine models, and a defined path through Orphan Drug development, regulatory approval, patient access and commercialization is identified. The Company believes patient advocacy is an important element of patient focused drug development and seeks opportunities to collaborate with patient advocacy groups throughout the discovery and development process. The Company’s current clinical program for its lead investigational drug product candidate, ELX-02, includes Phase 2 studies in cystic fibrosis in Europe, Israel and the United States. On March 25, 2020, the Company announced that enrollment in its Phase 2 clinical trials for ELX-02 in cystic fibrosis had been temporarily paused in response to the COVID-19 pandemic in order to avoid unnecessary exposure in at-risk populations, to maintain the integrity of study data and to support global healthcare providers in their commitment to ensure patient safety. On June 17, 2020, the Company announced that enrollment in its Phase 2 clinical trial in cystic fibrosis has been resumed in Israel and Europe, and that its U.S. trial remains temporarily paused due to the COVID-19 pandemic. The extent and severity of the impact of the current global health crisis on the Company’s business and clinical trials will be determined largely by the ability of patients and prospective patients in its clinical trials to access trial sites, the ability of personnel from clinical research organizations (“CROs”) to administer the Company’s drug in accordance with trial protocols and the Company’s ability to monitor and communicate effectively with CROs, staff at clinical trial sites and principal investigators. In addition, the impact of the COVID-19 pandemic on the operations of the U.S. Food and Drug Administration and other health authorities may delay potential advancement of the Company’s product candidates. The Company cannot reasonably estimate the extent to which these potential disruptions may materially impact its consolidated results of operations or financial position. During 2019, the Company announced that the Cystic Fibrosis Foundation (the “CF Foundation”) is providing funding for a portion of the U.S. Phase 2 cystic fibrosis clinical trial and that it will form a joint program advisory group with the CF Foundation focused on the development of ELX-02 for cystic fibrosis. The Cystic Fibrosis Therapeutics Development Network (“TDN”) has sanctioned the Phase 2 study protocol, which is being conducted at TDN member sites. On August 4, 2020, the Company announced that the U.S. Food and Drug Administration (FDA) has granted the Company orphan drug designation for ELX-02 for the treatment of cystic fibrosis. The FDA’s Office of Orphan Drug Products grants orphan status to support the development of medicines for underserved patient populations, or rare disorders, that affect fewer than 200,000 people in the U.S. Orphan drug designation qualifies Eloxx for certain benefits, including seven years of market exclusivity upon regulatory approval (if received), exemption from FDA application fees, tax credits on qualified U.S. clinical trials and eligibility for grant funding opportunities that can be used for clinical trial costs. ELX-02 had previously been granted orphan medicinal product designation for the treatment of cystic fibrosis by the European Medicines Agency. Liquidity The Company has a history of net losses and negative cash flows from operating activities since inception, and as of June 30, 2020, had an accumulated deficit of $(158.9) million. The Company expects to continue to incur net losses and use cash in its operations for the foreseeable future. To date, the Company has not generated revenue from the sale of any product or service and does not expect to generate significant revenue unless and until it obtains marketing approval for and commercializes one or more of its product candidates currently in development. Successful transition to profitable operations is dependent upon achieving a level of revenue adequate to support the Company’s cost structure. The Company has financed its operations primarily from the sale of equity securities and to a lesser extent, loans and grants. The Company may never achieve profitability, and unless and until it does, the Company will continue to need to raise additional capital to fund its operations. As discussed in Note 14, on February 24, 2020, the Company’s Board of Directors approved a leadership and organizational realignment, aimed at supporting the Company’s efforts to improve operating performance, and concentrate development efforts on the Company’s core programs. The Company believes that its cash, cash equivalents and marketable securities of $37.1 million at June 30, 2020 will enable it to meet anticipated cash needs required to maintain the Company’s current and planned operations through at least the next 12 months from the issuance of the financial statements for the quarter ended June 30, 2020. Management intends to fund future operations through private or public debt or equity financing transactions and may seek additional capital through arrangements with strategic partners or from other sources. If the Company is unable to obtain adequate financing, it will evaluate options which may include reducing or deferring operating expenses, which may have a material adverse effect on the Company’s operations and future prospects.

Nature of the Business

6 Months Ended

Jun. 30, 2020

Organization Consolidation And Presentation Of Financial Statements [Abstract]

1. Nature of the Business

Eloxx Pharmaceuticals, Inc., together with its subsidiaries (collectively “Eloxx” or the “Company”), is a clinical-stage biopharmaceutical company developing novel ribonucleic acid (RNA)-modulating drug candidates, each designed to be a eukaryotic ribosomal selective glycoside (ERSG), formulated to treat rare and ultra-rare premature stop codon diseases. Premature stop codons are point mutations that disrupt the stability of the impacted messenger RNA (mRNA) and the protein synthesis from that mRNA. As a consequence, patients with premature stop codon diseases have reduced levels of, or no, protein from a gene whose product performs an essential function. This type of mutation accounts for some of the most severe phenotypes across genetic diseases. Nonsense mutations have been identified in over 1,800 rare and ultra-rare diseases. Read-through therapeutic development is focused on increasing functional protein synthesis by enabling the cytoplasmic ribosome to read through premature stop codons to produce full-length proteins. As opposed to a typical gene therapy approach of targeting a single, unique mutation in a target disease, this small molecule strategy enables targeting an entire class of mutations across the rare disease landscape. The small molecule approach has the potential to address a range of different premature stop codons in a single gene since the ERSG compounds are targeted to the ribosomes. ELX-02, the Company’s lead investigational drug product candidate, is a small molecule designed to restore production of full-length functional proteins. ELX-02 is in clinical development for systemic administration for cystic fibrosis. ELX-02 is an investigational drug that has not been approved by any global regulatory body. The Company is also conducting investigational new drug (IND) enabling preclinical studies of ERSG compounds for autosomal dominant polycystic kidney disease (ADPKD) and in rare inherited retinal disorders (IRDs) by intravitreal administration with an initial focus on Usher Syndrome.

The Company’s preclinical candidate pool consists of a library of novel ERSG drug candidates identified based on read-through potential and cytoplasmic ribosomal selectivity. The Company is headquartered in Waltham, Massachusetts, with additional offices in Morristown, New Jersey and Rehovot, Israel.

The Company’s research and development strategy is to target rare or ultra-rare diseases where a high unmet medical need exists, a nonsense mutation-bearing patient population is established, preclinical read-through can be established in predictive personalized medicine models, and a defined path through Orphan Drug development, regulatory approval, patient access and commercialization is identified. The Company believes patient advocacy is an important element of patient focused drug development and seeks opportunities to collaborate with patient advocacy groups throughout the discovery and development process. The Company’s current clinical program for its lead investigational drug product candidate, ELX-02, includes Phase 2 studies in cystic fibrosis in Europe, Israel and the United States. On March 25, 2020, the Company announced that enrollment in its Phase 2 clinical trials for ELX-02 in cystic fibrosis had been temporarily paused in response to the COVID-19 pandemic in order to avoid unnecessary exposure in at-risk populations, to maintain the integrity of study data and to support global healthcare providers in their commitment to ensure patient safety. On June 17, 2020, the Company announced that enrollment in its Phase 2 clinical trial in cystic fibrosis has been resumed in Israel and Europe, and that its U.S. trial remains temporarily paused due to the COVID-19 pandemic.

The extent and severity of the impact of the current global health crisis on the Company’s business and clinical trials will be determined largely by the ability of patients and prospective patients in its clinical trials to access trial sites, the ability of personnel from clinical research organizations (“CROs”) to administer the Company’s drug in accordance with trial protocols and the Company’s ability to monitor and communicate effectively with CROs, staff at clinical trial sites and principal investigators. In addition, the impact of the COVID-19 pandemic on the operations of the U.S. Food and Drug Administration and other health authorities may delay potential advancement of the Company’s product candidates. The Company cannot reasonably estimate the extent to which these potential disruptions may materially impact its consolidated results of operations or financial position.

During 2019, the Company announced that the Cystic Fibrosis Foundation (the “CF Foundation”) is providing funding for a portion of the U.S. Phase 2 cystic fibrosis clinical trial and that it will form a joint program advisory group with the CF Foundation focused on the development of ELX-02 for cystic fibrosis. The Cystic Fibrosis Therapeutics Development Network (“TDN”) has sanctioned the Phase 2 study protocol, which is being conducted at TDN member sites. On August 4, 2020, the Company announced that the U.S. Food and Drug Administration (FDA) has granted the Company orphan drug designation for ELX-02 for the treatment of cystic fibrosis. The FDA’s Office of Orphan Drug Products grants orphan status to support the development of medicines for underserved patient populations, or rare disorders, that affect fewer than 200,000 people in the U.S. Orphan drug designation qualifies Eloxx for certain benefits, including seven years of market exclusivity upon regulatory approval (if received), exemption from FDA application fees, tax credits on qualified U.S. clinical trials and eligibility for grant funding opportunities that can be used for clinical trial costs. ELX-02 had previously been granted orphan medicinal product designation for the treatment of cystic fibrosis by the European Medicines Agency.

Liquidity

The Company has a history of net losses and negative cash flows from operating activities since inception, and as of June 30, 2020, had an accumulated deficit of $(158.9) million. The Company expects to continue to incur net losses and use cash in its operations for the foreseeable future. To date, the Company has not generated revenue from the sale of any product or service and does not expect to generate significant revenue unless and until it obtains marketing approval for and commercializes one or more of its product candidates currently in development. Successful transition to profitable operations is dependent upon achieving a level of revenue adequate to support the Company’s cost structure.

The Company has financed its operations primarily from the sale of equity securities and to a lesser extent, loans and grants. The Company may never achieve profitability, and unless and until it does, the Company will continue to need to raise additional capital to fund its operations. As discussed in Note 14, on February 24, 2020, the Company’s Board of Directors approved a leadership and organizational realignment, aimed at supporting the Company’s efforts to improve operating performance, and concentrate development efforts on the Company’s core programs. The Company believes that its cash, cash equivalents and marketable securities of $37.1 million at June 30, 2020 will enable it to meet anticipated cash needs required to maintain the Company’s current and planned operations through at least the next 12 months from the issuance of the financial statements for the quarter ended June 30, 2020. Management intends to fund future operations through private or public debt or equity financing transactions and may seek additional capital through arrangements with strategic partners or from other sources. If the Company is unable to obtain adequate financing, it will evaluate options which may include reducing or deferring operating expenses, which may have a material adverse effect on the Company’s operations and future prospects.