RedHill Biopharma announced the U.S. Food and Drug Administration (FDA) has cleared the Company's Investigational New Drug (IND) application for a Phase 2/3 study evaluating orally administered RHB-107 (upamostat) in patients with symptomatic COVID-19 who do not require hospitalization.

"This is a significant milestone in our efforts to combat the effects of the COVID-19 pandemic. The ability to treat patients earlier in the course of COVID-19 disease, using an oral therapy that enables treatment outside of a hospital setting, is of critical importance given the large proportion of patients that are not hospitalized but are still very much at risk of disease progression," said Terry F. Plasse MD, Medical Director at RedHill. "With RHB-107 and opaganib, RedHill has two novel, late-stage, oral therapeutic candidates with potential to reduce the impact of COVID-19 disease, both of which target host cell components, potentially minimizing the likelihood of resistance due to emergence of viral mutations."

RHB-107 is a proprietary, first-in-class, orally administered potent inhibitor of several serine proteases, with demonstrated antiviral and potential tissue-protective effects. This combined antiviral and potential tissue-protective action make it a promising candidate for evaluation as a treatment for COVID-19 disease. RHB-107 has demonstrated strong inhibition of SARS-CoV-2 viral replication in an in vitro human bronchial cell model and its safety profile has been demonstrated in approximately 200 people, including in Phase 2 studies in oncology indications. RedHill licensed RHB-107 (formerly Mesupron) from Heidelberg Pharma AG (FWB: HPHA, formerly Wilex AG).

The randomized, parallel-group double-blind Phase 2/3 study is expected to start enrolling patients early next year. The study will enroll patients with symptomatic diagnostically confirmed COVID-19 who do not require inpatient care. RHB-107 will be administered once daily for 14 days, with patients receiving follow-up for eight weeks from first dosing. The primary endpoints will be time to recovery from symptomatic illness compared to placebo, as well as safety and tolerability of RHB-107. Several secondary and exploratory endpoints will also be assessed.

The late-stage development program for RedHill's other COVID-19 candidate, opaganib, in patients with severe COVID-19 pneumonia includes: The U.S. Phase 2 study (NCT04414618) is now fully enrolled and expected to report topline data in the coming weeks; and the global Phase 2/3 study (NCT04467840) which is more than 50% enrolled and is on track to enroll up to 270 patients and report topline data in support of potential emergency use applications in the first quarter of 2021. Both studies are randomized, double-blind, parallel-arm, placebo-controlled trials with opaganib in patients with severe COVID-19 pneumonia requiring hospitalization and treatment with supplemental oxygen.

RHB-107 is a proprietary, first-in-class, orally administered potent inhibitor of several serine proteases, with demonstrated antiviral and potential tissue-protective effects. This combined antiviral and potential tissue-protective action make it a strong candidate for evaluation as a treatment for COVID-19 disease. In addition, RHB-107 has potential in targeting cancer, inflammatory lung diseases and gastrointestinal diseases, and has undergone several Phase 1 studies and two Phase 2 studies, demonstrating its clinical safety profile in approximately 200 patients. RedHill acquired the exclusive worldwide rights to RHB-107, excluding China, Hong Kong, S.A.R., China, Taiwan, China and Macau, S.A.R., China, from Germany's Heidelberg Pharmaceuticals (formerly WILEX AG) for all indications.