RedHill Biopharma Ltd., a specialty biopharmaceutical company, announced receipt of two Notices of Allowance from the U.S. Patent and Trademark Office (USPTO) covering opaganib[1] and RHB-107 (upamostat)[2] as methods for the treatment of COVID-19 caused by the SARS-CoV-2 virus.

Both opaganib and RHB-107 are novel COVID-19 therapeutic candidates, in oral pill form, with dual mechanism of action effects. Both are host-targeted and are therefore expected to be effective against emerging viral variants with various mutations in the spike protein.

"There is an urgent need for oral COVID-19 treatments for patients inside and outside of the hospital setting," said Danielle T. Abramson, Ph.D., VP, Intellectual Property & Research at RedHill. "With two novel oral COVID-19 therapeutics in late clinical-stage development, RedHill stands at the forefront of research for COVID-19 treatments. We are very pleased with the new intellectual property protection which extends until at least 2041. The Company has also filed for protection under the Patent Cooperation Treaty (PCT) and has the option of applying in the member countries thereof."

Enrollment in opaganib's global Phase 2/3 study in hospitalized patients with severe COVID-19 (NCT04467840) is almost 100% complete. RHB-107's Phase 2/3 study is ongoing in non-hospitalized patients with symptomatic COVID-19 (NCT04723527) who do not require supplemental oxygen. Together, this covers potential treatment for the vast majority of affected patients.

In view of the upcoming completion of enrollment, RedHill is evaluating the regulatory path for opaganib with a focus on those countries currently most affected by COVID-19. The regulatory path, including potential submissions of emergency use applications in those countries, is subject to whether the data generated by the ongoing Phase 2/3 study is sufficiently positive and supportive as well as the specific requirements in each country. The strength of the safety and efficacy data generated from the opaganib studies will be key to regulatory applications. Additional studies to support the potential of such applications and the use or marketing of opaganib are likely to be required. For example, the FDA has indicated we will need to complete additional studies to support applications in the U.S. Evaluations and discussions continue with the FDA, EMA and regulators in other countries.

About Opaganib (Yeliva?, ABC294640)

Opaganib, a new chemical entity, is a proprietary, first-in-class, orally-administered, sphingosine kinase-2 (SK2) selective inhibitor, with dual anti-inflammatory and antiviral activity, that targets a host cell component of viral replication, potentially minimizing the likelihood of viral resistance. Opaganib has also shown anticancer activity and has the potential to target multiple oncology, viral, inflammatory, and gastrointestinal indications.

Opaganib is being evaluated as a treatment for COVID-19 pneumonia in a global Phase 2/3 study and has demonstrated positive safety and efficacy signals in preliminary top-line data from a 40-patient U.S. Phase 2 study.

Opaganib has also received Orphan Drug designation from the U.S. FDA for the treatment of cholangiocarcinoma and is being evaluated in a Phase 2a study in advanced cholangiocarcinoma and in a Phase 2 study in prostate cancer.

Opaganib demonstrated potent antiviral activity against SARS-CoV-2, the virus that causes COVID-19, completely inhibiting viral replication in an in vitro model of human lung bronchial tissue. Additionally, preclinical in vivo studies have demonstrated opaganib's potential to ameliorate inflammatory lung disorders, such as pneumonia, and has shown decreased fatality rates from influenza virus infection and ameliorated Pseudomonas aeruginosa-induced lung injury by reducing the levels of IL-6 and TNF-alpha in bronchoalveolar lavage fluids[3].

Originally developed by Apogee Biotechnology Corp., opaganib's development has been supported by grants and contracts from U.S. federal and state government agencies awarded to Apogee Biotechnology Corp., including from the NCI, BARDA, the U.S. Department of Defense and the FDA Office of Orphan Products Development.

The ongoing studies with opaganib are registered on www.ClinicalTrials.gov, a web-based service by the U.S. National Institute of Health, which provides public access to information on publicly and privately supported clinical studies.   

About RHB-107 (upamostat)

RHB-107 is a proprietary, first-in-class, orally-administered potent inhibitor of several serine proteases, with antiviral and potential tissue-protective effects. RHB-107 targets human cell factors involved in preparing the spike protein for viral entry into target cells and is therefore expected to be effective against emerging viral variants with mutations in the spike protein. RHB-107 is being evaluated in a U.S. Phase 2/3 study for treatment of non-hospitalized patients with symptomatic COVID-19 who do not require supplemental oxygen. In addition, RHB-107 has potential in targeting cancer, inflammatory lung diseases and gastrointestinal diseases. RHB-107 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 (including Hong Kong, S.A.R., China, Taiwan, China and Macau, S.A.R., China Region), from Germany's Heidelberg Pharmaceuticals (FSE: HPHA) (formerly WILEX AG) for all indications.

About RedHill Biopharma    

RedHill Biopharma Ltd. (Nasdaq: RDHL) is a specialty biopharmaceutical company primarily focused on gastrointestinal and infectious diseases. RedHill promotes the gastrointestinal drugs, Movantik? for opioid-induced constipation in adults[4], Talicia? for the treatment of Helicobacter pylori (H. pylori) infection in adults[5], and Aemcolo? for the treatment of travelers' diarrhea in adults[6]. RedHill's key clinical late-stage development programs include: (i) RHB-204, with an ongoing Phase 3 study for pulmonary nontuberculous mycobacteria (NTM) disease; (ii) opaganib (Yeliva?, ABC294640), a first-in-class SK2 selective inhibitor targeting multiple indications with positive Phase 2 COVID-19 data and an ongoing Phase 2/3 program for COVID-19 and Phase 2 studies for prostate cancer and cholangiocarcinoma ongoing; (iii) RHB-107 (upamostat), a serine protease inhibitor in a U.S. Phase 2/3 study as treatment for symptomatic COVID-19, and targeting multiple other cancer and inflammatory gastrointestinal diseases; (iv) RHB-104, with positive results from a first Phase 3 study for Crohn's disease; (v) RHB-102 (Bekinda?), with positive results from a Phase 3 study for acute gastroenteritis and gastritis and positive results from a Phase 2 study for IBS-D; and (vi) RHB-106, an encapsulated bowel preparation.