RedHill Biopharma Ltd., a specialty biopharmaceutical company, announced study results in which opaganib, a leading oral drug candidate for hospitalized patients with moderate to severe COVID-19, was observed to have potent in vitro efficacy against the Omicron SARS-CoV-2 variant while maintaining host cell viability.
Based on the new and previously announced data, opaganib’s unique human host-targeted, dual antiviral, and anti-inflammatory suggested mechanism is expected to act independently of viral spike protein mutations and remain effective against Omicron sub-variants BA.2, XE, and other emerging and future variants.
Work on testing opaganib against Omicron was conducted by the Centre for Immunology and Infection (C2i), The University of Hong Kong’s world-renowned infectious diseases research center, School of Public Health, by Dr. Michael Chan, Principal Investigator, of the Centre for Immunology and Infection, who said:
The results of this study showed opaganib exerting potent inhibition of Omicron SARS-CoV-2 variant viral replication in a model that we believe comes as close as currently possible to representing the Omicron clinical pathophysiological pathway. These are highly promising results that lend further weight to opaganib’s hypothesized host-mediated antiviral activity and expected effect irrespective of viral variant.
Reza Fathi, PhD., RedHill’s Senior VP, R&D, said:
Opaganib was tested for inhibition of Omicron SARS-CoV-2 viral replication using an ex vivo human respiratory explant model, a methodology based on the finding that Omicron has a replication advantage in respiratory tract explants culture. The results of the study, led by Dr. Chan, one of the leading experts in the field who’s extensive COVID-19-related research is widely published in top tier journals such as Nature, are encouraging. The results are also consistent with findings from the Phase 2/3 study in which opaganib was shown, together with reducing mortality in key subpopulations and improving the time to recovery, to accelerate viral RNA clearance by more than 4 days, even in an advanced patient population with a median of 11 days from onset of symptoms – we believe a likely first for a novel oral therapy in this underserved hospitalized moderate to severe COVID-19 patient population.
Opaganib was studied in a global Phase 2/3 study in hospitalized patients with severe COVID-19 pneumonia. In a prespecified analysis of all Phase 2/3 study patients with positive PCR at screening, opaganib improved the median time to viral RNA clearance by at least 4 days, achieving viral RNA clearance in a median of 10 days, while the median for clearance was not reached by the end of 14-days treatment in the placebo arm (Hazard Ratio 1.34; nominal p-value=0.043, N=437/463). Additional prespecified analyses in key subpopulations from the Phase 2/3 study also demonstrated a 70% reduction in mortality and a 34% benefit in time to recovery for patients treated with opaganib.
Regulatory submissions and discussions in the U.S., Europe, UK and additional countries are progressing regarding confirmatory data requirements and pathways to potential approval.