Israel-based RedHill Biopharma on Tuesday announced that its Covid pill Opaganib is expected to be unaffected by mutations associated with Omicron and other known Coronavirus' variants of concern.

Studies on Opaganib have shown an apparent clinical benefit in reducing mortality, getting patients back onto room air and getting them out of hospital faster.

Opaganib, if approved, would target an entirely different and sicker patient population than the Pfizer and Merck oral drug candidates, which showed benefit only in non-hospitalised patients at the earliest stages of symptomatic infection.

"Opaganib acts independently of mutations to the viral spike protein. We believe that its unique proposed mechanism of action -- targeting a protein in the human cell required by the virus for replication rather than the virus itself -- holds significant potential versus Omicron and other existing and emerging variants with mutations to the spike protein," the company said in a statement.

Data from the Opaganib Phase 2/3 study in moderate and severe Covid-19 patients is intriguing and suggests the possibility that Opaganib might prove itself as an effective anti-viral. In a subpopulation of patients defined as moderately severe based on their level of baseline oxygen supplementation, mortality was 62 per cent lower in those using Opaganib (16 per cent placebo vs. 6 per cent Opaganib).

The results suggest a sub-group of patients who would likely benefit from this therapy, and they highlight the need for additional studies in the development of this therapy.

"Omicron is just another reminder that Covid-19 is an endemic virus at this point, and it is not going away. The evolution of this virus will continue as long as it circulates, and we will need to continue to tweak our vaccines and monoclonal antibodies in order to respond to new variants as they arise," said Kevin Winthrop, Professor of Infectious Diseases at Oregon Health & Science University.

Further, the company said its another oral Covid-19 drug candidate RHB-107 is also independent of the mutations observed in the Omicron variant that are altering the spike-protein antigenic properties.

RHB-107 is currently being evaluated in a Phase 2/3 study in non-hospitalised Covid-19 patients in the US and in South Africa. The results are expected in the first quarter of 2022.

"Both opaganib and RHB-107 have unique human cell-targeted mechanisms of action that act independently of mutations at the spike protein. Given the gravity of the threat presented by Omicron, and the likely emergence of other variants, RedHill is pursuing development of these two promising Covid-19 pills as quickly and diligently as possible," said Gilead Raday, RedHill's Head of R&D.