Merck Says Preliminary Trial Findings of Oral COVID-19 Drug Encouraging

A month and a half ago, US pharma giant Merck announced its decision to withdraw from the vaccine race as two of its candidates disappointed with unimpressive outcomes. Early trial data showed that both candidates demonstrated inferior immune responses as compared to other vaccines or natural SARS-CoV-2 infection.

However, the company still counted on its oral, broad-spectrum antiviral, molnupiravir (MK-4482/EIDD-2801), to contribute to the fight against COVID-19. Molnupiravir is a ribonucleoside analog inhibitor of influenza viruses repurposed to combat SARS-CoV-2. Presently, it is evaluated in two Phase 2a studies — NCT04405570 and NCT04405739 clinical trials.

On March 6th, the drugmaker announced that the investigational drug returned encouraging preliminary results from the Phase 2a trial (NCT04405570), where it showed a significant reduction of the virus in patients. The findings were presented at the 2021 Conference on Retroviruses and Opportunistic Infections (CROI 2021).

“The secondary objective findings in this study, of a quicker decrease in infectious virus among individuals with early COVID-19 treated with molnupiravir, are promising and if supported by additional studies, could have important public health implications, particularly as the SARS-CoV-2 virus continues to spread and evolve globally,” said Dr. William Fischer, lead investigator of the study and Associate Professor of Medicine at the University of North Carolina School of Medicine.

Collaboration with Ridgeback Bio

In May 2020, Merck signed a collaboration agreement with Ridgeback Biotherapeutics LP, a privately held biotech headquartered in Miami, to develop the antiviral drug. As per the terms, Ridgeback Bio stood to receive an upfront payment, milestone payments, and shares from the eventual sales of the drug, if approved.

Merck, on the other hand, will gain exclusive worldwide rights to develop and commercialize the drug and will be responsible for clinical development, regulatory filings, and manufacturing. Ridgeback Bio is not new to drug development. Last December, the Miami biotech received FDA authorization for Ebanga, an Ebola drug it licensed from NIH.

“We are very pleased to share our initial Phase 2 infectivity data at this important conference, which remains at the forefront for critical clinical scientific information in infectious diseases,” said Dr. Wendy Painter, Chief Medical Officer of Ridgeback Bio. “At a time where there is an unmet need for antiviral treatments against SARS-CoV-2, we are encouraged by these preliminary data.”

At present, Gilead Sciences’ Remdesivir is the only antiviral to have received emergency approval for COVID-19 treatment. However, if approved, molnupiravir will become the first oral antiviral for the disease. The drug is also presently evaluated in a Phase 2/3 trial (NCT04575584), which will be completed in May.

“We continue to make progress in our Phase 2/3 clinical programs evaluating molnupiravir in both outpatient and hospital settings and plan to provide updates when appropriate,” said Dr. Roy Baynes, Senior Vice President and Head of Global Clinical Development, Chief Medical Officer, Merck Research Laboratories.

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Author

Rajaneesh K. Gopinath