Pfizer holding on tight to supplies of COVID-19 drug Paxlovid, limiting the prospect of combination research: report

Pfizer is reportedly keeping Paxlovid all to itself, in terms of research supplies anyway.

The pharma giant is resisting requests from researchers for study supplies of the pill and hasn’t started or participated in any combination trials, Bloomberg reports. Researchers say getting study supplies of Paxlovid could help them improve the drug's effectiveness and fight the looming problem of drug resistance.

The company’s scientists have said one of their goals in developing COVID-19 treatments is minimizing the chance of drug resistance, when the virus evolves to evade existing vaccines and therapies.

Mutations have already affected Pfizer and BioNTech’s COVID-19 vaccine and others. Derek Lowe, a medicinal chemist and industry blogger, is surprised combination trials aren’t underway and told Bloomberg that resistance to Paxlovid is “likely just a matter of time.”’

Some researchers are taking a harder stance. Reshma Ramachandran, a postdoctoral fellow in Yale University’s National Clinician Scholars Program, called Pfizer’s reluctance to share “disturbing.”

Viruses such as SARS-CoV-2 constantly mutate. Other RNA viruses like HIV have a proven resistance that is hard to tackle. HIV became consistently resistant to treatments until combinations were introduced in the 1990s.  

Pfizer believes the drug's short treatment duration and high concentrations “suggest the chances of resistance are minimized,” a spokesperson told Bloomberg. The company is monitoring mutations in patients and will use the findings to design second-generation drugs, the spokesperson added.

Some researchers aren’t satisfied with this conclusion and say combinations are an important component of keeping resistance at bay.  

Putting multiple drugs together is “like hitting the virus factory at two different points in the assembly line,” Stephan Polyak, a virologist at the University of Washington in Seattle, told the news service.

For his part, Pfizer CEO Albert Bourla agreed that combination studies might make sense at some point, but that it's not an immediate priority, Bloomberg reports.

Pfizer plans to test a next-generation Paxlovid-style compound later this year that eliminates the need for ritonavir, a medication that’s paired with the main active ingredient in the combination drug.

Pfizer won FDA authorization for Paxlovid late last year and expects $22 billion in global sales from the drug this year.