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Covid-19: Campaigners accuse Pfizer of blocking access to antiviral for trials in poorer countries

BMJ 2022; 376 doi: (Published 17 March 2022) Cite this as: BMJ 2022;376:o721
  1. Jacqui Thornton
  1. London

Pfizer has been accused of blocking “urgently needed” studies into the use of its novel oral antiviral drug for covid-19 combined with other medicines for use in low and middle income countries.

The Drugs for Neglected Diseases initiative (DNDi) expressed concern on behalf of a consortium of 26 African and global research bodies that the drug company would not provide access to Paxlovid.1 It said that the refusal to cooperate set a “dangerous precedent” given the number of other antivirals in the pipeline and that it was difficult to understand the rationale for the decision in a global pandemic.

At least three separate requests are understood to have been made to Pfizer, but despite several discussions a breakthrough has not been forthcoming. Around 1000 doses of the therapy would be required for the studies.

Michelle Childs is director of policy advocacy for DNDi, a non-profit research and development organisation that coordinates the ongoing Anticov clinical trial to find treatments for mild to moderate covid-19 cases in low and middle income countries.2

“It’s not our intention to have a massive confrontation,” she said. “We want to raise our concern and ask Pfizer to reconsider. We want to collaborate with everybody working in this space including Pfizer, and that would be the preferred option.”

Childs added that the reason given by Pfizer for the refusal was that the company intended to conduct its own similar studies. She said, “The difficulty is that we haven’t seen any clinical trial protocol and there doesn’t seem to be any publicly available information, for example, on To date they’ve declined to share their plans further.”

Treatment window

Paxlovid, a combination of nirmatrelvir and ritonavir, has emerged as one of the most promising antiviral treatments for outpatients with mild to moderate covid-19, reducing the risk of hospital admission or death by as much as 89% in patients at high risk of severe disease.3 The treatment must be taken within 3-5 days of symptom onset to be effective.

But an unpublished interim analysis done as part of the ongoing Anticov trial, conducted in 10 African countries, showed that more than half of the 1180 enrolled patients presented after day 5. This means that even in a clinical trial setting more than half of patients would not benefit, said DNDi.

Delays in presenting could be caused by a lack of access to covid testing, travel time to clinical trial sites, and varying awareness of having the illness. To overcome this challenge DNDi said that was necessary to explore whether using Paxlovid with other drugs such as anti-inflammatories or other antivirals could widen the treatment window to at least seven days.

DNDi and academic investigators from large university hospitals in Europe have separately approached Pfizer about potential collaborations on combination studies in low and middle income countries, but it said that Pfizer had declined to provide access to the drug for research purposes. Working with them would be the quickest and easiest solution, said Childs, as obtaining generic versions of the drug would encounter additional hurdles such as unclear licence terms and difficulty with bioequivalence.

Broader need

The consortium of research bodies includes the Infectious Diseases Data Observatory at the University of Oxford and FIND, the global alliance for diagnostics in Switzerland.

Nathalie Strub-Wourgaft, director of DNDi’s covid-19 response and one of the coordinators of the Anticov consortium, said, “It is difficult to understand any rationale for refusing to cooperate in the midst of a global pandemic, and this sets a dangerous precedent since there are many other promising antivirals in the pipeline and these novel treatments will also require follow-on research to determine their optimal use in resource limited settings.”

Childs said that companies may be reluctant to allow others to carry out clinical trials, particularly for a new product, because of concerns about adverse events or methods of testing.

“We understand those concerns, but we think that if you’re talking about research with organisations such as DNDi and others, who are reputable researchers with a track record of carrying out responsible research in a pandemic, then it is a situation where we think they should consider the broader need to answer the questions we have,” she said.

She added that a number of pressing unanswered research questions remained—not just how to potentially stretch the treatment window but also whether the combination could benefit immunosuppressed populations such as people with HIV and children who were malnourished. This was particularly important given the background of lack of access to vaccines in many low income countries, she said.

Pfizer said that it appreciated the importance of gathering additional data to help maximise the public health response to the covid-19 pandemic and that it was committed to studies that could provide data that would be accepted by global regulatory agencies.

In a statement to The BMJ the company said that it was “working continuously to expand our own supply chain while also licensing through the Medicines Patent Pool (MPP) to better reach the most vulnerable parts of the world. In addition to the MPP voluntary licensing agreement, Pfizer initiated bilateral outreach to over 100 countries, and we have now entered into agreements with multiple countries around the world.”

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