Covid-19 roundup: Valneva defends vaccine in wake of unflattering booster study; Merck goes after Pfizer’s new antiviral — report
Falling way behind the frontrunners in delivering a Covid-19 vaccine, French biotech Valneva has placed high hopes on boosters.
Which may be why it is reacting strongly to a study suggesting that its candidate, VLA2001, was the only one out of seven that didn’t work well as a booster for volunteers who had doses of the Pfizer/BioNTech mRNA shot.
The company is trying to fire back Monday morning, days after results from the COV-Boost study were published in The Lancet.
That trial, Valneva noted, was designed to help the UK government make a quick decision on the autumn booster campaign. In that spirit, participants were given a booster dose “relative early,” only two to three months after the second dose of the primary vaccination series. It found that while VLA2001 spiked antibody levels after two AstraZeneca/Oxford jabs, like all the others tested, it didn’t have the same effect following the Pfizer/BioNTech regimen.
“Valneva believes it is likely that the short interval between the second shot and booster shot could have adversely impacted the results for VLA2001, given that a longer interval is generally required for inactivated vaccines,” the company wrote.
Investigators in the trial measured immunity in terms of antibody levels, they added, which is at most a marker of immune response rather than vaccine effectiveness.
“The setting in the study leads us to believe that COV-Boost does not allow any conclusions to be reached regarding the use of VLA2001 as a booster in a real-life setting,” Valneva CMO Juan Carlos Jaramillo said in a statement. “The protective antibody threshold has not yet been established therefore relative increases in antibody levels should not be seen as indicative of efficacy.” — Amber Tong
Merck goes after Pfizer’s new antiviral — report
After an FDA panel narrowly endorsed Merck’s molnupiravir in a 13-10 vote, Merck is offering a preemptive defense of its antiviral pill against a rival treatment from Pfizer.
According to Merck’s SVP of global medical affairs Eliav Barr, the fact that Pfizer’s new antiviral has to be taken with Pfizer’s ritonavir, an anti-HIV drug, would make the treatment “unsuitable” for patients with pre-existing conditions.
“The problem is that it’s [Ritonavir] incredibly non-specific,” Barr told the Financial Times. “So there’s a whole host of medicines that people take, especially those medicines, unfortunately, that are associated with conditions that confer risk.”
And while there was a study published in Nature about drug-on-drug interactions in patients treated with ritonavir and AbbVie’s lopinavir, Pfizer shot back, saying their drug is safe and any potential drug-drug interactions can be managed through dose-adjustment while on its antiviral.
The ball is now in regulators’ court. If the FDA grants the EUA for molnupiravir, the US government has a contract to buy 3.1 million courses for $2.2 billion. — Paul Schloesser
New WHO report sheds light on regulatory inner workings leading to speedy approvals
In hindsight, speedy reviews for Covid-19 vaccines and treatments — coupled with flexible arrangements taking into account pandemic restrictions — seem intuitive. But how exactly do they happen?
The WHO shed some light on the inner workings at regulatory authorities around the world in a new report released together with the International Coalition of Medicines Regulatory Authorities, after surveying multiple agencies and reviewing the practices — both regulatory flexibilities and extraordinary measures — they adopted.
The most common mechanisms offered by regulators include quick, frequent and continuous communications, which all 11 agencies surveyed said they put in place.
At the bottom of the list, meanwhile, were specific practices of relying on other countries for assessment of drugs and vaccines, such as participation in joint review programs and full or partial reliance.
“There has been extensive exchange of information on GMP compliance amongst International Regulators, paving the path for more reliance between International Partners,” the WHO and the ICMRA wrote. “Remote inspections have been a useful tool complementing GMP compliance verification.” They emphasized that instead of leading to a reduction in regulatory standards, these flexibilities and early approval actually reflected “greater process and product knowledge” that enabled manufacturers to leverage those flexibilities.
During a workshop they convened to exchange ideas, the institutions added that different stakeholders identified bottlenecks limiting the use of regulatory procedures. From the regulator’s perspective, limited or inadequate data, lack of engagement, limited capacity or resources and changing timetables made it difficult to apply special measures; whereas for the industry, lack of regulatory reliance, constraints of existing legislation, volume of questions, full national release testing of vaccines, expectations of complete dossier information and lack of clear communication pathways, among others, were key kindrances.