With final phase 3 data in hand, Vir Biotechnology and GlaxoSmithKline are seeking full approval for their COVID-19 antibody by the end of the year. The study found that the treatment, sotrovimab, slashed hospitalizations and deaths by 79% in adults with mild to moderate COVID-19 who were at high risk of their disease becoming severe.
The duo scored an emergency nod from the FDA in May based on early data from nearly 600 patients. An interim analysis showed sotrovimab reduced the risk of hospitalization or death by 85% a month after treatment, prompting an independent data monitoring committee to recommend stopping enrollment in the study. The companies plan to submit the full data, from 1,057 patients, to a peer-reviewed journal.
In the 29 days after treatment, six patients who received the antibody (1%) died or were hospitalized for more than 24 hours, compared to 30 patients (6%) who received placebo, the partners said in a statement. But three of the six sotrovimab patients could have been hospitalized for reasons other than worsening COVID-19, such as lung cancer or a diabetic foot ulcer, they said in the statement.
The most common side effects were mild or moderate rash and diarrhea, affecting 1% and 2% of the sotrovimab group, respectively. No other side effects hit the sotrovimab group at a higher rate than the placebo group, the companies said.
Besides an upcoming FDA submission for sotrovimab, Vir and GSK are seeking approval for the antibody in Europe. The European Medicines Agency started a rolling review of the data in early May and issued a positive opinion on the drug two weeks later.
Vir and GSK's drug is trailing other anti-SARS-CoV-2 antibodies from Eli Lilly and Regeneron, which scored emergency nods late last year. However, those treatments have faced multiple challenges. First, supplies were going unused, partly because they must be given by intravenous infusion in a narrow time window after patients have begun showing symptoms. And second, the rise of SARS-CoV-2 variants has led the FDA to pull the emergency authorization for Lilly’s bamlanivimab as a solo therapy and federal officials to pause shipments of its bamlanivimab-etesevimab combo to Illinois based on its reduced potency against the P.1 variant, first identified in Brazil, and also called the gamma variant.
To tackle the first hurdle, the companies are working on a formulation of sotrovimab that can be given by intramuscular injection. It is in a phase 2 study due to read out by the end of the year and a phase 3 study with data expected in the first half of 2022. The partners are also planning a trial to test the intramuscular antibody’s efficacy at warding off COVID-19 infection.
As for the second hurdle, Vir and GSK have pitted the antibody against various circulating SARS-CoV-2 variants in lab dish experiments. The drug “appears to retain activity against current variants of concern and interest including B.1.1.7 (Alpha), B.1.351 (Beta), P.1 (Gamma), B.1.427/429 (Epsilon), and B.1.526 (Iota)," the National Institutes of Health (NIH) noted in its updated COVID-19 treatment guidelines.
The real test may well be against the looming delta variant, first seen in India, which has now taken hold in countries such as the U.K. as the dominant strain. How GSK and Vir's drug can hold up against this variant, which appears to spread much more quickly than the already rapid alpha and has some immune escape with possible risks of greater severity in disease, will likely be a larger test of its use in the coming months.