India Study of Convalescent Plasma Shows ‘Limited Effectiveness’ for COVID-19 Patients

An Indian trial evaluating convalescent plasma as a COVID-19 treatment has found that the therapy failed to reduce progression to severe COVID-19 or death, leaving the Indian government skeptical about its viability, though medical experts say the treatment may still hold promise.

The results of the 464-participant trial, published Friday in The BMJ, showed that the treatment didn’t help to reduce progression to severe COVID-19 or death in hospitalized adults. Specifically, participants received two 200-milliliter doses of convalescent plasma a day apart along with standard of care, but no difference was observed in 28-day mortality or progression to severe disease, the researchers said. They noted the treatment was associated with a higher resolution of shortness of breath and fatigue on day seven.

“The intervention did not … show anti-inflammatory properties as we could not detect any difference in the levels of inflammatory markers,” they said. Overall, the researchers concluded that convalescent plasma “showed limited effectiveness” for moderate COVID-19 patients.

The findings may convince the Indian government to nix the therapy from its national guidelines, according to Indian media reports, which said that the government is leaning toward removing it after hearing of the trial’s results.

Medical experts, however, argue the therapy shouldn’t be abandoned just yet despite the discouraging results. Eric Topol, founder and director of the Scripps Research Translational Institute, contended that the Indian trial was underpowered for detecting mortality and called for a larger randomized clinical trial to get a more definitive answer on the treatment’s efficacy.

Arturo Casadevall, chair of Johns Hopkins Bloomberg School of Public Health’s Department of Molecular Microbiology and Immunology, warned against drawing many conclusions based on the trial, noting that it involved late use of the therapy and units with low antibody levels.

“Other studies associate reductions in mortality with earlier therapy using high titer units,” Casadevall said. “There is little we can conclude from this [trial]. Despite handicapping plasma with late usage and low antibody titers, this [trial] still measured a beneficial effect for plasma – arguably comparable to remdesivir, which has not been shown to reduce mortality.”

Convalescent plasma is currently authorized as a COVID-19 treatment for hospitalized patients in the U.S. under an Emergency Use Authorization, though it drew controversy following FDA Commissioner Stephen Hahn’s misrepresentation of the drug’s benefits in announcing the EUA (DID, Aug. 26). Hahn later apologized for the error.

To date, only one treatment, remdesivir, has been granted full approval from the FDA for COVID-19 (DID, Oct. 23). — James Miessler