Convalescent plasma (CP) therapy failed to benefit coronavirus ( COVID-19 ) patients, the largest trial conducted across 39 hospitals in India and spearheaded by the Indian Council of Medical Research (ICMR) found.
The trial spanning April-July enrolled 464 hospitalised patients with “moderate” COVID-19 and administered convalescent plasma — antibodies derived from plasma filtered from the blood of those who have recovered from COVID-19 — on some of them.
Last week, ICMR Director General Balram Bhargava had said that the trial had been completed and results were expected soon .
The idea was that such antibodies would neutralise replicating viruses and check the growth of the infection.
However, in the 235 patients that received the plasma along with the “best standard of care” (called the intervention arm) and the 229 patients that received only the “standard of care” (called the control arm), there was not a significant difference in the proportion of those who did not progress to severe illness over 28 days, nor did the trial save a significant fraction of patients from death.
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“Thirty-four patients (13.6%) died in the intervention arm and 31 (14.6%) in the control arm,” the report noted.
No reduction in deaths
“CP was not associated with reduction in mortality or progression to severe COVID-19. This trial has high generalisability and approximates real-life setting of CP therapy in settings with limited laboratory capacity,” the authors concluded. The findings were reported in preprint repository MedRxiv, meaning that the report has not yet been peer-reviewed in a medical journal.
The PLACID trial, as it is called, was an open-label (patients know the nature of treatment they are getting), parallel-arm, Phase 2, multi-centre, randomised, controlled trial conducted in 39 tertiary care hospitals across India. Of these, 29 were teaching public hospitals and 10 were private hospitals spread across 14 States and Union Territories, and representing 25 cities.
The results from the study mirror previous international findings from CP that failed to find a measurable benefit.
These findings are sobering compared to claims by political parties of CP being a lifesaver. Delhi Chief Minister Arvind Kejriwal has said that plasma therapy was a “crucial” prong in Delhi’s fight against COVID-19. U.S. President Donald Trump too had praised plasma therapy. The head of the United States’ medical regulator, the Food and Drug Administration, apologised for hyping the benefits of CP after the organisation approved the use of it as a treatment under the emergency use authorisation.
ICMR guidelines currently leave it to medical practitioners to administer CP in case of moderately ill COVID-19 patients. The initial promise of the therapy had led to a frantic rush in many hospitals where patients were asked to source, using their own means, CP from those who had recovered from COVID-19.
The study’s authors said that the use of CP appeared to mitigate shortness of breath and fatigue among patients, and did correspond to a “higher negative conversion of viral RNA”, but ultimately did not improve outcomes over the period of evaluation.
“Use of CP as a treatment modality for COVID-19 has received authorisation for off-label use in India. This authorisation has been paralleled by questionable practices such as calls for donors on social media, and the sale of CP on the black market with exorbitant price tags in India. CP is a safe therapeutic modality, plasmapheresis, plasma storage and Nab (neutralising antibody) measurement are all resource-intensive processes, with limited number of institutes in the country having the capacity to undertake these activities in a quality-assured manner,” the authors underscored.