The US Food and Drug Administration (USFDA) on October 22 gave its final nod to Gilead's antiviral drug Remdesivir for treating hospitalised Covid-19 patients. Remdesivir is the first approved Covid-19 treatment in the United States.
There are no USFDA-approved drugs for the treatment of COVID-19. On May 1, 2020, the USFDA issued an Emergency Use Authorization (EUA) for Remdesivir sold under brand name Veklury for the treatment of laboratory confirmed Covid-19 in adult and pediatric patients hospitalized with severe disease.
The agency concluded that Remdesivir demonstrated efficacy in treating hospitalized patients with Covid-19.
US approval comes despite Remdesivir failing to show any benefit in reducing mortality or reducing number of hospital days in the WHO's Solidarity Trial.
Read here about what Solidarity Trial says about Remdesivir.
Frequently Asked Questions
A vaccine works by mimicking a natural infection. A vaccine not only induces immune response to protect people from any future COVID-19 infection, but also helps quickly build herd immunity to put an end to the pandemic. Herd immunity occurs when a sufficient percentage of a population becomes immune to a disease, making the spread of disease from person to person unlikely. The good news is that SARS-CoV-2 virus has been fairly stable, which increases the viability of a vaccine.
There are broadly four types of vaccine — one, a vaccine based on the whole virus (this could be either inactivated, or an attenuated [weakened] virus vaccine); two, a non-replicating viral vector vaccine that uses a benign virus as vector that carries the antigen of SARS-CoV; three, nucleic-acid vaccines that have genetic material like DNA and RNA of antigens like spike protein given to a person, helping human cells decode genetic material and produce the vaccine; and four, protein subunit vaccine wherein the recombinant proteins of SARS-COV-2 along with an adjuvant (booster) is given as a vaccine.
Vaccine development is a long, complex process. Unlike drugs that are given to people with a diseased, vaccines are given to healthy people and also vulnerable sections such as children, pregnant women and the elderly. So rigorous tests are compulsory. History says that the fastest time it took to develop a vaccine is five years, but it usually takes double or sometimes triple that time.
"The FDA is committed to expediting the development and availability of Covid-19 treatments during this unprecedented public health emergency,” said FDA Commissioner Stephen Hahn, in a statement.
“Today’s approval is supported by data from multiple clinical trials that the agency has rigorously assessed and represents an important scientific milestone in the Covid-19 pandemic," he added.
The approval of Remdesvir was supported by the agency’s analysis of data from three randomized, controlled clinical trials that included patients hospitalized with mild-to-severe COVID-19.
The USFDA does have certain limitations on the drug. Remdesivir is not yet approved for children under 12 years old. The USFDA noted in its review that there still wasn’t good data on how the drug would affect children, people who are pregnant, or anyone with kidney or liver issues, and it also mentions that there isn't good data on interactions between drugs.
USFDA identified hepatotoxicity as major safety issue with the drug.
Remdesivir works by blocking viruses from making copies of themselves. It was first developed by Gilead to treat Ebola and research over the past few years showed that it could block the coronaviruses SARS and MERS from replicating inside cells.
Solidarity trial design not rigorous
USFDA said it based its approval on three randomized, controlled clinical trials that included patients hospitalized with mild-to-severe Covid-19 .
This included the ACTT-1 trial sponsored by National Institute of Allergy and Infectious Disease (NIAID) and the “SIMPLE” trials sponsored by Gilead Sciences Inc.
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The agency said it found the most compelling evidence of effectiveness was provided by the NIAID-sponored ACTT-1 trial, with its rigorous trial design.
"While both the SOLIDARITY trial and the ACTT-1 trial contribute to our understanding of interventions to help treat COVID-19, the two clinical trials had different trial designs and primary goals," said USFDA.
The design of ACTT-1 (i.e., randomized, placebo-controlled, double-blinded) was better suited to rigorously assess a time to recovery endpoint compared to a trial with an open-label design, such as the SOLIDARITY trial, the agency said.
"Based on the findings of the ACTT-1 trial, benefit to patients for Veklury was demonstrated including a shorter time to recovery and better odds of clinical improvement. The SOLIDARITY results do not refute
these findings of benefit to patients," it added.
The ACTT-1 trial has found that Remdesivir has cut the hospital days by 5 days.