US FDA revoked the authorization following a request from Gary Disbrow, acting director of the Biomedical Advanced Research and Development Authority (BARDA).
The US Food and Drug Administration (USFDA) on June 15 withdrew emergency use authorizations (EUA) for Chloroquine Phosphate (CQ) and Hydroxychloroquine Sulfate (HCQ), as the agency no longer believes the drugs may be effective in treatinag COVID-19 and side-effects outweigh any potential benefit.
USFDA revoked EUA following the request from Gary Disbrow, acting director of the Biomedical Advanced Research and Development Authority (BARDA).
"Today’s request to revoke is based on new information, including clinical trial data results, that have led BARDA to conclude that this drug may not be effective to treat COVID-19 and that the drug’s potential benefits for such use do not outweigh its known and potential risks," USFDA chief scientist Denise Hinton said in a letter.
"After reviewing new information from large randomised clinical trials the agency now believes that the suggested dosing regimens are unlikely to produce an antiviral effect," USFDA said.
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.
"Earlier observations of decreased viral shedding with HCQ or CQ treatment have not been consistently replicated and recent data from a randomized controlled trial assessing probability of negative conversion showed no difference between HCQ and standard of care alone," the regulatory agency said.
Current U.S. treatment guidelines do not recommend the use of CQ or HCQ in hospitalized patients with COVID-19 outside of a clinical trial, and the NIH guidelines now recommend against such use outside of a clinical trial.
Recent data from the RECOVERY trial sponsored by Oxford University in the United Kingdom in collaboration with several foundations and British government agencies, showed no evidence of benefit for mortality or other outcomes such as hospital length of stay or need for mechanical ventilation of HCQ treatment in hospitalized patients with COVID19.
The trial with over 11,000 patients announced closure on June 5, 2020, as the HCQ arm showed no benefit.
The age old drugs Chloroquine and its derivative Hydroxychloroquine used in treatment of malaria, lupus have become popular after US President Donald Trump hailed the medications as magic bullets for treating COVID-19. On March 28, USFDA granted EUA to CQ and HCQ, despite serious differences among the medical community about using this drug without data.
Countries including India have started using the drug for treating COVID-19 patients and also as prophylactic in high risk groups such as healthcare and other frontline workers to prevent the spread of infection. The government protocol on June 13 says the drug should be used as early in the disease course as possible to achieve any meaningful effects and should be avoided in patients with severe disease.
The US decision to revoke EUA to CQ and HCQ could likely to impact the drugs use. Indian companies like Zydus Cadila and Ipca, the largest producers of these drugs in the world, have benefited from the huge spike in demand.Follow our coverage of the coronavirus crisis here