- US regulator says lack of scientific evidence to prove HCQ's effectiveness
- Also warns not to use HCQ with Remdesivir, another anti-viral made by the US company Gilead Life Sciences
- Zydus Cadila and IPCA Laboratories are the largest makers of the drug
- FDA had granted emergency use authorisation for HCQ on March 28
The US Food and Drug Administration (FDA) has revoked the emergency use authorisation (EUA) given to anti-malarial drugs chloroquine phosphate and hydroxychloroquine sulfate (HCQ) in treating Covid-19 patients, citing lack of scientific evidence to prove its effectiveness and potential side effects.
Indian companies Zydus Cadila and IPCA Laboratories are the largest makers of this drug, touted by the US President Donald Trump as a potential 'game changer' in containing Covid-19. The Indian drug makers supply over 70 percent of the global demand for HCQ, and had increased their capacities several times to meet the demand for Covid-19 treatment globally.
In a related development, the FDA also warned healthcare professionals of a 'newly discovered potential drug interaction' when chloroquine phosphate and hydroxychloroquine sulfate is used with Remdesivir, another drug which recently got EUA from the US FDA for Covid-19 treatment. It says the combined use may reduce antiviral activity of Remdesivir, a drug under development manufactured by the US drug maker Gilead Life Sciences. About six Indian companies like Cipla, Jubilant, Hetero, Syngene, Dr Reddy's and Zydus Cadila were licensed to make and distribute the drug in over 120 geographies.
"In light of ongoing serious cardiac adverse events and other potential serious side effects, the known and potential benefits of chloroquine and hydroxychloroquine no longer outweigh the known and potential risks for the authorised use", the FDA said. The FDA had granted the EUA on March 28 'based on the science and data available at the time'.
The Biomedical Advanced Research and Development Authority (BARDA) within the US Department of Health and Human Services originally requested the EUA covering chloroquine and hydroxychloroquine at that time. Currently, the BARDA sent a letter to the FDA requesting revocation of the EUA based on 'up to date science and data', the FDA reasoned.
Recent results from a large randomised clinical trial in hospitalised patients, a population similar to the population for which chloroquine and hydroxychloroquine were authorised for emergency use, demonstrated that hydroxychloroquine showed no benefit on mortality or in speeding recovery. This outcome was consistent with other new data, including data showing that the suggested dosing regimens for chloroquine and hydroxychloroquine are unlikely to kill or inhibit the virus that causes COVID-19. The totality of scientific evidence currently available indicate a lack of benefit, the regulator said.
Chloroquine and hydroxychloroquine are both FDA-approved to treat or prevent malaria. Hydroxychloroquine is also approved to treat autoimmune conditions such as chronic discoid lupus erythematosus, systemic lupus erythematosus in adults, and rheumatoid arthritis. Both drugs have been prescribed for years to help patients.