Anvisa authorizes phase 3 clinical trial with proxalutamide for treatment of Covid-19

RIO DE JANEIRO, BRAZIL – Brazil’s national health regulatory agency Anvisa authorized on Monday, 19, a clinical trial to evaluate the safety and efficacy of the drug proxalutamide in the treatment of Covid-19. The study will involve 12 volunteers from the state of Roraima and another 38 from São Paulo.

Anvisa advised that the study is a phase III, randomized, double-blind, placebo-controlled trial. The substance will be given to male outpatient participants with mild to moderate Covid-19 symptoms. There is no proof yet of the drug’s effectiveness in treating covid and it should not be used for this purpose, according to the agency.

The clinical trial is sponsored by Suzhou Kintor Pharmaceuticals, a company based in China. In addition to Brazil, trials will also be conducted in Germany, Argentina, South Africa, Ukraine, Mexico, and the United States.

The drug has been advocated by President Jair Bolsonaro and people close to him since March. At the time, a group of researchers had presented data from a study with proxalutamide done in the Amazon.

The tests were not detailed in a scientific article or analyzed by independent scientists, but Congressman Eduardo Bolsonaro, son of the president, made a post on his Twitter praising the preliminary results of the research.

In an interview with Estadão Verifica in March, one of the study’s co-authors, Carlos Wambier, said that the researchers did not confirm that proxalutamide is a cure for covid-19.

Wambier is an assistant professor in the Department of Dermatology at Brown University in the US. He said that more research on the drug is still needed, including to validate whether the same effect can be observed in different populations and with viral variants.

A month later, in April, the president talked about the supposed benefits of the drug in a live broadcast on his Facebook page with Dr. Helio Angotti Neto, national secretary of Science, Technology, Innovation, and Strategic Inputs in Health of the Ministry of Health. At the time, Angotti said that the drug showed “much promise”, although admitting there were no published clinical studies to prove the claim.

On Sunday, July 18, upon leaving Vila Nova Star Hospital, where he was hospitalized with a condition of intestinal obstruction, the chief executive spoke again about the drug. “There is something that I’ve been following for some time, and we have to study it here in Brazil, it’s called proxalutamide,” he stated. The president mentioned that he would ask for an investigation of the drug.

PROXALUTAMIDE

Proxalutamide is a nonsteroidal antiandrogen (NSAA) – specifically, a selective high-affinity silent antagonist of the androgen receptor – which is under development by Suzhou Kintor Pharmaceuticals, a subsidiary of Chinese Kintor Pharmaceutical Limited, for the potential treatment of COVID-19, prostate cancer, and breast cancer.

Proxalutamide is in phase III studies for mCRPC as monotherapy against prostate cancer and in combination with abiraterone. In the United States, it is in a phase II study as monotherapy for mCRPC.