Chinese company Kintor Pharmaceutical has enrolled and dosed the first subject in the Phase III clinical trial of proxalutamide (GT-0918) for treating male patients with mild or moderate Covid-19 symptoms, in the US.

A nonsteroidal antiandrogen, proxalutamide is a selective high-affinity silent antagonist of the androgen receptor being developed for treating Covid-19, prostate cancer, and breast cancer.

The randomised, double-blind, placebo-controlled, multi-regional pivotal Phase III trial will assess the efficacy and safety of proxalutamide in male outpatients with mild or moderate symptoms of Covid-19.

Kintor noted that the percentage of hospitalisation events, including death, by day 28 will form the trial’s primary endpoint.

Secondary endpoints include the proportion of mortality by day 28, percentage of subjects meeting each clinical status on day seven, 14 and 28 using the National Institute of Allergy and Infectious Diseases (NIAID) eight-point scoring scale.

Kintor Pharmaceutical chief medical officer Dr Xunwei Dong said: “Initiation of this Phase III study of proxalutamide in male with mild or moderate Covid-19 symptoms in the US and other countries is a key milestone in fulfilling our mission to discover and develop effective therapies for Covid-19.

“We have been actively initiating MRCT Phase III trials in the US, the EU, South Africa and South America including Brazil.

“We will keep close communications with the US FDA and other local regulatory authorities, and complete this pivotal study with high quality and efficiency.”

Last month, the company reported top-line results from its investigator-initiated trial of proxalutamide in Brazil, which showed a 92% reduction in mortality in hospitalised Covid-19 patients.

The preliminary analysis data from this trial showed a mortality rate of 3.7% in the proxalutamide arm versus 47.6% in the control arm on day 14.