China approves flu drug being touted as a potential coronavirus treatment amid a rush of clinical studies
One of the three drugs that China’s Ministry of Science and Technology has tapped as potential COVID-19 treatments to watch has notched its first Chinese OK — for the flu.
While there’s no proof yet that fapilavir, or favipiravir, is the cure that patients and physicians are yearning for, it stands out for a unique constellation of qualities. It’s been commercially available in Japan for several years (unlike Gilead’s experimental remdesivir) yet it’s new to China (unlike the malaria drug chloroquine phosphate). Perhaps more importantly, a domestic biotech — Zhejiang Hisun Pharma — owns the rights to manufacture and market the drug, preempting any concerns about patents.
At the same time, the Ministry of Science and Technology suggested that chloroquine phosphate, a 70-year-old drug, should be included in the standard regimen after showing promising results in trials across 10 hospitals.
Clinical guidelines for the treatment of respiratory illnesses resulting from the new coronavirus originating from Wuhan, now named SARS-CoV-2, are evolving quickly while development of a vaccine to prevent people from getting infected in the first place speeds ahead. On Tuesday Sanofi announced that its Pasteur unit will investigate a preclinical vaccine they made for SARS years ago, to see if it can protect against COVID-19.
BARDA is a collaborator for the effort, which will also see Sanofi deploying its recombinant DNA platform to produce the vaccine.
Like remdesivir, fapilavir attacks RNA viruses by inhibiting RdRp (RNA-dependent RNA polymerase). Fujifilm subsidiary Toyama Chemical first notched an approval in Japan in 2014 and christened it Avigan; in 2016 it licensed China API rights to Hisun — shortly afterward, Toyama also supplied the drug for an Ebola study that didn’t lead anywhere.
Combating the flu remained fapilavir’s raisons d’être, and officially it’s sanctioned for adults with novel or recurring strains of influenza when other treatments have failed. But Hisun’s Yue Li told PharmCube that the OK means physicians can prescribe the drug on a compassionate use basis.
Along with the flu approval, the National Medical Products Administration also gave the green light on an IND to test fapilavir against SARS-CoV-2.
Two hospitals in Shenzhen and Hangzhou have begun their own trials comparing fapilavir against other potential treatments, according to a Chinese registry of clinical trials. Other compounds under consideration include Kaletra (lopinavir/ritonavir), an HIV drug owned by AbbVie; Roche’s new flu drug Xofluza; and nebulized alpha-interferon.
Last Friday Shenzhen Third People’s Hospital suggested that fapilavir had better antiviral activity and less side effects than Kaletra, based on an 80-patient study.
That puts fapilavir on the same path as remdesivir, for which clinical trials were recently kicked off. But stringent screening requirements may be slowing down the highly anticipated study, the Wall Street Journal reported. The trials have only recruited fewer than 200 people out of the target 700 plus since February 5, who couldn’t have taken other medications in the prior 30 days and must have lab confirmed diagnoses.
The Gilead drug was viewed as a top contender in the rush to find effective therapies for COVID-19, as it’s been tested in humans as part of an Ebola trial. In fact, it appears so promising that the Wuhan Institute of Virology has tried to patent its use against the new coronavirus while Suzhou-based BrightGene said it’s mass-producing the active pharmaceutical ingredient and ramping up production of the actual drug — with plans to license it from Gilead.
For its part, the US drugmaker said it’s focused on helping determine the efficacy of remdesivir ensuring manufacturing capacity in case of approval.
Researchers, clinicians and drugmakers are pulling out all the stops to help treat and contain a viral disease that’s sickened more than 73,000 worldwide and taken 1,875 lives. Despite the lack of proven treatments, 13,116 patients have reportedly recovered.
Japan, which had seen its caseload rise dramatically due to a stream of confirmed cases on the Diamond Princess cruise ship now docked at the port of Yokohama, said it is working to launch its own trials with HIV drugs.