(Bloomberg) — A Chinese drugmaker said it has started mass-producing an experimental drug from Gilead Sciences Inc. that has the potential to fight the novel coronavirus, adding to concerns that the American drug giant is losing patent control in China’s accelerating effort to fight the outbreak.Suzhou-based BrightGene Bio-Medical Technology Co. said in a statement filed to the Shanghai Stock Exchange on Tuesday night that it has developed the technology to synthesize the active pharmaceutical ingredients of remdesivir, Gilead’s drug that is a leading candidate to treat the highly-infectious virus that’s killed more than 1,000 people. The drug isn’t licensed or approved anywhere in the world yet.China Wants to Patent Gilead’s Experimental Coronavirus Drug (3)Its stock rose 20% on Wednesday in Shanghai.While BrightGene said that it intends to license the drug from Gilead, its move to start manufacturing at this early stage is highly unusual and a potential infringement of the American company’s intellectual property. It comes a week after Chinese researchers filed an application to patent the drug to treat the new coronavirus, a bid that would give China sway over the global use of the therapy to fight the outbreak.“In general, production constitutes a patent infringement, but there’s an exception if the production is intended only for regulatory approval and not for sale in the market,” said Wang Yanyu, a Beijing-based partner specializing in intellectual property at AllBright Law Offices.Large areas of China have been paralyzed by the coronavirus epidemic, and Gilead’s drug is seen as a potential breakthrough after it showed signs of working on infected patients in the U.S. Chinese researchers are now testing the drug on 761 patients in clinical trials in Wuhan.BrightGene said it will have to license the patent from Gilead, conduct clinical trials and procure regulatory approvals before it can sell the drug on the market. The technology it developed to make remdesivir may not be of much value if the drug fails to produce ideal results from the ongoing clinical trials, or if the epidemic comes under control soon, it said.Gilead did not immediately respond to a request for comment on BrightGene’s announcement. Last week, the company said it invented remdesivir and has patented it in China, including filing patent applications for use on coronaviruses. The company also said that it is working with Chinese, U.S. and World Health Organization officials to rapidly determine whether the drug can be used to treat the virus.BrightGene did not immediately respond to Bloomberg queries on its remdesivir production.(Adds lawyer comment in fifth paragraph)To contact Bloomberg News staff for this story: Dong Lyu in Beijing at firstname.lastname@example.orgTo contact the editors responsible for this story: Rachel Chang at email@example.com, Sharon ChenFor more articles like this, please visit us at bloomberg.comSubscribe now to stay ahead with the most trusted business news source.©2020 Bloomberg L.P.