Gongda Xue, aged around 50 and living in Switzerland, is the brother of Yu Xue, a biochemist who last year pleaded guilty to stealing trade secrets from drugmaker GlaxoSmithKline (GSK).
Switzerland's federal justice office OFJ decided Friday that Gongda Xue, a researcher arrested on May 28, should be extradited in line with a Pennsylvania state court request.
He has 30 days to appeal, an OFJ spokeswoman, Ingrid Ryser, told the AFP news agency.
Yu Xue pleaded guilty to stealing trade secrets on GSK work in biopharmacy, notably for cancer treatments and other serious illnesses.
Five people have been charged in the case to date, including three who formed a Chinese-based startup, Renopharma, in the hope of allegedly benefiting from GSK's stolen proprietary data.
Federal prosecutors in Philadelphia have described Yu Xue, who worked for GSK between 2006 and 2016, as one of the world's top protein biochemists.
The prosecutors accuse Gongda Xue, who worked in Basel for the Friedrich Miescher Institute for Biomedical Research, of carrying out tests in Switzerland using data stolen from a GSK research centre in Pennsylvania.
A spokeswoman for the Swiss institute, Isabelle Baumann, indicated that Gongda Xue worked there “as a post-doctoral trainee between 2008 and 2014.”
The US Justice Department last year described the affair as an example of “economic warfare” and alleged that Renopharma, based in the city of Nankin, was “financed by the Chinese government.”