HutchMed (China), controlled by billionaire Li Ka-shing, plunged in Hong Kong after the pharmaceutical group failed to win approval in the US for its pancreatic cancer treatment drug. The stock sank as much as 19.2 per cent in intraday trading before closing 17.7 per cent lower at HK$21.15 in the biggest drop since its listing in June last year. The rout erased almost US$500 million from its market value. Tuesday’s decline brought the losses to 72.7 per cent from its all-time high closing price of HK$77.60 in July. The US Food and Drug Administration declined to approve its drug known as Surufatinib for the treatment of pancreatic and extrapancreatic neuroendocrine tumours, it said in an exchange filing late on Monday. The FDA said the current data package, based on two positive Phase ІІІ trials in China and one bridging study in the US, does not support an approval at this time, according to the filing. A multi-regional clinical trial, which includes subjects more representative of the US patient population and medical practices, is required for US approval, it added. The rejection is the second involving a Chinese drug producer this year. An FDA advisory committee decided in February to ask Innovent Biologics and its US partner Eli Lilly to broaden the clinical trials for its cancer drugs, raising concerns that Chinese biotechnology players could be the next source of friction in US-China relations. HutchMed, which develops targeted therapies and immunotherapies for treating cancer and immunological diseases, counts Li’s flagship company CK Hutchison as its biggest shareholder with a 38.5 per cent stake, according to its annual report. HutchMed said in the announcement that it is working with the FDA to evaluate its next steps. The firm will continue to engage with the FDA to bring Surufatinib to patients in the US, said Su Weiguo, its chief executive and chief scientific officer. The company remains confident about the clinical value of the drug, he added. Surufatinib was approved in China for the treatment of pancreatic and extra-pancreatic tumours in June 2021 and December 2020, respectively, according to previous company statements.