The Food and Drug Administration has refused to approve two cancer treatments developed by Chinese drugmakers, citing trial design in one rejection and manufacturing issues in the other.
Hong Kong-based Hutchmed announced Monday the FDA asked it to complete a "multi-region" trial in pancreatic and extra-pancreatic neuroendocrine tumors before the agency will approve surufatinib. The company had completed two Phase 3 trials in China, as well as a "bridging" trial in the U.S. in an effort to prove the drug would be similarly effective in U.S. patients.
Separately, Shanghai-based Junshi Biosciences, along with U.S. partner Coherus, announced their cancer immunotherapy called toripalimab was rejected as a throat cancer treatment because of a manufacturing change the two companies claim is "readily addressable."
The FDA's decisions on Hutchmed's and Junshi's drugs follow a March rejection for a cancer treatment developed by China-based Innovent Biologics, which was only tested in Chinese patients. FDA officials have in recent months made clear they expect cancer drugs to be evaluated across diverse patient populations and, ideally, run in multiple countries. That stance has seemingly closed the door to a slate of medicines tested exclusively or primarily in China.
The rejections, along with a clinical hold on a closely watched Vertex Pharmaceuticals drug for diabetes also announced Monday, add to a string of negative news for the biotech sector, which in April recorded its worst monthly stock market performance in years.
In the FDA's letter to Hutchmed, the regulator said additional trials would need to include patients more representative of people in the U.S. who have neuroendocrine tumors, as well as comparing surufatinib to the standard of care in the U.S.
Patients in the China trials had to have progressed following two lines of treatment that included hormonal therapy or chemotherapy. In the U.S., guidelines recommend some patients can receive the immunotherapy combination Opdivo and Yervoy after chemotherapy, meaning Hutchmed's trial results might not be the same if U.S. patients were studied.
The FDA also indicated that issues over "inspection scheduling and access" related to the COVID-19 pandemic contributed to the rejection, Hutchmed said.
The two completed Phase 3 trials of surufatinib — in neuroendocrine tumors in the pancreas and outside the organ — began in late 2015 and delivered results in 2020. Surufatinib has been approved for use as Sulanda in China, where it earned nearly $12 million in 2021.
U.S.-listed shares in Hutchmed fell by 18% in morning trading Monday.
The rejection of Junshi and Coherus' toripalimab, meanwhile, was due to a change to the drug's quality control process that the FDA requested. The two companies said they expect to be able to complete the changes by mid-summer. Travel-related restrictions due to the COVID-19 pandemic will hinder on-site inspections, however, extending the agency's subsequent review to six months, the companies said.
Toripalimab blocks a protein called PD-1, similar to how Merck & Co.'s Keytruda and Bristol Myers Squibb's Opdivo work. If approved, it would have been the eighth drug of its type cleared in the U.S. The type of cancer it targets, nasopharyngeal carcinoma, is a relatively rare disease that neither of the two market-leading PD-1s has been approved to treat.
Like surufatinib, toripalimab is approved in China, where it is marketed as Tuoyi.