WuXi AppTec, WuXi Bio Tumble After US Panel Advances Ban Bill

WuXi AppTec Co. tumbled after a US Senate committee advanced a bill that may ban Chinese biotech firms from accessing federal contracts and largely cut off the biopharmaceutical company from the market that generates more than half of its revenue.

Shares of WuXi AppTec plunged as much as 24%, while its sister company WuXi Biologics Cayman Inc., which is also named in the bill, dropped 23%. Both stocks have lost more than 40% so far this year, making them the worst performers on the benchmark Hang Seng Index.

The legislation adds to the geopolitical risk faced ...