GSK Plc shares tumbled after its blood cancer drug failed to secure the backing of a panel of US regulatory advisers, putting its approval in doubt.

The British pharmaceutical company said combinations for its Blenrep drug were evaluated in adults with relapsed or refractory multiple myeloma who have previously received at least one line of therapy.

The British drugmaker was trying to revive the drug, which was pulled from U.S. markets in 2022 after failing a late-stage study. GSK's renewed application is based on two late-stage trials showing that Blenrep, when used in combination, improved overall survival in patients.