Shares in Indevus Pharmaceuticals have been battered by the news that US regulators have turned down its bid to get the bladder cancer treatment Valstar back on the market.

Indevus said that it has received a non-approvable letter from the US Food and Drug Administration for Valstar (valrubicin) because a recent inspection by the agency of the firm’s third-party manufacturing facility for the therapy unveiled problems. The company said it believes that “successfully addressing the deficiencies at the manufacturing plant is the only remaining item for product approval”, which it expects to occur in the next few months.

Valstar was withdrawn from the market in 2002 due to impurities in the original formulation but Indevus said that those particular issues have since been resolved. Chief executive Glenn Cooper noted that the firm has been in “direct communication with the FDA” so that the manufacturing problem can be resolved “in an expeditious manner”. He added that agency staff “appreciate the need and desire to return Valstar, currently on the FDA Drug Shortages List, to the market as quickly as possible”.