Shares in Medeva, the UK drug group that makes the Ionamin anti-obesity drug fell 14p to 248p and British Biotech's shares slumped to 173p at one point before closing 15.5p down at 185.5p.
British Biotech said that it was expanding clinical trials on its lead Zacutex product, a treatment for pancreatitis which would delay approval of the drug in the US by 12 to 18 months.
Some analysts at British Biotech's annual results meeting were also disappointed that data from crucial Phase III trial data on Marimastat, British Bio's big-hope cancer drug, would not be released until early 1999. Several had expected the results at the end of next year.
However, Mark Brewer, analyst at Hoare Govett said expectations that the group would file clinical data from Marimastat next year were "misplaced". Keith McCullagh, British Biotech's chief executive, said he had indicated the filing date at the group's last results.
"There is no delay and the Marimastat trials are going extremely well." The company is starting two new Marimastat trials in lung and ovarian cancer, taking its total to six trials in a variety of serious cancers. "We are testing this drug in the severest tumour types", Mr McCullagh said.
The expansion of the Zacutex trials from 450 to 1,500 patients was based on data from the UK which showed that Zacutex increased survival rates. The new trials would include a measure of mortality as well as original measures like organ failure rates. Though the expansion would delay approval in the US, Mr McCullagh said it was positive longer term. "We are changing the end point of the trial to a more powerful one. We will now compare Zacutex and a placebo on survival rates. If we are able to prove that it saves lives we will get rapid approval by the FDA [US drug regulator]. If we can claim this drug saves lives we can ask a much better price. It is good for shareholders in the long term."
The news had no impact on European approval of Zacutex, expected in around a year.
Separately, Medeva yesterday was playing down a "dear doctor" letter sent by the FDA, warning doctors in the US that heart valve problems were associated with patients taking the anti-obesity drug fen-phem made by American Home Products.
Medeva, which makes the drug under the brand name Ionamin, said its product was recommended only for short-term treatment, but that the heart problems occurred in patients taking the drug for over a year and related to only 24 patients. But the group added that it was talking to the FDA about the wording on its packaging.Reuse content