Updated from 10:45 a.m. EST
plummeted Monday after the company announced another regulatory delay for its bowel-disorders drug.
Adolor, which has a development and marketing deal with
, said the Food and Drug Administration wants more safety data about the drug Entereg.
The drug is targeted at post-operative ileus, or POI, a side effect sometimes seen among surgical patients who receive powerful painkillers like morphine. POI causes abdominal pain, nausea, vomiting and constipation. The companies say there are no other drugs approved by the FDA to treat the condition.
Adolor's stock fell $6.14, or 44%, to $7.80. The stock dropped as low as $7.63, its worst level of the past year. At the halfway point of the session, trading volume was 16 times heavier than normal.
GlaxoSmithKline was able to absorb the setback, and its stock was up 31 cents to $53.61.
The FDA granted conditional approval for Entereg, but it won't make a final ruling until the companies complete an ongoing clinical trial and submit a risk-management plan to the regulatory agency. The FDA wants to see 12 months of safety data, including information about cardiovascular risks.
Adolor has no products on the market. Entereg is its lead compound.
The companies expect to receive results during the second quarter of 2007 from a clinical trial for POI patients experiencing chronic non-cancer pain.
Their application to the FDA contained an interim analysis for six months of safety data, which showed a statistically insignificant increase in "serious cardiovascular" side effects for Entereg patients compared with those receiving a placebo.
"The reported events were in patients at high risk for cardiovascular disease, did not appear to be linked to duration of dosing and were consistent with epidemiological expectations for the subject population," the companies said. "Combined results from all completed studies in the chronic population submitted by GlaxoSmithKline to the FDA did not support a conclusion that patients taking
Entereg were at increased risk for serious cardiovascular events."
David Madden, interim president and CEO of Adolor, said the companies will meet with the FDA to provide the additional data as quickly as possible.
Monday's announcement marks the second time Adolor and GlaxoSmithKline have received conditional approvals from the FDA for Entereg. The FDA's first notice came in July 2005, when the agency asked for more proof that the drug was effective in patients undergoing bowel surgery. The companies filed a response in May 2006.
Adolor investors should be getting accumstomed to a roller-coaster ride.
In February, Adolor reported
favorable clinical-trial results for Entereg, and the stock soared.
But in September, the shares sunk after the companies reported disappointing test results.
"We continue to believe that Entereg has significant potential to benefit patients at risk of developing POI ... and remain committed to its continued development," said Yvonne Greenstreet, senior vice president for research and development at GlaxoSmithKline.