UPDATE 2-Wyeth, Progenics bowel drug wins US approval
(Adds company, FDA comments, background)
WASHINGTON, April 24 (Reuters) - Wyeth WYE.N and Progenics Pharmaceuticals Inc (PGNX.O) won U.S. approval to sell a new drug to relieve the constipation that often occurs with use of morphine or other opioid painkillers, regulators said on Thursday.
The prescription drug, Relistor, is the first medicine approved to treat opioid-induced constipation.
The Food and Drug Administration approved the drug to help restore bowel function in patients with advanced illness who are receiving opioids continuously to help relieve pain.
The approved version of the drug is given by injection under the skin. Oral and intravenous forms are under development, and the companies are studying other uses.
The drug, cleared by Canada in March, is the first approved product for Progenics, which saw its shares rise nearly 33 percent to close at $10.64 on Thursday as Relistor received a positive opinion from a European committee.
Progenics shares then jumped to $12.23 in extended trade in response to the FDA approval.
Wyeth has forecast that peak sales for the franchise could eventually top $1 billion annually.
Relistor was dealt a blow in March, however, when the companies announced that tests of an intravenous form failed in to improve bowel function in a late-stage trial for another bowel condition called post-operative ileus. More research for that use is ongoing.
Regarding the approved use, Wyeth and Progenics said more than 1.5 million Americans annually receive palliative care because of a serious illness such as incurable cancer, AIDS, or advanced lung disease.
Many of those patients are treated with opioids to manage pain. Constipation is a common side effect of opioids, and laxatives provide limited relief, company officials said.
Relistor was designed to block the effects of opioids in the gut without interfering with pain relief.
The FDA said the drug was shown to be safe and effective in two company studies of 287 people with a median age of 68. All patients had a life expectancy of less than six months.
In one study, 62 percent had a bowel movement within four hours of their first Relistor dose, compared with 14 percent who got a placebo, Wyeth said.
The effectiveness of a second study was 48 percent for Relistor patients and 16 percent for the placebo group.
Relistor did not disrupt the pain-relieving effects of opioids, the drugmakers said.
Common side effects included abdominal pain, gas, nausea, dizziness and diarrhea, the FDA said. The drug is not recommended for patients with known or suspected bowel obstructions.
GlaxoSmithKline Plc (GSK.L) and Adolor Corp (ADLR.O) are developing a similar drug called Entereg for post-operative ileus. An FDA ruling on that drug is expected by May. (Reporting by Lisa Richwine; editing by Carol Bishopric and Braden Reddall)
