Merck Ends Testing of Substance P Depression Drug
Whitehouse Station, New Jersey, Jan. 22 (Bloomberg) -- Merck & Co., the world's biggest drugmaker, said it halted tests of an experimental antidepressant that had been considered one of Merck's best hedges against a wave of patent losses by 2001.
Merck fell 7 5/16 to 139 in late trading after announcing the end of testing for MK-869 drug against depression. Early studies didn't provide enough evidence the drug works as an anti- depressant. Instead, Merck will continue testing it for use in nausea in cancer patients.
The drug, which worked on a brain chemical known as substance P, was seen as one of Merck's best prospects for offsetting the loss of patents by 2001 on four drugs with more than $5 billion in combined annual sales. These drugs include Vasotec with more than $2 billion in annual sales.
''It's a major setback for Merck,'' said Mike Krensavage, an analyst with Brown Brothers Harriman, who has a short-term ''neutral'' rating on Merck. ''The insurance policy they were going to use against the patent exposures has been canceled.''
Now, Merck must look to one drug alone, its experimental painkiller Vioxx, Krensavage said. Vioxx, which is waiting for U.S. approval, is part of a new class of drug that appear to treat pain and inflammation without irritating the stomach as does aspirin and other painkillers.
Rival Monsanto Co. last month won U.S. Food and Drug Administration approval of a similar drug, Celebrex. It intends to introduce the drug in late February, although doctors already are writing prescriptions for it.
Relying on Vioxx
''Without MK-869, Merck will have to rely even more on Vioxx and it's not good,'' to depend so much on one product, Krensavage said.
In a release, the company said phase II trials of the compound ''suggest'' it has anti-depressant activity, but that the drug's effect was not significantly better than the effect seen with a placebo sugar pill.
Merck's earlier studies had led investors and analysts to speculate the drug might someday rival some of the world's top- selling drugs, such as SmithKline Beecham Plc's Paxil. Depression drugs are among the world's top-sellers. Eli Lilly & Co.'s Prozac has annual sales of more than $2 billion.
''It's not good news, to say the least,'' said Hemant Shah, an independent pharmaceutical analyst. ''This was regarded by many analysts as the next big multibillion-dollar drug, mostly because of its depression use,'' he said.
Merck began building expectations for MK-869 in December 1997, taking the unusual step of highlighting early research about the compound at its analyst meeting. Merck touted its experimental drug ''as better than Prozac,'' Shah said.
Merck said today in a release that as it pursues development of MK-869 for nausea, it will continue early trials of a different, more potent compound that has shown promise in treating depression.
A study published this week in the prestigious New England Journal of Medicine found MK-869 to be effective at neutralizing the waves of nausea and vomiting that most often strike cancer patients as they are undergoing chemotherapy.
|
