Endo Pharmaceuticals Holdings Inc. said the second of three Phase III trials of MorphiDex did not meet its primary or secondary endpoints, thus throwing serious doubt over the company's ability to submit a successful supplement to the new drug application on file with the FDA.

Endo's stock (NASDAQ:ENDP) dropped $2.68 on the news Monday, or 28.2 percent, to close at $6.82.

In the trial, MorphiDex (morphine and the N-methyl-D-aspartate-receptor antagonist) was compared to immediate-release morphine sulfate in 327 chronic pain patients. The trial was designed to demonstrate analgesic superiority of MorphiDex over morphine alone for patients with moderate to severe chronic pain as measured by the change in the level of pain reported by patients. The secondary endpoint was whether MorphiDex would reduce the rate of opioid analgesic tolerance.

"We are disappointed that the study, similar to our previously announced Phase III MorphiDex trial, did not have a positive outcome," said Carol Ammon, Endo's chairman and CEO. "While we expect the results of the remaining Phase III trial to be available shortly, we believe the data generated today suggest that we will not have enough evidence to support a filing of an amendment to the MorphiDex [new drug application]."

MorphiDex's history extends back to a company called Algos Pharmaceutical Corp. In August 1998, Algos filed a new drug application with the FDA for MorphiDex and a year later received a not-approvable letter. At the time, the company said it was "absolutely committed to working with the FDA to get [MorphiDex] to the American people," but its stock lost 59 percent of its value the day the news was released. (See BioWorld Today, Aug. 4, 1999.)

However, in November 1999, Algos and Endo agreed to a stock merger that created a $1.1 billion company focused on pain management. The move made Endo a public company, and it has controlled MorphiDex since. (See BioWorld Today, Nov. 30, 1999.)

Endo, however, has not decided what to do with it. Bill Newbould, vice president of corporate communications at Endo, told BioWorld Today the third Phase III trial is fully enrolled and the company is expecting data by the end of the year. With two of the three trials completed and negative, a supplemental filing appears unlikely in the near future, but Newbould said Endo hasn't "ruled out further studies on that Dex platform or MorphiDex itself," saying the company needed "to look at the data and see what it means."

But if you widen the lens, the impact of MorphiDex shrinks anyway, he said.

"When you look at the overall bigger picture, it's certainly not the end of the world," he said. "We have a lot of other things going on. We aren't relying on MorphiDex for our future growth."

The growth responsibility has been falling to Endo's marketed products, Percocet and Lidoderm. Net sales of Percocet were $36.6 million for the third quarter, up 123 percent from 2001's third quarter. For the first nine months, the product pulled in $100.7 million, up from $72.8 million in 2001.

Lidoderm grew from $16.3 million in the third quarter of 2001 to $24.1 million in the quarter ended Sept. 30. And the company has had net sales overall of $285.5 million in the first nine months of the year, increased from $173.5 million the year before. Excluding certain charges, the company has a net income of $17.1 million for the first three quarters, or 19 cents per diluted share. It had $36.5 million in cash and cash equivalents as of Sept. 30.

The increasing sales prompted Endo to raise its guidance for the third time this year - it now anticipates $380 million in net sales for the year, up from $350 million.

In July, Endo, of Chadds Ford, Pa., said its wholly owned subsidiary, Endo Pharmaceuticals Inc., acquired BML Pharmaceuticals Inc., of Manhasset, N.Y., for an up-front payment of $14 million. BML operates as a wholly owned subsidiary of Endo Pharmaceuticals Inc. The move gave Endo Immunol, an oral rinse in Phase III trials for oral mucositis.