West Coast Editor

In a move that could markedly quicken the approval pace for its snail-based synthetic pain drug, Prialt, Elan Corp. plc added encouraging Phase III data to the new drug application and expects a review time of about six months.

The news came one day after Dublin, Ireland-based Elan disclosed that its other late-stage product candidate, Antegren (natalizumab), for multiple sclerosis, won fast-track designation from the FDA. Antegren, co-developed with Biogen Idec Inc., of Cambridge, Mass., also targets Crohn's disease.

Elan's stock (NYSE:ELN) closed Tuesday at $24.38, down 2 cents, having jumped 43 cents on Monday's Antegren news, which "kind of overshadowed" the more recent Prialt disclosure, noted Deborah Knobelman, a specialty pharmaceutical analyst with ThinkEquity Partners in New York.

The Prialt news does contribute to Elan's positive news flow, though, and might be regarded as a good sign by investors.

"This drug has been back and forth with the FDA for several years," Knobelman pointed out, and making progress with the agency "shows the new management team has their act together." Elan has been steadily transforming itself from a pharmaceutical company to a biotechnology firm. (See BioWorld Today, June 18, 2004.)

Anita Kawatra, global spokeswoman for Elan, told BioWorld Today the company will not disclose results from the latest Phase III trial until the FDA has reviewed them, but Elan assured investors that the study yielded "statistically significant benefits at lower doses and a slower titration schedule" than had been tried in previous experiments.

"We will be presenting that data at a medical meeting in the appropriate forum," Kawatra said, declining to say how soon that might happen.

Prialt is the first in a class of non-opioid analgesics known as N-type calcium channel blockers, given directly into the fluid surrounding the spinal cord by way of a surgically implanted catheter.

"The route of administration is pretty much what is going to make it a niche product," she told BioWorld Today. "I think it will probably be the thought leaders in the pain market who will feel more comfortable prescribing a product like this. And you really need to keep a close watch on the dosing."

The synthetic equivalent of a naturally occurring conopeptide found in a marine snail known as Conus magus, Prialt selectively blocks calcium channels on nerves that ordinarily transmit pain signals to the brain.

"It's a different approach," Knobelman said.

Though Antegren is considered the investment driver for Elan, Kawatra said Prialt might prove strong, too - eventually.

"We've said it has a potential future market of 300,000 people, but that's really going into five years," she said. "It's going to start out at a much lower number." Knobelman estimated Prialt sales would top out at $150 million.

Meanwhile, Antegren is the subject of a filing for MS in the U.S. and for Crohn's disease in Europe. The Crohn's indication seemed unlikely to gain approval in the States because an induction trial failed to hit statistical significance at its primary endpoint, Knobelman said.

"You need induction and maintenance [studies] for the drug to be accepted by the marketplace," she added. Another trial is under way, "but I think they're going to talk to the FDA in the next couple of weeks to determine their filing strategy." Positive subset results from the earlier trial, if stratified for the agency, might be enough to get the approval process rolling, she said.

More positive news flow could come later in July, when Elan is expected to disclose data from an Alzheimer's disease trial with the ill-fated AN-1792, which fizzled in 2002 when a Phase IIa trial was stopped.

"It's never going to come to the marketplace because it has an encephalitis side effect," Knobelman said, but Elan has another drug with a similar mechanism of action that seems promising.

"We don't know for sure, but it's an antibody to beta-amyloid vs. the amyloid itself," she said. In the Phase IIa trial, Elan vaccinated some 360 mild to moderate AD patients with the human 42-amino-acid A-beta peptide, and 15 of the patients developed severe side effects. (See BioWorld Today, March 12, 2003.)

AN-1792 is partnered with Wyeth-Ayerst Laboratories, the pharmaceutical division of Madison, N.J.-based American Home Products Corp., which now is Wyeth. Findings from Elan's AD program are slated to be presented at the International Conference on Alzheimer's Disease and Related Disorders, presented by the Alzheimer's Association in Philadelphia.

Separate from the Prialt news, Elan disclosed Tuesday the repayment by Elan Pharmaceutical Investments II Ltd. (EPIL II) of the $450 million in guaranteed notes issued June 28, 2000, and matured on June 28, together with accrued interest for the period from Dec. 31 to June 28 of $21.5 million.

Of the aggregate payment of $471.5 million, $79.7 million was funded from the cash resources in EPIL II and the sale of EPIL II's entire investment portfolio, Elan said, with the balance of $391.8 million funded by Elan under its guarantee. Elan will show a charge in this year's second quarter of $33.4 million, consisting of interest of $10.8 million and investment losses of $22.6 million.

After the payment, Elan's cash balance exceeds $670 million, and its debt position has been cut to about $1.5 billion, roughly $1.1 billion of which is not due until 2008, the company said.