Acorda’s MS Drug May Need More Study

Acorda Therapeutics Inc.’s famprdine- SR, the first pill to improve walking in multiple sclerosis patients, may not be “clinically meaningful,” U.S. regulators said. The shares fell the most ever in Nasdaq trading.

Food and Drug Administration reviewers said they had doubts about the trial design for the drug, fampridine-SR, in a report posted today on the agency’s Web site. An FDA advisory panel will meet Oct. 14 in Adelphi, Maryland, to discuss whether the drug works well enough to justify an increased risk of seizures.

Fampridine, designed to restore nerve signals, was tested in 25-foot timed walks, a novel way to measure effectiveness. Older drugs are injected to reduce relapses and slow progression of the disease. MS damages the brain and spinal cord, affecting mobility, according to the National Institutes of Health.

The improvement patients saw with fampridine “was numerically quite small, and the average time to complete the 25-foot walk was not different between the treatment groups in either study,” said Eric Bastings, deputy director of the FDA’s Division of Neurology Products, in a memo to the panel. “For these reasons, it appears that the clinical meaning of the differences seen on the primary outcomes is in question.”

Shares Fall

Acorda, of Hawthorne, New York, dropped $4.76, or 21 percent, to $17.52 at 4 p.m. New York time in Nasdaq Stock Market composite trading. It was the biggest percentage decline since the drugmaker’s initial public offering in February 2006.

“Fampridine’s panel on Wednesday is going to be somewhat more contentious than we had anticipated,” said Phil Nadeau, a Cowen & Co. analyst in New York, in a note to clients today. “It would seem from the documents that the FDA may be moving the goal posts on Acorda” with new hurdles for proving the drug works, he said.

Acorda spokesman Jeff Macdonald declined to comment on the FDA report in a telephone interview today. The company will comment after the Oct. 14 FDA panel meeting, he said.

“How relevant is walking speed to MS?” said Mike King, an analyst for Merriman Curhan Ford & Co., in a telephone interview. “It’s risk versus benefit for the FDA, and this is a small benefit in a minority of patients, and a real risk of seizure. How do you balance those questions?”

Acorda is racing European drugmakers Merck KGaA and Novartis AG to introduce the first pill for MS. Current treatments, led by Teva Pharmaceutical Industries Ltd.’s Copaxone and Biogen Idec Inc.’s Avonex, are shots that reduce relapses and prevent symptoms of the disease from getting worse.

Damage to Myelin

MS strikes more than 2.5 million people worldwide and is caused by damage to myelin, the protective sheath around nerve cells in the brain and spinal cord, according to the National Multiple Sclerosis Society. MS worsens as damage to myelin causes muscle weakness, trouble with coordination and critical thinking, and memory loss. Women are at least twice as likely as men to get the disease.

“There might be someone using a walker or cane who finds it difficult to get from the kitchen to the bedroom, and fampridine could make it easier,” said Howard Weiner, director of the Partners Multiple Sclerosis Center at Brigham & Women’s Hospital in Boston, in a phone interview before the FDA documents were released.

A timed walking test is a logical way to measure the effectiveness of fampridine because there is a “physiologic” connection between the walking ability and the progression of the disease, Weiner said.

Priority Review

The FDA said on May 6 it would review fampridine under an expedited “priority review” program to speed clearance of novel medicines for serious illnesses. A drug awarded priority review is supposed to be decided on within six months, four months quicker than the review process for most medicines. Acorda in May said it anticipated an approval decision from the agency by Oct. 22.

Ron Cohen, Acorda’s founder and chief executive officer, said he didn’t ask for a quick review of fampridine. Transparency is critical for investors in the unprofitable biotech company, and Cohen said he was worried the application might get held up if it was taken out of normal review channels.

“To the extent that there are delays, or there are uncertainties in the process, that’s not a good thing because the last thing an investor wants to see is uncertainty,” Cohen said in an Aug. 18 phone interview.

Decades of Development

Development of fampridine was started by Dublin-based Elan Corp. in the 1990s and later licensed by Acorda. The drug is a sustained-release form of 4-aminopyridine, which some MS patients now get from compounding pharmacies with a doctor’s prescription. These medicines are custom made for patients and overdoses can cause seizures and other side effects.

Fampridine helped 35 percent of MS patients walk faster in a study whose results were reported in February. The drug’s ability to restore nerve signals after myelin is lost suggests it may also reduce other symptoms of the disease, regardless of what other medicines patients are taking, said John Richert, executive vice president of research and clinical programs for the New York-based National Multiple Sclerosis Society.

“Potentially, it could be tried in the large majority of people with MS,” Richert said in an Oct. 7 phone interview. “It has at least the theoretic potential for being able to help with virtually any MS symptom.”

Elan will manufacture fampridine if it is approved and receive royalties on sales. The drug is the first that Acorda has submitted to the FDA. The company also sells Zanaflex capsules, a treatment for spastic muscles that it acquired from Elan in 2004.

Biogen Partnership

Cambridge, Massachusetts-based Biogen agreed in July to pay as much as $510 million for rights to market fampridine outside the U.S. after Acorda said it wouldn’t be able to operate beyond next year without a partner. Naomi Aoki, a spokeswoman for Biogen, didn’t immediately return a call seeking comment.

German drugmaker Merck asked the FDA last month to approve cladribine tablets to reduce relapses of MS. Novartis, of Basel, Switzerland, plans to submit its experimental pill, FTY720, to U.S. regulators by the end of the year to reduce relapse and progression of disability. Paris-based Sanofi-Aventis SA is also in late stages of testing its teriflunomide pill for MS.

“Patients tell us they’re desperate for an oral drug,” Richert, of the MS Society, said. “We know that some people don’t go on medication in the first place because they can’t stand the thought of injection.”