West Coast Editor
With its own product for multiple sclerosis and spinal cord injuries already in the works, Acorda Therapeutics Inc. acquired from Elan Corp. plc all U.S. rights to oral Zanaflex (tizanidine), a marketed treatment for spasticity in patients with those conditions.
Financial terms were not disclosed, but Acorda gets sales, marketing and distribution rights in the U.S. to the Zanaflex tablet, as well as to a new capsule formulation already approved by the FDA. Elan will supply Acorda with the capsule, for which Elan keeps manufacturing rights.
"The essence here is the capsule we're going to be launching, hopefully at the beginning of 2005," said Ron Cohen, president and CEO of Hawthorne, N.Y.-based Acorda.
Exactly how valuable the drug might be is difficult to determine, acknowledged Tierney Saccavino, Acorda's director of corporate communications.
"Elan has not publicly disclosed what the sales revenues are" for Zanaflex, she said. "It's a pretty small product for them, and they tend to report aggregate numbers. We do know [sales numbers], but since the product was theirs then, we're not going to disclose what they haven't disclosed."
Privately held Acorda is not discussing sales forecasts either, she said.
Zanaflex is believed to work by the pre-synaptic inhibition of motor neurons so that spasticity is reduced without affecting muscle function. The tablet is available in 2-mg and 4-mg strengths, and the capsule, which Acorda plans to launch early next year, will be sold in 2-mg, 4-mg and 6-mg strengths.
Because the capsule has a different pharmacokinetic profile than the tablet when taken with food, it might even be opened and sprinkled into liquids or soft food (aside from already being easier to swallow than tablets for some patients). What's more, the 6-mg version might allow taking fewer pills per day.
Both factors might allow physicians more flexibility in prescribing remedies for spasticity.
"People are taking a lot of pills a day, and people generally don't like to take pills," Cohen said. "When I was practicing internal medicine, the biggest issue day to day was that I never knew if patients were going to take medicines as prescribed. That's half the battle."
The most frequent adverse events reported by patients were dry mouth, sedation, asthenia and dizziness, and such side effects most often were considered mild to moderate. Dry mouth "we believe is related to the local effect of the pill in the mouth, which may be mitigated by the capsule," Cohen told BioWorld Today, but cautioned that he was not making that as a claim.
Acorda's other drug for MS and SCI - also being developed under a license from Elan - is Fampridine-SR, an oral, sustained-release formulation of fampridine, which blocks exposed potassium channels in damaged nerve fibers that have lost their insulating sheath of myelin, thereby allowing the fibers to transmit impulses again. The drug is dosed twice daily.
In April, Fampridine-SR missed its endpoints (including reduction of spasticity and improvement of patients' Subject Global Impression rating) in two pivotal Phase III trials in SCI, but showed positive trends in a Phase II MS trial. Acorda said it would pursue the MS indication, conducting either another Phase II trial or a Phase III trial, depending on the FDA's preference. (See BioWorld Today, April 15, 2004.)
The Phase III SCI program, Saccavino said, is "on hold right now, although we continue to believe there is a genuine clinical and physiological benefit there, so we're not giving up" on it. In MS, Acorda and the FDA are "designing what the next studies will look like."
In October, Acorda's deal with Elan for Fampridine-SR was expanded, with Acorda gaining exclusive, worldwide rights to the product. Under the terms, Acorda is responsible for clinical development, registration and potential commercialization, while Elan would be responsible for formulation development and manufacturing.
Up to 75 percent of people with chronic SCI, and the majority of MS patients, experience some form of spasticity, which has been estimated to affect more than a half a million people in the U.S., and more than 12 million worldwide.
Even before Acorda became interested in acquiring rights to Zanaflex, "we got good feedback on it from people" during advisory sessions with physicians treating SCI patients, Saccavino told BioWorld Today, adding that the drug could be used with Fampridine-SR.
"We have not seen decreased effectiveness if people are taking existing medications," she said. Cohen added that "you're in a marketplace where people routinely take more than one medication or switch from one to the other."
What about generic competition for Zanaflex? Spring Valley, N.Y.-based Pharmaceutical Resources Inc., which sells a generic version of tizanidine through its subsidiary Par Pharmaceuticals Inc., in its most recent earnings report noted a first-quarter drop in sales due to the entry of other generics.
Cohen said Zanaflex is "subject to what I would say is the usual competition" from generics.
He noted that the new capsule, because it's a separate FDA approval, would not be substitutable for generics by pharmacists.
"We believe we will generate revenues and income from this, but I would say at least as important is the strategic view," Cohen said, noting that "there are not a whole lot of commercial products we would be in the running for or be able to afford" and Zanaflex is "directly in our sweet spot."