Washington Editor
Study results showed that Acorda Therapeutics Inc.'s multiple sclerosis drug Fampridine-SR does not increase a patient's risk of developing cardiac arrhythmias, or an irregular heart beat.
News of the positive results sent shares of Hawthorne, N.Y.-based Acorda (NASDAQ:ACOR) up 25.3 percent Monday, or $5.50, to close at $27.28.
Fampridine-SR, a sustained-release tablet form 4-aminopyridine, which blocks exposed potassium channels to improve electrical signaling in demyelinated neurons, currently is in Phase III development as an agent to improve the walking ability of patients with multiple sclerosis.
Because increases in the QT interval - a measure of the time between the start of the Q wave and the end of the T wave in the heart's electrical cycle - may indicate an increased risk of developing cardiac arrhythmias, the FDA requires so-called thorough QT studies for all new drugs seeking marketing approval, noted CEO Ron Cohen.
The double-blind QT trial compared the electrocardiographic effects of 10-mg or 30-mg Fampridine-SR with placebo and moxifloxacin in 208 healthy participants.
Moxifloxacin was used as a positive control in the study because it is known to increase the QT interval, Cohen said Monday during a conference call.
The placebo-corrected QTc mean change from baseline was 0 ms for 10-mg Fampridine-SR and 1 ms for the 30-mg dose, while it was slightly more than 5 ms for moxifloxacin, he told investors and analysts.
No participants in the Fampridine-SR cohort showed increases in the QTci - the QT interval as corrected for individual heart rate - of greater than 30 ms, nor did any of the Fampridine-SR participants display a QTci interval that exceeded 480 ms at any time, the company said.
Adverse events for Fampridine-SR in the study were consistent with "what we have seen in previous clinical trials," Cohen maintained. However, he noted that there was a single serious adverse event involving an episode of visual hallucination in a study participant who had received the 30-mg, or "supratherapeutic," twice-daily dose.
"This resolved quickly and did not recur," Cohen asserted. No participants experienced seizures in the study, he added.
The thorough QT study, Cohen said, was the "final requirement in respect to QT that the FDA requested of us" as far as the firm is aware.
The company has ongoing EKG monitoring in three Fampridine-SR extension studies, he said. However, Cohen noted, "that is not really specifically QT monitoring. It's just overall safety monitoring."
Andrew R. Blight, Acorda's chief scientific officer, noted that the firm's safety database shows that at least 1,500 patients have been exposed to Fampridine-SR, with about 300 patients receiving the drug for one year.
Senior Biotechnology Analyst Elemer Piros of Rodman & Renshaw Equity Research said that based on the positive results of the QT study, he did not expect the FDA to ask for further clinical evaluation of Fampridine-SR on the QT interval.
Acorda recently completed enrollment of 240 patients at 39 clinical trial sites in the U.S. and Canada in the firm's second Phase III trial of Fampridine-SR.
The firm expects to have results from that study in the second quarter of 2008, Cohen said.
Results of the firm's first Phase III trial released in September 2006 showed that 34.8 percent of patients taking Fampridine-SR improved their walking speed compared with 8.3 percent of those taking placebo. The average increase in walking speed over the treatment period compared with baseline was 25.2 percent for the drug group vs. 4.7 percent for the placebo group. (See BioWorld Today, Sept. 26, 2006.)
Analyst Phil Nadeau of Cowen & Co. said that based on the strong results of the first Fampridine-SR Phase III trial, he expected results of the second Phase III study to "also be successful."
"We think over the next six months Fampridine will emerge as one of the most interesting product launches in 2009-10 in small-cap biotech, and that this will drive increasing interest in shares of Acorda," Nadeau said in a research note. He said he anticipated Acorda to outperform the market by more than 40 percent over the next year as Fampridine-SR completes its second Phase III trial.