Isis Pharmaceuticals, Inc. (NASDAQ: ISIS) today provided an update on its ongoing open label, multiple dose Phase 2 study of ISIS-SMNRx in infants with spinal muscular atrophy (SMA). To date, all four infants in the 6 mg cohort have been in the study for over six months and are now approximately nine and a half to 16 months in age with an average age of approximately 12 and a half months. All four infants are alive and none have required permanent respiratory assistance.
"We are pleased with the tolerability we have observed with ISIS-SMNRx to date. This is the first study to investigate ISIS-SMNRx in infants with SMA. Even though these are interim results from a small number of infants, we are encouraged by the observation that all four infants in the 6 mg cohort are still alive and not on permanent ventilation. These interim results, while early, provide support for advancing ISIS-SMNRx into a Phase 3 study in infants," said C. Frank Bennett, Ph.D., senior vice president of research. "We look forward to the longer-term results from this ongoing study and plan to report more detailed data at the upcoming American Academy of Neurology meeting in April."
In the ongoing Phase 2 study, doses of either 6 mg or 12 mg are administered intrathecally on Days 1, 15 and 85. All infants from the 6 mg dose cohort have completed the three initially scheduled doses and are now eligible to receive a maintenance dose of 12 mg six months after their initial three scheduled doses. In the 12 mg cohort, 10 infants have received at least one dose of ISIS-SMNRx to date. Of these 10 infants, nine still remain in the study. One infant in the 12 mg cohort succumbed to pneumonia early in the treatment portion of study. In both cohorts, ISIS-SMNRx has been well tolerated.
"Infants with type 1 SMA have the most severe form of this disease. It is tragic that, because of the severity of their disease, about half of these patients won't make it to their first birthday and most won't make it to their second birthday," said Dr. Tom Crawford, professor of neurology and pediatrics at Johns Hopkins Children's Center. "A recent study on the natural history of infants with Type I SMA showed that half of infants with Type I SMA had died or been put on permanent ventilation by about 10 months of age. In that study, this number increases to 80 percent by 18 months of age. These data are relevant for the study reported today as the characteristics of the infants evaluated in the natural history study are similar to the infants in this study."
Isis plans to present additional detail from this study at the upcoming American Academy of Neurology conference on April 29, 2014.
Conference Call
At 8:30 a.m. Eastern Time Monday, February 24, 2014, Isis will conduct a live conference call to discuss the top-line results from this study. Interested parties may listen to the call by dialing 866-652-5200, or access the audio webcast at www.isispharm.com. A webcast replay will be available for a limited time at the same address.
