Isis Pharmaceuticals has announced today that it plans to add a 12mg cohort to its ongoing phase 1b/2a study evaluating ISIS-SMN in children with spinal muscular atrophy. The higher dose will also be included in an open-label extension study for those children who have completed dosing in previous studies.
According to a press release, the phase 1b/2a study of ISIS-SMN(Rx) is an open-label, multiple-dose, dose-escalation study designed to assess the safety, tolerability and pharmacokinetic profile of the drug in children with spinal muscular atrophy aged between two and 15 who are medically stable. In the ongoing phase 1b/2a study, all patients have completed dosing in the initial three dose cohorts (3mg, 6mg and 9mg) and ISIS-SMN(Rx) has been well tolerated over multiple doses. Patients who have participated in the phase 1b/2a study are eligible to enter an open-label extension study, which is designed to provide a single additional dose of 12mg to the more than 50 children with spinal muscular atrophy who are eligible to roll over into this study. The investigation of the 12mg dose in both studies is anticipated to begin in December or January.
“We are pleased to be able to increase the dose of ISIS-SMN(Rx) based on the safety and tolerability data we have seen to date in both infants and children with spinal muscular atrophy. We have already begun the infant 12mg dose cohort and look forward to sharing data from this study early next year. Considering the encouraging safety profile we have observed in children with spinal muscular atrophy in the lower dose cohorts, the evaluation of the 12mg dose will provide additional information as we move into our Phase 3 programme. We are also pleased that after reviewing the data, the FDA agrees that we can proceed in our investigation of a higher dose,” said B. Lynne Parshall, chief operating officer at Isis.