Isis Pharma To Investigate Higher Dose Of ISIS-SMN Rx In Children With SMA

(RTTNews) - Isis Pharmaceuticals Inc. (ISIS) announced Friday that it plans to add a 12 mg cohort to the ongoing Phase 1b/2a study evaluating ISIS-SMNRx in children with spinal muscular atrophy or SMA. In addition, a 12 mg dose will be included in an open-label extension study for those children who have completed dosing in previous studies.

The company noted that the addition of the 12 mg cohort will allow for the investigation of this dose in support of the Phase 2/3 registration-directed program planned to begin next year.

The Phase 1b/2a study of ISIS-SMNRx is an open-label, multiple-dose, dose-escalation study designed to assess the safety, tolerability and pharmacokinetic profile of the drug in children with SMA between the ages of 2-15 who are medically stable.

In the ongoing Phase 1b/2a study in children with SMA, all patients have completed dosing in the initial three dose cohorts (3 mg, 6 mg and 9 mg) and ISIS-SMNRx 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 12 mg to the more than 50 children with SMA who are eligible to roll over into this study. The investigation of the 12 mg dose in both studies is anticipated to begin in December or January, the company said.