Isis Pharmaceuticals provided an update on its ongoing open-label Phase 2 clinical study of ISIS-SMNRx in infants with Type I spinal muscular atrophy (SMA). Previously the company reported data from this study on event-free survival, measures of muscle function and assessments of developmental milestones. The data reported now shows continued increases in median event-free survival and muscle function scores as well as achievement of developmental milestones. The safety and tolerability profile of ISIS-SMNRx to date continues to support further development. Isis is currently collaborating with Biogen to develop and potentially commercialize ISIS-SMNRx to treat patients with SMA.
The study was designed to evaluate the safety and tolerability of ISIS-SMNRx in infants with Type I SMA and to explore potential efficacy endpoints to support the Phase 3 program. A total of 20 infants with SMA were dosed with either 6 mg or 12 mg of ISIS-SMNRx. SMA infants 7 months or younger entered the study sequentially, such that the dosing of infants in the 12 mg cohort began five to 15 months after the first infant was dosed in the 6 mg cohort. Nineteen infants completed the three induction doses and are evaluable for efficacy. Clinical efficacy endpoints include event-free survival, as defined by time to permanent ventilation or death; CHOP-INTEND motor function scores; and assessments of developmental milestones.
Based on the results shown in this most recent report:
- ISIS-SMNRx is safe and well tolerated in infants with SMA type I. This means that the clinical trials should continue to move ahead as currently planned.
- The next step for this and the other ongoing trials is to prove the efficacy of SMNRx against a placebo control.
- All signs show that this program should continue to move ahead at a rapid pace.
Cure SMA Seed Funding
From 2003 to 2006, Cure SMA provided the seed funding needed to begin investigation into this therapeutic approach.
Several Cure SMA grants totaling over $500,000 were given to U Massachusetts, to help develop the intellectual property needed to investigate antisense oligonucleotides for SMA. The intellectual property generated with our funding was then licensed to Isis Pharmaceuticals to create ISIS-SMNRx.
Currently, Isis and Biogen are conducting four ongoing trials of ISIS-SMNRx:
- ENDEAR, a Phase 3 clinical trial testing infants with SMA type I.
- CHERISH, a Phase 3 clinical trial testing children age 2-12, with onset of symptoms at age six months or later.
- NURTURE, a Phase 2 clinical trial testing very young infants who are genetically predisposed to SMA but not yet showing symptoms.
- EMBRACE, a Phase 2 clinical trial testing other population groups.
There are currently two ongoing controlled phase 3 studies that must remained focused on to provide concrete proof of efficacy.
It is important to focus on completing the two pivotal studies ENDEAR & CHERISH to advance potential regulatory filings as quickly as possible and, equally important, honor the sacrifice of those participating in sham controlled clinical trials, who are contributing to the future of the entire community of families living with SMA.
At next week’s Annual SMA Conference, Isis will be providing additional updates and information on these ongoing clinical trials.