Target Enrollment in Child Spinal Muscular Atrophy Study Earns Ionis $2M Payment From Biogen

Ionis Pharmaceuticals announced it has completed its target enrollment of the Phase 3 CHERISH study, a trial designed to support marketing approval of the drug candidate nusinersen in children with spinal muscular atrophy (SMA).

The achievement earned Carlsbad, California-based Ionis a milestone payment of $2.15 million from Biogen, of Cambridge, Mass.

According to Genetics Home Reference, SMA affects 1 in 6,000 to 1 in 10,000 people. It is a genetic disease that affects the control of muscle movement, caused by the absence or defect of the survival motor neuron 1 (SMN1) gene, which in turn decreases the production of the survival motor neuron (SMN) protein, essential for the healthy maintenance and survival of motor neurons. Mutations in other genes are also known to cause SMA.

Nusinersen is a drug in clinical trials designed to increased production of the SMN protein by altering the splicing of SMN2, a gene closely related to the SMN1 gene, therefore compensating for the loss or defect of this gene.

The drug has been granted orphan drug status — meaning it has a limited potential for commercial profit — and fast-track designation (to meat an unmet medical need for a serious condition) by the U.S. Food and Drug Administration. It was also granted orphan drug designation by the European regulatory agency.

Nusinersen is under development through an alliance between Ionis Pharmaceuticals and Biogen. The drug is in a number of clinical trials, including four Phase 2 studies and two Phase 3 studies.

One Phase 3 study, ENDEAR, is a 13-month with 110 infants with SMA; it investigates the safety and efficacy of nusinersen with the aim of “event-free survival.”

The CHERISH Phase 3 study (clinicaltrials.gov, NCT02193074) is a 15-month trial with 117 children with between the ages of 2 and 12. Its primary goal is change in the Hammersmith Functional Motor Scale-Expanded (HFMSE), a measure that evaluates changes in muscle function in patients with SMA, achieved by 12 mg doses of nusinersen.

B. Lynne Parshall, chief operating officer at Ionis Pharmaceuticals, said in a press release, “Achieving our target enrollment number in CHERISH brings us one step closer to a marketing application for children with SMA. We also plan to complete enrollment in ENDEAR, our Phase 3 study evaluating nusinersen in infants with SMA, in the first half of this year. This progress sets the stage for Phase 3 data from both of these programs in 2017.

“We would like to thank the parents and families for their participation in CHERISH as well as the investigators and sites for the achievement of this milestone,” Parsall said. “We also appreciate the support from the broader SMA community. We, along with Biogen, are committed to advancing nusinersen toward the market as rapidly as possible.”