FSMA Reports Encouraging Findings for Phase 1 Study

• By Laurie Watanabe
• Sep 30, 2013

Families of Spinal Muscular Atrophy (FSMA) has announced encouraging results from a phase 1 study involving a drug called ISIS-SMNRx.

The drug, produced by Isis Pharmaceuticals headquartered in Carlsbad, Calif., was administered in a single dose to 24 children with spinal muscular atrophy (SMA). The children were then examined for motor function between nine and 14 months after they received their injections.

Researchers used the Hammersmith Functional Motor Scale-Expanded (HFMSE) when examining the children.

They reported that children who received the highest dosage (6mg or 9mg) "continued to show improvements in muscle function tests up to 14 months after a single injection of the drug," FSMA said in a news announcement.

The children who received the very highest dosage of 9mg "showed continuing improvements during follow-up, with no children declining," the announcement added.

B. Lynne Parshall, COO at Isis Pharmaceuticals, said of the results, "We are pleased with the progress we are making on ISIS-SMNRx. Although there was no placebo group, the continuing improvement for up to a year after a single dose observed in this study is encouraging, particularly when considered within the context of the dose response."

Isis is currently administering a phase 2 study and says it has completed dosing for the participating SMA Type 1 infants scheduled to receive a 6mg dose. Other infants in the phase 2 study will receive a 12mg dose instead of the previously planned 9mg. Parshall said the dosage has been increased "based on the safety, pharmacokinetic and pharmacodynamic profile of ISIS-SMNRx we have observed to date."

Additional phases of the study will involve children with SMA Types 2 and 3. Isis would like to offer a 12mg dose to a group of those participating children, Parshall says, and is working with the FDA about the agency's "expressed reservations" over the higher dosage.