Isis Pharmaceuticals’ Spinal Muscular Atrophy Drug Advances in Phase 2 Trials


A press release from Isis Pharmaceuticals Inc. (NASDAQ:ISIS) on Friday announced a phase 2 study evaluating the company’s investigational spinal muscular atrophy drug, known as ISIS-SMN, which is designed to treat all types of SMA. The company said Friday that the first child was dosed in its midstage study with 12 milligrams of ISIS-SMN after having completed dosing in three initial cohorts of 3 milligrams, 6 milligrams, and 9 milligrams.

The study is being offered to children with spinal muscular atrophy (SMA) who have completed dosing in Isis’s previous studies. Isis is also running an ongoing similar study for infants with a more severe type of SMA, which has been extended. The first infant in the study has received the fourth dose in its multiple-dose, dose-escalation phase 2 study, having received the first three initial doses, Isis said Friday.

SMA is a genetic disease that attacks a person’s spinal nerve cells, which are responsible for communication with voluntary muscles such as arm muscles and leg muscles. As nerve cells in the spine are destroyed, the muscles weaken, eventually affecting a person’s ability to walk, talk, breathe, and swallow. There is currently no cure for the disease, and the severity of the disease varies from individual to individual; some people diagnosed with SMA will have a normal life expectancy with the disease, while for others, it can be fatal.

SMA affects between 30,000 to 35,000 people in the U.S., Europe, and Japan. Infants with a severe type of SMA, known as Type 1 SMA, have a life expectancy of just two years, while children with Type II SMA, which is slightly less severe, have a significantly shortened lifespan and are never able to stand independently.

Isis will receive two milestone payments for the two studies for a total of $7.3 million toward the continuation and advancement of the studies. The studies are being carried out in partnership with Biogen Idec, a pharmaceutical company based in Massachusetts.

“This year we anticipate making significant progress in this and other programs we are working on with the Biogen Idec team,” said B. Lynn Parshall, the chief operating officer at Isis. “The ongoing multiple-dose studies in infants with Type 1 and in children with Type II and Type III SMA are progressing, and we look forward to sharing the top-line data from these studies this quarter and more detailed results at the American Academy of Neurology meeting in April,” per Isis’s press release.

Isis’s drug, ISIS-SMN, is designed to alter the splicing of a closely related gene in order to increase the production of SMN protein; the Food and Drug Administration has granted Isis orphan drug status and has fast-tracked the medicine for the treatment of patients with SMA.