Isis gears up for Phase III with Biogen-partnered antisense drug

Carlsbad, CA's Isis Pharmaceuticals ($ISIS) is touting mid-stage results for its in-development spinal muscular atrophy treatment, setting its sights on a Phase III study and sending its shares up about 15%.

ISIS-SMNRx, one of four antisense drugs covered by a $299 million pact with Biogen Idec ($BIIB), is designed to treat children with the rare disease, and, in top-line results from a mid-stage study, the orphan therapy was well-tolerated and charted dose-dependent increases in muscle function, Isis said. At 9 months, kids on the highest dose improved their muscle function by an average of 3.7 points on the Hammersmith Functional Motor Scale-Expanded, which measures changes in function in SMA patients, according to the company. Isis is saving the full data for April's American Academy of Neurology meeting.

The ongoing multiple-dose study comes on the heels of a positive single-dose trial, Isis said, and the encouraging interim results are promising enough to merit taking ISIS-SMNRx into Phase III later this year, Chief Operating Officer B. Lynne Parshall said.

But it remains unclear whether Isis' amassed data are enough to convince Biogen. Under their 2012 agreement, Biogen has the right to license each drug until a specific point in development, and with ISIS-SMNRx's coming up, the biotech giant has yet to opt in.

Investors, however, seem to think it's likely to happen, as the interim data announcement sent Isis' shares to an all-time high of $59.33 on Friday morning, and the company has risen nearly 700% since it first signed the antisense deal with Biogen.

ISIS-SMNRx is a synthetic drug designed to boost the production of the protein SMN, a lack of which imperils the nerve cells responsible for muscle growth and function, leading to SMA. The disease affects as many as 35,000 U.S. patients, according to Isis.

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