Isis Shares Climb on Early Data for Rare Spine Disorder Drug

2/21/14Follow @benthefidler

Isis Pharmaceuticals could earn a big check if a drug it’s developing for a rare spinal disorder is up to snuff with Biogen Idec. Though that decision hasn’t been made by the Cambridge, MA-based biotech giant just yet, Isis took a step forward with some early results from a mid-stage study.

Carlsbad, CA-based Isis (NASDAQ: ISIS) today reported interim, top-line data from an ongoing Phase I/Phase II clinical trial of ISIS-SMNrx, an experimental treatment for spinal muscular atrophy, a rare genetic disease that causes severe muscle atrophy and weakness in newborns and children.

The early results were positive: Isis said the drug is increasing the muscle function of the children in the study, is working better at higher doses, and is boosting the levels of the key protein—-survival of motor neuron, or SMN—that spinal muscular atrophy patients are lacking. Patients taking the highest (9 mg) dose, for instance, saw their muscle function increase by an average of 3.7 points nine months after their first injection. That score was measured by the Hammersmith Functional Motor Scale-Expanded, a standardized test to gauge changes in muscle function for patients with spinal muscular atrophy.

Isis also said SMN levels of patients on the highest dose of ISIS-SMNrx increased by an average of 115 percent three months after the first injection. Isis didn’t provide much detail on the drug’s safety, but said it’s been well tolerated so far, and that the only two serious adverse events experienced by patients—one of which was pneumonia—weren’t related to the Isis treatment.

“In our view, the data indicates the drug is having the desired effect (increasing SMN protein, improving muscle function) and justifies advancement of the program,” J.P. Morgan analyst Cory Kasimov wrote in a note to investors Friday.

Shares of Isis climbed about 16 percent in early trading.

The data are impressing Isis shareholders, but are the numbers good enough for Biogen (NASDAQ: BIIB)? Isis struck a deal with Biogen two years ago to co-develop ISIS-SMNrx, and has since received more than $45 million in various payments. But the deal also gave Biogen an option to license the drug if it wants to, which would entitle Isis to potentially receive $225 million in a license fee and milestone payments. Biogen has yet to decide whether to opt in on the program, however.

Additionally, Isis will have to show that these protein and muscle function increases translate to a clinically meaningful benefit for patients. Isis is still awaiting data from a second mid-stage study testing its drug in infants with spinal muscular atrophy, as opposed to those who develop the disease in childhood. Chief operating officer B. Lynne Parshall said today’s numbers give Isis “further confidence” to test ISIS-SMNrx in a Phase III trial in children with spinal muscular atrophy later this year.

Spinal muscular atrophy is caused by a faulty version of the SMN1 gene, which doesn’t end up producing enough of the SMN protein to keep muscles strong. The disease affects about one out of every 10,000 newborns. There is no approved cure for it.

Ben Fidler is Xconomy's Deputy Biotechnology Editor. You can e-mail him at bfidler@xconomy.com Follow @benthefidler

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