San Diego Business Journal

A recent study found possible evidence that a blockbuster drug developed by Carlsbad’s Ionis Pharmaceuticals benefits older children and teens with a severe neuromuscular disorder.

The findings, which didn’t demonstrate cause and effect, could nonetheless lead to more prescriptions of spinraza for spinal muscular atrophy. This disease attacks nerve cells in the spinal cord, making breathing, walking and head control difficult.

In 2018, Ionis made $238 million from spinraza, more than double than the prior year. Biogen, based in Massachusetts, markets the drug.

Spinraza won approval in late 2016 as the first treatment for spinal muscular atrophy, based on positive clinical trial results. Post-approval studies continued, showing how the drug works in an older population.

The three-year study, recently published in the medical journal American Academy of Neurology, included 28 participants who were up to age 15 during enrollment. It found an association between condition improvements and spinraza, but noted the results do not prove cause and effect.

Researchers also cautioned the study was limited by the small number of participants, an open-label design where participants were aware they were taking the treatment, and the lack of control groups.

Still, the results could make prescribers more comfortable with spinraza in an older population.

There are several types of spinal muscular atrophy, or SMA. The most severe form, SMA type 1, occurs before the age of six months. It’s marked by infants never gaining the ability to sit up and a median survival rate of 14 months.

The study included SMA type II — babies showing symptoms after six months who can sit up — and type III, in which babies present symptoms later and learn to walk but become progressively weaker.

“We were excited to see that the drug can show benefit for these older kids too and that the benefit can extend for this period of time,” said study author Dr. Basil T. Darras of Boston Children’s Hospital and Harvard Medical School.

“The children’s motor function improved, and their disease activity stabilized in ways that were definitely not consistent with the normal history of this disease.”

Spinraza was Ionis’ first blockbuster drug. The company, formed in 1989, has an extensive pipeline.

It pioneered what are called antisense drugs that bind to RNA instead of proteins, which have long been the focus of the pharmaceutical industry.