Biogen ramps up its SMA rivalry with Novartis with new Spinraza trial

Biogen's Spinraza showed signs of sales weakness last quarter, but the company played down new competition from Novartis' Zolgensma. (Biogen)

What do you do when a hot new gene therapy threatens to unseat your drug as the treatment of choice for a devastating disease?

For Biogen, that drug is the $1.7 billion-a-year Spinraza to treat spinal muscular atrophy (SMA), and the competition is Novartis’ gene therapy Zolgensma. Biogen’s latest gambit to preserve its market share has generated some buzz on Wall Street.

Biogen is planning a new trial of Spinraza to investigate much higher doses than what the FDA currently recommends. The trial will enroll 126 patients of all ages, including adults, the company said at the Congress of the European Paediatric Neurology Society (EPNS) in Athens. It will compare a maintenance dose of 28 mg to the currently approved dose of 12 mg.

As the trial first surfaced, Evercore ISI analyst Umer Raffat dashed out a missive to investors—titled “Spinraza on the offensive"—noting that the FDA-approved 12 mg dose was based on data in infants. The possibility of a higher dose working better in teenagers and adults was not investigated in clinical trials.

Therefore, “what we never learned was whether the effect could have been greater at higher doses,” Raffat noted.

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Biogen's ability to answer to that question could be key as Novartis builds a market for Zolgensma. The company rolled out the treatment in March with a controversial list price of $2.125 million. But it already has some payers on board, thanks largely to its willingness to tie reimbursement to performance and make other concessions to lessen the cost burden.

Just last week, Cigna announced a new program that will fully cover Zolgensma, with no out-of-pocket cost for patients. The company worked out a per-member per-month payment schedule that will make it easier to manage the high costs associated with gene therapy, Cigna said.

The insurance community’s willingness to cover Zolgensma is no doubt related to the fact that a one-time treatment offers the potential for some SMA patients to lead nearly normal lives. It’s a strong marketing message to patients, too—one that Biogen will need to counter with as much ammunition as it can gather.

In July, Biogen presented a new Spinraza data set to back up its oft-cited contention that the drug should be the “foundation” of care for SMA. In an ongoing study, 25 patients who are being tracked for up to four years are still alive, and they don’t require breathing assistance from a ventilator, the company said.

Biogen’s Wildon Farwell, executive director and head of late-stage neuromuscular for Biogen, told FiercePharma the results exceeded anything that had been previously reported for patients with SMA. “This is a remarkable result,” he said.

RELATED: With 'remarkable' data, Biogen's Spinraza sharpens its case against Novartis gene therapy

During the Athens conference, Biogen is releasing new data from trials of Spinraza in children with late-onset SMA that show stabilization or improvements in motor function for nearly six years in some patients, the company said.

Will the newly launched Spinraza trial persuade regulators and physicians that the drug is even better at higher doses? Raffat said the study could help fill in holes left by the original clinical trial program. At the time, Biogen extrapolated the 12 mg dose from data showing efficacy in infants, but even the FDA questioned whether that was a clear enough rationale to recommend the same dose for adults.

Biogen might have hesitated to try the higher dose because of side effects its scientists saw in animal studies, but those toxicities appeared at doses four to five times higher than what’s planned for the current study, Raffat noted.

The aggressive development plan for Spinraza certainly makes sense given the challenges it's facing. During the second quarter, sales dropped 6% to $488 million, falling short of analysts’ estimates. It didn’t help that growth outside the U.S. was hampered by price declines in France and flattened sales curves in mature markets.

Still, CEO Michel Vounatsos downplayed the Zolgensma competition, saying it was “premature to make assumptions” about the uptake of gene therapy.