Since FDA approval of Spinraza nearly a decade ago, Biogen’s spinal muscular atrophy (SMA) treatment has gained rapid momentum, achieving blockbuster-level sales in its second year on the market. Since then, Spinraza has been a reliable revenue contributor, but rival drugs from Roche and Novartis have taken away some of Spinraza’s momentum over the years.
Biogen is poised to have an answer, as the FDA has approved a higher-dose version of its SMA blockbuster. The new version features an “accelerated loading phase” of two 50 mg doses administered 14 days apart, followed by a maintenance dose of 28 mg every four months. Conversely, the lower-dose version of Spinraza features four dose-loading phases that take approximately two months to complete.
In a conference call last month, Biogen CEO Chris Fiebacher highlighted the “much higher level of efficacy” seen in studies of the higher-dose version, saying, “This suggests there is a significant benefit to reaching therapeutic levels sooner.” Regarding high-dose launches in other countries, he said Biogen is encouraging “adoption” by treatment-naïve patients and “switchback” from patients from competing products.
Supporting this approval are data from the Phase 2/3 DeVoto trial, which showed that untreated symptomatic SMA infants who received the drug had statistically significant improvements in motor function compared to untreated control groups from previous studies. Specifically, in a previous study of the lower-dose version of Endia, patients treated with Devoto experienced a 15.1-point improvement on the Children’s Hospital of Philadelphia Infant Neuromuscular Disorders Examination Scale, compared to an 11.1-point decline in untreated patients.
In the open-label portion of the study, patients who had previously received a lower dose of SPINRAZA transitioned to the higher-dose version and experienced improvements in motor function after switching.
The approval of high-dose Spinraza represents Biogen’s answer to Roche’s Everyday, which won FDA approval in 2020 as the first liquid drug to be administered orally or through a feeding tube. A year ago, Roche’s drug won FDA approval in pill form, further increasing its desirable competitive edge. In a recent investor presentation (PDF), Roche said Evrysdy is a “leader” in the SMA space, treating more than 21,000 patients.
Moreover, even though Novartis’ Zolgensma is a gene therapy drug, which means it has its own competitive considerations, the breakthrough drug has still been able to churn out blockbuster-level sales for many years.
Biogen’s Spinraza had sales of $1.55 billion last year, compared to Roche’s Everyday’s sales of Swiss francs 1.76 billion ($2.11 billion) and Novartis’ Zolgensma’s sales of $1.23 billion.
Biogen CEO Viebacher said on a conference call last month that “effectiveness and convenience” are important considerations for doctors treating SMA patients.
“When you ask them about efficacy, most people believe it really is Spinraza, but at some point the convenience of oral administration starts to attract patients,” he says. With the higher-dose version of Spinraza, “the level of efficacy is going to increase dramatically, and I think it will make the choice between oral medication and efficacy more difficult for some physicians and parents.”
Biogen plans to launch a new version of Spinraza in the United States in the coming weeks. It is already being rolled out in some countries overseas.
