Novartis burnishes Zolgensma data in presymptomatic patients as Roche's Evrysdi continues eating away at the SMA pie
With sales slowing and Roche’s Evrysdi hot on its tail, Novartis’ Zolgensma for spinal muscular atrophy is seeking to build a stable of data in presymptomatic patients to give it a potential new edge. On Friday, the Swiss biopharma teased out some of the first such results.
Zolgensma met its primary and secondary endpoints in a Phase III study cohort, Novartis said, showing that all 14 patients managed to sit independently for 30 seconds and were alive without breathing support at 14 months old. The data come from a group of presymptomatic patients with two copies of the SMN2 gene aged six weeks or younger at the time of administration.
Novartis says most patients with two copies of the gene go on to develop SMA Type 1, which accounts for 60% of all cases. The biopharma is also evaluating Zolgensma in 15 patients with three SMN2 copies in a separate cohort, for which the trial remains ongoing.
For the secondary survival goal, the figure compared favorably to a natural history cohort, Novartis added. Only 26% of patients in the historical group didn’t need breathing help at 14 months, per a study from a pediatric neuromuscular research database.
“When treated with Zolgensma prior to the onset of symptoms, not only did all patients survive, but were thriving — breathing and eating on their own and sitting independently, with many standing and walking,” Novartis Gene Therapies CMO Shephard Mpofu said in a statement.
On safety, every patient experienced at least one side effect, 10 of which were determined to be treatment-related. There were no serious adverse events related to Zolgensma, Novartis said, but five patients reported unrelated events that resolved on their own.
Novartis concurrently released data from another study in Europe looking at patients with SMA Type 1 who had bi-allelic SMN1 gene deletion or point mutations and one or two copies of SMN2. This trial measured patients younger than six months and included some with more severe disease at baseline compared to its US counterpart study.
Among 33 enrolled patients, 27 achieved motor milestones not usually seen in the natural course of SMA, Novartis said. And 31 of 32 patients who completed the study were alive without breathing support at 14 months, again compared to the 26% in the natural history cohort. The biopharma had previously reported interim data from this trial, showing the majority of participants performed better than expected in certain milestones.
Zolgensma’s open-label presymptomatic study comes as Evrysdi tallied a 72% increase in sales from the fourth quarter in 2020, notching $86 million in 2021’s first three months. The sharp uptick comes despite Evrysdi’s approval just last August, indicating the oral SMA drug proved appealing to patients’ families amidst the ongoing Covid-19 pandemic.
Novartis is also competing with Biogen’s Spinraza, the first approved SMA drug back in 2016. It’s quickly become a crowded space with the companies jostling for position. While Zolgensma is a one-time treatment, it’s been criticized for its exorbitant $2.1 million cost that makes it the most expensive drug on the planet.
Spinraza, meanwhile, costs $750,000 for the first year and then $375,000 every subsequent year, but sales have lagged since the end of 2019. Evrysdi maxes out at $340,000 annually, though the cost for an infant weighing 15 pounds who is less than two years old is less than $100,000.