Roche's low-price Evrysdi will take 'meaningful' SMA share from Biogen's Spinraza: analyst

Biogen’s blockbuster spinal muscular atrophy therapy Spinraza has been holding its ground despite recent competition from Novartis’ one-time gene therapy Zolgensma. But that will likely change, thanks to a new entrant.

The FDA on Friday approved Roche’s Evrysdi for SMA patients 2 months and older. As SVB Leerink analyst Mani Foroohar sees it, the drug could steal “meaningful share” from Spinraza because of a broad label for all subtypes of the genetic disorder, convenient oral dosing and—perhaps most importantly—a lower price tag.

Just how meaningful a loss could Biogen be looking at? Foroohar now projects Spinraza sales will peak in 2021 at $2.5 billion, up from $2.1 billion in 2019; after that, it will roll back to $2.3 billion in 2022 and then drop further to $1.9 billion in 2023.

Foroohar only gives Spinraza credit for an extra year of modest growth because “most of its sales growth today is coming from lower reimbursement markets overseas that have not yet had Zolgensma or [Evrysdi] launches,” he wrote in a Monday analysis. Roche has already filed Evrysdi for approvals in many other countries, including China, and an EU application is near.

Nevertheless, he figures Biogen could soften the blow by churning out more promising data. These include the Devote study, which is testing Spinraza at a high, investigative maintenance dose of 28 mg, compared with the FDA-approved 12 mg dose. The Big Biotech also just launched the Respond trial, aiming to find out whether Spinraza can benefit those who have had a suboptimal response to Zolgensma. Plus, even longer-term follow-up beyond five years of treatment in pre-symptomatic SMA patients in the Nurture study might also help.

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But Spinraza needs to defend against the relatively low-cost Evrysdi now, too. Roche priced Evrysdi based on patient weight. For an infant under 15 pounds—usually 2 years of age—the annual price checks in at less than $100,000, and it’s capped at $340,000 per year, or 44 pounds, normally around the weight of a 6-year-old. Even at its maximum, Evrysdi’s list price comes at a discount to Spinraza’s low-end, maintenance price of about $382,500, Foroohar noted.

Evrysdi’s price was “slightly surprising” to RBC Capital Markets analyst Brian Abrahams, who previously estimated that Roche would go with a sticker of about $400,000. The reason? Mainly because payers told him they would welcome the Roche drug even if it were priced at parity with Spinraza. But while a discount means less per-patient revenue, it “may be offset by increased adoption,” he wrote in a Friday note to clients.

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And payers have more to like about Evrysdi beyond price, according to Abrahams. The Roche med boasts the convenience of oral dosing at home, whereas Spinraza is injected into the spinal fluid every four months after an initial four loading doses that occur closer together.

And Evrysdi looks good on the safety side, too. Roche chose to focus on Evrysdi after another RNA splicing modifier developed by partner PTC Therapeutics was placed on clinical hold in 2015 thanks to eye toxicity that emerged in preclinical studies. Although no such safety signal was observed in Evrysdi’s clinical trials, industry watchers had been harboring concerns about a potential ophthalmic monitoring requirement on Evrysdi’s label, which would have hurt its oral advantage. But the FDA label doesn’t mandate any such eye exams.

Even with those pros in hand, though, Evrysdi’s expected growth will mainly come at the cost of Spinraza, not Zolgensma, Foroohar predicts. “Given strong data, one-time therapy, and simple IV administration, we see Zolgensma as remaining the treatment of choice for very young SMA patients,” he wrote in the Monday report. In infants, Evrysdi may see a “small revenue opportunity” as a bridging treatment for some patients ahead of Zolgensma, he added.