Citing 'less-than-optimal' outcomes for Roche's Evrysdi, Biogen launches high-dose Spinraza trial

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Biogen said it plans to launch a trial to test a high dose of Spinraza in patients who've had prior treatment with a rival from Roche. (Biogen)

While much of the attention on Biogen lately has centered on its launch of controversial Alzheimer's disease drug Aduhelm, the company is also feeling the heat from a new challenger in spinal muscular atrophy (SMA). 

Biogen's Spinraza, an SMA drug launched in early 2017, is facing new competition from Roche's 2020 oral entrant Evrysdi. After analyzing data around its new rival, Biogen has unveiled plans to test its drug in patients who've already been treated with Evrysdi.

Available data suggest there are "remaining unmet needs" for some patients treated with Evrysdi, Biogen said in a statement. The company wants to see whether a high dose of Spinraza can help those patients. 

Spinraza, also known as nusinersen, is already approved as a 12-mg dose, and the new trial will test loading doses of 50 mg two weeks apart plus maintenance doses of 28 mg every four months for about 2.5 years. Investigators will enroll children, teens and adults with later-onset SMA after treatment with Evrysdi. The plan is to start enrolling patients this year, Biogen says.

Evrysdi's dosing maxes out at 5 mg when patients reach 20 kilograms in weight, Biogen said. The data suggest patients' exposure to the drug diminishes as they grow, Biogen says.

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

“We believe that lower drug exposure may be contributing to less-than-optimal treatment outcomes for some patients treated with Evrysdi," Biogen's chief medical officer Maha Radhakrishnan, M.D., said in a statement. "The ASCEND study seeks to understand if nusinersen may address that unmet medical need and will help inform the future of SMA treatment, with the hope of improving patients’ outcomes for the long term."

The trial will assess patients' scores on the Revised Upper Limb Module measurement range. Other outcomes will look at safety, caregiver burden and scores on the Hammersmith Functional Motor Scale Expanded metric.

Investigators aim to enroll up to 135 patients. Biogen is already testing a higher dose of Spinraza in another trial called DEVOTE.

RELATED: Biogen's sales slide on Spinraza, Tecfidera as pivotal Alzheimer's decision nears

The ASCEND trial launch comes as Spinraza faces competitive pressure in SMA—both from the Roche launch and Novartis' gene therapy Zolgensma. Since Spinraza is an intrathecal injection and requires a visit to a treatment center, Roche's oral option has been a "more attractive" option for some patients during the pandemic, Biogen CFO Michael McDonnell acknowledged earlier this year. Still, the company believes Spinraza has a “very strong efficacy and safety profile and will continue to be a foundation of care,” McDonnell said at the time.

Amid pandemic challenges last year, Spinraza's sales fell 2% to $2 billion. In the first half of 2021, the drug pulled in $1.02 billion, a slight decline from $1.06 billion during the same period in 2020.

Meanwhile, Biogen also has its hands full with its rollout of Aduhelm, the controversial Alzheimer's drug that scored an FDA approval back in June. Since that accelerated approval, the company and the FDA have faced questions over the process that led to the nod, and insurers have been taking a careful look at the drug's data. A major coverage decision from the Centers for Medicare & Medicaid Services remains outstanding. 

At a recent Morgan Stanley healthcare event, Biogen CEO Michel Vounatsos claimed there's "clearly too much confusion, misinformation and controversy surrounding our data and the approval process." The launch has been "even more gradual than we had expected," he added.