Roche preps filings for satralizumab in rare disease NMOSD

Roche is two for two in its phase 3 trials programme for satralizumab in the rare disease neuromyelitis optica spectrum disorder (NMOSD), setting up regulatory filings.

The interleukin-6-targeting antibody reduced the risk of relapse by 55% compared to placebo in the SAkuraStar trial reported at the ECTRIMS conference in Stockholm this week, backing up the results of the SAkuraSky study reported last year as an add-on therapy .

NMOSD is an autoimmune disease of the central nervous system characterised by unpredictable relapses causing potentially irreversible consequences, such as blindness and paralysis.

Satralizumab performed even better in patients with a specific biomarker – anti-aquaporin-4 (AQP4) antibody – with a 74% reduction in relapses risk compared to placebo.  AQP4 antibodies target and damage specific nerve cells (astrocytes) in optic nerve, spinal cord and brain.

For years there was no specifically approved treatment for NMOSD, is thought to affect around 4,000 to 8,000 patients in the US, with patients treated with immunosuppressants – sometimes alongside corticosteroids – that have a high risk of side effects.

That changed very recently when Alexion got a green light for its complement C5 inhibitor Soliris (eculizumab) in adults with AQP4-positive NMOSD, which in trials reduced the risk of relapse by around 65% after 48 weeks.

Other potential treatments for NMOSD are also coming through the industry pipeline, including Viela Bio’s anti-CD19 antibody inebilizumab, which completed a first phase 3 trial earlier this year that showed a 77% reduction in relapses after 28 weeks in AQP4-positive patients.

Satralizumab seems to have matched the efficacy of these other drugs, which all promise to improve on the safety of treatment, whilst also having activity in all-comer NMOSD patients who don’t have the AQP4 biomarker. That could make it a good first-line option if approved for marketing, as an estimated one-third of patients with NMOSD are AQP4-negative.

“The positive results from the pivotal SAkuraStar and SAkuraSky studies support the hypothesis that IL-6 plays a key role in this devastating disease that can take away people’s independence,” said Sandra Horning, Roche’s soon-to-depart chief medical officer.

“We are encouraged by these results and look forward to working with regulators over the coming months to bring satralizumab to people living with NMOSD as soon as possible,” she added.