Roche’s Soliris rival Enspryng bags FDA approval

Roche’s neuromyelitis optica spectrum disorder (NMOSD) drug Enspryng has scored US Food and Drug Administration (FDA) approval, setting up a market clash with Alexion’s Soliris.

Enspryng (satralizumab) has been approved to treat adult patients living with anti-aquaporin-4 (AQP4) antibody positive NMOSD, a rare autoimmune disorder of the central nervous system which is often misdiagnosed as multiple sclerosis.

The first approved treatment in the US for NMOSD is Alexion’s complement C5 inhibitor Soliris (eculizumab), which scored FDA approval in June last year. It is also indicated for use in adult NMOSD patients who are AQP4 antibody positive.

Roche’s Enspryng is a modified version of its interleukin-6 inhibitor Actemra (tocilizumab), which recently re-entered the spotlight as a potential treatment for COVID-19. Like Actemra, Enspryng is designed to inhibit cytokines that play a key role in inflammatory processes.

The new NMOSD treatment was originally designed by Roche’s Japanese subsidiary Chugai, using novel recycling antibody technology.

“The FDA approval of Enspryng, the first subcutaneous NMOSD treatment using novel recycling antibody technology, builds upon the work we’ve done in multiple sclerosis with Ocrevus to develop first-in-class medicines and further the scientific understanding of neuroimmunological diseases,” said Levi Garraway, chief medical officer and head of global product development at Roche.

The approval is supported by results from two phase 3 clinical trials – SAkuraStar and SAkuraSky – in which Enspryng given as a mono therapy achieved a 55% reduction in the risk of relapse in NMOSD patients.

In the overall patient population, 76.1% were relapse-free at week 48 and 72.1% were relapse-free at 96 weeks, compared 61.9% and 51.2% respectively in the placebo arm.

In addition to the main patient population that was studied, Enspryng scored positive results from specific subgroups of aquaporin-4 (AQP4-IgG) seropositive and seronegative patients.

This group reflects a real-world population of adolescents and adults with NMOSD who tend to experience a more severe disease course.

Out of the AQP4-IgG seropositive subgroup analysis, three of 27 patients (11%) on the treatment arm experienced a protocol-defined relapse (PDR) compared to 12 of 28 patients (43%) in the placebo arm.

In the AQP4-IgG seronegative subgroup, five of 14 patients (36%) treated with Enspryng experienced a PDR compared to six of 14 patients (43%) receiving the placebo treatment.

Roche has already submitted regulatory filings for the drug with the European Medicines Agency (EMA) and China’s National Medical Products Administration.