Roche has reported the latest longer-term efficacy and safety results from two Phase III clinical trials of Enspryng (satralizumab) for the treatment of neuromyelitis optica spectrum disorder (NMOSD).

A rare debilitating disease, NMOSD impacts the central nervous system.

Designed by Roche subsidiary Chugai, Enspryng is a humanised monoclonal antibody. It acts on interleukin-6 (IL-6) receptor activity.

The Phase III SAkuraStar and SAkuraSky trials are analysing Enspryng to treat NMOSD patients.

The SAkuraStar trial analysed the efficacy and safety of the drug monotherapy in adult subjects while SAkuraSky assessed the efficacy and safety of Enspryng plus baseline immunosuppressive treatment in adult and adolescent subjects.

Time to first protocol-defined relapse (PDR) during the double-blind period, as assessed by an independent review committee, was the primary goal of the trials.

According to the findings, besides demonstrating a favourable benefit-risk profile, the drug could effectively lower relapses over four years of treatment in individuals suffering with anti-aquaporin-4 antibody (AQP4-IgG) seropositive NMOSD.

Headache, drop in white blood cell count, hyperlipidaemia, arthralgia and injection-linked reactions were the most common adverse reactions observed in the trials without any new safety signals being reported.

Four-year open-label extension data from SAkuraStar and SAkuraSky trials found that 73% and 71% of AQP4-IgG seropositive NMOSD patients receiving Enspryng were relapse-free after 192 weeks, respectively.

Furthermore, 90% and 91% of the subjects in the SAkuraStar and SAkuraSky trials, respectively, were free of severe disease relapse.

The latest data show the therapy’s strong and continued longer-term efficacy in averting relapses.

Enspryng had shown a favourable safety and tolerability profile during the overall treatment period of up to seven years, which is in line with the double-blind periods in both the trials.

Roche Global Product Development head and chief medical officer Levi Garraway said: “We are pleased that these longer-term data further reinforce the previously observed efficacy and safety of Enspryng, which was specifically designed for this lifelong, chronic disease by targeting the IL-6 pathway to reduce the frequency of relapses.

“Enspryng is the only treatment for NMOSD that can be administered subcutaneously at home and has now been approved in over 50 countries.”

The company is currently launching a Phase IIIb SAkuraBONSAI trial of the Enspryng monotherapy to investigate disease activity and progression in NMOSD patients.

Last month, Roche reported the latest results from the Phase III IMpower010 trial where its Tecentriq (atezolizumab) offered substantial disease-free survival (DFS) benefit in individuals suffering with Stage II-IIIA non-small cell lung cancer (NSCLC) whose tumours express PD-L1≥1%.