AstraZeneca’s rare diseases unit Alexion has secured Japan’s Ministry of Health, Labour and Welfare (MHLW) expanded approval for its generalised myasthenia gravis (gMG) drug Soliris (eculizumab).

MHLW expands Soliris’ indication to include children who are anti-acetylcholine receptor (AChR) antibody-positive, for whom high-dose intravenous immunoglobulin (IVIG) therapy or plasmapheresis (PLEX) are inadequate to control symptoms.

The expanded approval by MHLW was supported by the results from a Phase 3 clinical trial of Soliris in paediatric patients with refractory gMG.

In the clinical study, Soliris showed significant improvement in the primary endpoint of change in Quantitative Myasthenia Gravis (QMG) total score from baseline, at the 26th week.

QMG is a physician-reported scale assessing disease severity and function.

Soliris showed efficacy and safety in paediatric patients, consistent with the established profile of the drug in clinical trials involving adults with refractory gMG.

The most common adverse events include headache and nasopharyngitis.

Alexion CEO Marc Dunoyer said: “Paediatric patients living with gMG can become nonresponsive to standard treatments and continue to experience symptoms that impact their mobility, speech and breathing.

“Our first-in-class C5 inhibitor Soliris has the potential to improve outcomes and quality of life for paediatric patients and their families, and we take pride in delivering this first and only targeted therapy to the paediatric gMG community in Japan.”

In a separate development, AstraZeneca and Merck (MSD) have received the MHLW approval for a combination of Lynparza (olaparib) plus abiraterone and prednisolone.

The combination was indicated for the treatment of adults with BRCA-mutated (BRCAm) castration-resistant prostate cancer with distant metastasis (mCRPC).

The MHLW approval was based on a subgroup analysis of the Phase 3 PROpel study, which evaluated Lynparza plus abiraterone compared to abiraterone alone in patients with BRCA mutations.

In the Phase 3 study, Lynparza plus abiraterone showed clinically meaningful improvements in both radiographic progression-free survival (rPFS) and overall survival (OS).

Lynparza plus abiraterone showed consistent safety and tolerability with that observed in previous clinical trials and the known profiles of the individual medicines.

AstraZeneca oncology business unit executive vice president Dave Fredrickson said: “This Lynparza combination has been shown to reduce the risk of disease progression or death compared to standard of care and underscores the critical importance of BRCA testing at metastatic diagnosis.

MSD Research Laboratories chief medical officer global clinical development head and senior vice president Eliav Barr said: “It is very important to develop and deliver novel treatment combinations to patients with BRCA-mutated metastatic castration-resistant prostate cancer that improve on the current standard of care.”