US-based Alexion Pharmaceuticals has obtained orphan drug designation (ODD) from Japan’s Ministry of Health, Labour and Welfare (MHLW) for its Soliris (eculizumab) for the treatment of neuromyelitis optica (NMO).

Soliris is a first-in-class terminal complement inhibitor, developed and commercialised by Alexion.

"We look forward to evaluating the clinical benefits of eculizumab in NMO in our registration study, known as PREVENT, which is currently enrolling patients."

The company is enrolling patients with relapsing NMO in a multinational, placebo-controlled registration trial of eculizumab, named the Prevention of Relapses and EValuation of Eculizumab in NMO Treatment (PREVENT) study.

Alexion Pharmaceuticals executive vice-president and R&D head Martin Mackay said: "The orphan drug designation for eculizumab for NMO highlights the significant need for an effective and innovative treatment option for patients in Japan suffering from this debilitating and life-threatening disease.

"By specifically inhibiting the terminal complement pathway, eculizumab has the potential to improve outcomes for patients with NMO. We look forward to evaluating the clinical benefits of eculizumab in NMO in our registration study, known as PREVENT, which is currently enrolling patients."

Solaris received approval in the US, European Union (EU), Japan and other countries, to treat patients with paroxysmal nocturnal haemoglobinuria (PNH) and atypical haemolytic uremic syndrome (aHUS), two life-threatening disorders caused by chronic uncontrolled complement activation.

The company has not received approval for Solaris in any country to treat NMO, while it was granted ODD in the US and EU to treat NMO.

NMO is an ultra-rare neurologic disorder that results in severe damage to the central nervous system (CNS).