CHMP recommends Strensiq (asfotase alfa) for treatment of pediatric-onset hypophosphatasia- Alexion Pharma

Alexion Pharmaceuticals, Inc. announced that the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) has adopted a positive opinion recommending marketing authorization of Strensiq (asfotase alfa).The proposed indication for Strensiq is for long-term enzyme replacement therapy in patients with pediatric-onset hypophosphatasia (HPP) to treat the bone manifestations of the disease. Final decisions from the European Commission are expected in the third quarter of 2015, after which the Company will begin the country-by-country reimbursement processes. Currently, there are no therapies approved for the treatment of HPP.

HPP is a genetic, progressive, ultra-rare metabolic disease in which patients experience devastating effects on multiple systems of the body, leading to debilitating or life-threatening complications. It is characterized by defective bone mineralization that can lead to deformity of bones and other skeletal abnormalities, as well as systemic complications such as profound muscle weakness, seizures, pain and respiratory failure leading to premature death in infants.

The proposed indication for Strensiq is for long-term enzyme replacement therapy in patients with pediatric-onset HPP to treat the bone manifestations of the disease. HPP is associated with multiple bone manifestations including rickets/osteomalacia, altered calcium and phosphate metabolism, impaired growth and mobility, respiratory compromise that may require ventilation, and vitamin B6-responsive seizures. The natural history of untreated infant hypophosphatasia patients suggests high mortality if ventilation is required.

In clinical trials, 71% of infant patients treated with Strensiq who required ventilation support remain alive and continue on treatment. As noted in the CHMP Summary of Opinion, the benefit of exposure to Strensiq is an improvement in skeletal structure, as demonstrated by x-ray appearance of joints, by histological appearance of bone biopsy material, and by apparent catch-up height-gain. The CHMP based its opinion on clinical data from 68 patients with pediatric-onset HPP (ranging from newborns to 66 years of age) enrolled in three pivotal prospective studies and their extension.

Comment: Strensiq has breakthrough therapy designation at the FDA and was filed on 24 July 2014 .