FDA grants "Breakthrough Therapy" status for Alexion's asfotase in HPP; issues CRL for Valeant's efinaconazole

US drugmaker Alexion Pharmaceuticals (Nasdaq: ALXN) says that the Food and Drug Administration has granted Breakthrough Therapy designation for its asfotase alfa for the treatment of patients with hypophosphatasia (HPP) whose first signs or symptoms occurred prior to 18 years of age, including perinatal-, infantile- and juvenile-onset forms of the disease.

Alexion gained rights to asfotase along with its 2011 acquisition of Enobia Pharma for an upfront payment of $610 million plus a potential $470 million on the achievement of regulatory and sales milestones (The Pharma Letter December 30, 2011).

The FDA also confirmed that adult-onset HPP is “a serious and life threatening disease or condition” and that Breakthrough Therapy designation – which is intended to expedite development and approval - could be obtained for this aspect of the disease with additional clinical information.