Taliglucerase alfa: Additional Phase III data

Top-line data from 26 evaluable patients in an open-label, crossover, international Phase III trial showed that mean hemoglobin and platelet counts, spleen volume and liver volume remained stable after patients switched from Cerezyme imiglucerase to an equivalent dose of IV taliglucerase alfa every 2 weeks for 9 months. One patient experienced a hypersensitivity reaction. The trial was originally designed to enroll 15 patients, but was expanded to include 30 patients as a result of the shortage of enzyme replacement therapy for Gaucher's patients. Genzyme Corp., a subsidiary of Sanofi (Euronext:SAN; NYSE:SNY), markets Cerezyme and has faced supply shortages of the Gaucher's disease drug since 2009 due to viral contamination and other problems at the company's Allston, Mass. facility (see BioCentury, Aug. 30, 2010). Protalix previously reported preliminary data from 15 patients in the trial showing that switching from Cerezyme to an equivalent dose of IV taliglucerase alfa led to no increased safety concerns while maintaining efficacy (see BioCentury, Nov. 8, 2010).

In February, FDA issued a complete response letter for an NDA from Protalix for taliglucerase alfa in which the agency requested CMC information about testing specifications and assay validation, as well as additional data from ongoing switchover and extension studies, but did not request additional trials (see BioCentury, Feb. 28). Protalix said it included the additional data from the switchover study in its response to FDA's complete response letter last week. The submission also included data from treatment-naïve patients who completed a Phase III trial and continued to receive taliglucerase alfa for >24 months in a long-term extension trial, as well as additional CMC analyses. Protalix said patients in the extension study continued to show an improvement in efficacy and that taliglucerase alfa was well tolerated. Protalix said it expects FDA to provide an updated PDUFA date within weeks. ...