Pfizer is paying Israeli company Protalix $60 million up front in a deal to develop and commercialize the latter’s lead Gaucher disease enzyme replacement therapy, taliglucerase alfa. Protalix could potentially receive another $55 million in regulatory milestones.
Under the terms of the agreement, Pfizer has exclusive commercialization rights to taliglucerase alfa worldwide excluding Israel, where Protalix has retained relevant rights. Pfizer and Protalix will also share future revenues and expenses relating to development of taliglucerase alfa on a 60:40 percent basis, respectively.
Taliglucerase alfa is a plant cell-expressed form of glucocerebrosidase, which has successfully completed Phase III trials. Protalix is currently preparing to complete its rolling NDA for the therapy in the U.S. The drug has been granted orphan drug designation and fast track status as well as emergency use authorization due to a shortage in Cerezyme, the only approved treatment for Gaucher. Genzyme, which makes Cerezyme, was forced to halt production of the drug after contamination issues at one of its bioreactors surfaced.
Hence Protalix’ taliglucerase alfa is already being made available to patients in the U.S. via an FDA-approved expanded access program. It is also provided to patients in the EU under a compassionate use protocol. Shire's late-stage velaglucerase alfa is also similarly approved for emergency use in Gaucher patients.
Taliglucerase alfa has been developed using Protalix’ plant cell culture-based ProCellEx™ system for the expression and manufacture of recombinant proteins. The company claims the ProCellEx platform is capable of producing proteins with an amino acid structure practically equivalent to that of the desired human protein and with very similar glycan structures.
Protalix is exploiting the technology primarily for the development of proprietary and biosimilar recombinant proteins that are therapeutically equivalent or superior to existing recombinant proteins on the market. The company’s preclinical pipeline includes: PRX-102, an alpha galactosidase enzyme for the treatment of Fabry disease; pr-antiTNF, a biosimilar version of Enbrel, which is approved for rheumatoid arthritis, psoriasis, ankylosing spondylitis, psoriatic arthritis, and juvenile rheumatoid arthritis; and an acetylcholinesterase product in development with the Yissum Research and Development Company. An IND filing for the acetylcholinestase product is expected to be filed by the end of 2009.