Pfenex Reports Good Results of Biosimilar for Osteoporosis

Biotechnology firm Pfenex recently reported results from its phase 3 PF708-301 study, which showed comparable overall profiles between its biosimiliar drug candidate PF708 and Eli Lilly’s teriparatide (Forteo) for osteoporosis.

The biotechnology firm Pfenex recently reported results from its phase 3 PF708-301 study, which showed comparable overall profiles between its biosimiliar drug candidate PF708 and Eli Lilly’s teriparatide (Forteo) for osteoporosis.

Patients with osteoporosis received 24 weeks of daily injections. Pfenex, expects to submit a New Drug Application (NDA) to the FDA in the third quarter of 2018.

PF708 is a teriparatide drug candidate that is being developed as a therapeutic equivalent to teriparatide, which is used in patients at a high risk of fracture. Teriparatide, a recombinant human parathyroid hormone, is an anabolic agent that stimulates bone formation.

The PF708-301 study enrolled a total of 181 patients, with 90 patients receiving PF708 and 91 receiving teriparatide. There were 82 patients who completed the study in the PF708 treatment group, compared with 81 patients in the teriparatide treatment group. The primary study endpoint was anti-drug antibody (ADA) incidence after 24 weeks of drug treatment.

There were 2 PF708-treated patients and 2 teriparatide-treated patients that developed ADA during the study. These low rates of immunogenicity are consistent with historical teriparatide results (~3%) in patients with postmenopausal osteoporosis.

The secondary study endpoints included mean percentage changes in lumbar-spine bone mineral density and median percentage changes in bone turnover markers after 24 weeks of drug treatment, as well as pharmacokinetic parameters for up to 4 hours after the first dose. Safety study endpoints were incidences of adverse events and serious adverse events.

According to The Center for Biosimilars®, teriparatide follow-on products are regulated as biosimilars in the European Union (and biosimilars including Gedeon Richter’s Terrosa and Stada’s Movymia have already been approved for marketing). But in the United States, they are regulated as drugs. As such, Pfenex will submit to the FDA a NDA, rather than a Biologics License Application, for PF708.