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Investigational Therapy for Hemophilia A Comes up Short in Trial

June 2, 2017

One of Shire’s investigational therapies, known as SHP656, failed to show significant efficacy in a phase I/II clinical study. The therapy was being developed as an extended half-life treatment for hemophilia A using proprietary technology from Xenetic Biosciences.

Xenetic’s PolyXen™ platform technology works by attaching polysialic acid (PSA) to an existing protein, in this case factor VIII, to make the therapy more stable and less detectable by the immune system, thereby slowing the protein’s natural degradation process in the bloodstream. PSA is a unique carbohydrate polymer which consists of sialic acids linked together.

If successful, SHP656 could prolong the circulating half-life of FVIII, allowing for more sustained protection from bleeding and less frequent infusions for hemophilia A patients. Unfortunately, efficacy was not achieved in the phase I/II trial, which was designed in part to evaluate the use of SHP656 via a once-weekly dosing schedule. It should be noted that no drug-related adverse events, serious adverse events, or rFVIII inhibitors were reported.

“While Shire is disappointed by this outcome, the company is encouraged by the knowledge gained through this research and remains committed to transforming the treatment landscape for patients with bleeding disorders,” Philip Vickers, Ph.D., Shire’s global head of R&D, said in a statement.

The poor efficacy results do not necessarily preclude future collaborations between the companies or continued development of the PolyXen™ platform. “Given the potential application of polysialic acid technology, the companies will explore future collaborations,” Dr. Vickers added.  

“Moving forward, we believe data from Shire’s SHP656 program continues to support the broad utility of our proprietary PolyXen technology platform, and we remain focused on building a growing pipeline of partnerships utilizing this proven platform,” Xenetic CEO M. Scott Maguire stated. “We truly value our continuing relationship with Shire and look forward to exploring other potential applications of PolyXen within the Shire portfolio.”

Source: Genetic Engineering & Biotechnology News, May 22, 2017