Xenetic Paid $3 Million to Advance Phase 1/2 Trial of Long-acting Hemophilia Therapy

Xenetic Biociences has received a $3 million milestone payment from its partner Shire for advancing the Phase 1/2 clinical trial of PSA-recombinant SHP656, a factor VIII protein, evaluating the drug’s effectiveness as a long-acting therapy for hemophilia A.

Shire’s main objective behind the agreement is to develop a novel FVIII protein that is capable of prolonging its own circulating half-life, allowing for fewer treatment sessions. Higher activity levels would also mean increased effectiveness.

“We are thrilled with the progress that Shire has made developing the SHP656 program, which is currently in Phase 1/2a clinical trials for the treatment of hemophilia,” Xenetic CEO Scott Maguire said in a press release.

“We look forward to the continued development of SHP656 utilizing our proprietary PolyXen platform technology with the goal of having a once weekly or less frequent dosing, thereby making it the longest acting hemophilia A factor replacement treatment in development in the $9.3 billion global hemophilia market,” Maguire said.

Xenetic’s proprietary PolyXen is a platform technology developed for creating next-gen protein therapies by attaching polysialic acid (PSA), a biodegradable polymer found in living organisms, to existing proteins or peptides.

Attaching PSA to certain therapies may increase their apparent size while shielding the protein from degradation. The platform has been shown, in preclinical settings, to extend circulating half-life and to allow for an improved thermodynamic stability and resistance to proteases. To this date, other human trials have not found any evidence of PSA affecting immune responses in patients.

SHP656 uses the PolyXen platform technology to conjugate PSA to therapeutic blood-clotting factors, with the goal of improving its chemical metabolism and extending the active life of its biologic molecules.

Xenetic and Shire began this collaborative agreement, formerly known as Baxalta, in January 2014. Baxalta is responsible for funding the entire SHP 656 clinical program. Under the terms of the deal, Xenetic is entitled to up to $100 million in potential payments, contingent on the performance of certain milestones. This was the first one.

The two companies are also collaborating on the development of a novel series of polysialylated blood coagulation factors, including a next-gen factor VIII.