BioCryst Discontinues Mid-Stage Factor D Inhibitor

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BioCryst Pharmaceuticals is discontinuing the development of its twice-daily Factor D inhibitor BCX9930 after determining it is not likely to be commercially competitive in the paroxysmal nocturnal hemoglobinuria (PNH) market.

The company will shift its focus to the earlier-stage asset, BCX10013.

North Carolina-based BioCryst discussed the potential of BCX9930 at the American Society of Hematology meeting held this week.

BCX9930 was in development for the treatment of complement-mediated diseases, including PNH, C3 glomerulopathy, immunoglobulin A nephropathy and primary membranous nephropathy.

Safety data hamstrung BioCryst’s BCX9930, preventing higher dosing levels.

In April, the FDA placed a partial clinical hold on three clinical trials involving BCX9930 due to reports of elevated serum creatinine levels in PNH patients participating in the REDEEM trial. Those patients received twice-per-day 500 mg doses of BCX9930.

The FDA lifted the hold in August after BioCryst researchers determined a lower dose and adequate hydration would dilute the concentration of BCX9930 in the urine. The dilution would mitigate the formation of crystals associated with elevated serum creatinine levels, the company announced at the time.

Chief Executive Officer Jon Stonehouse said Thursday that an inability to increase the dosing levels of BCX9930 would likely hinder its competitive chances.

Chief Medical Officer Ryan Arnold echoed Stonehouse’s statements.

He said conversations at the conference helped inform the company’s decision to discontinue BCX9930 in favor of BCX10013, a once-per-day Factor D inhibitor with best-in-class potential.

Investigators and researchers at ASH suggested a once-per-day oral drug would be the best option for patients, Arnold said.

BioCryst anticipates BCX10013 will be assessed in multiple disease indications.

Stonehouse said that the relationships built with clinical testing sites during the development of BCX9930 will expedite future clinical plans for BCX10013. He added that some patients who participated in the BCX9930 trials could switch to BCX10013, which could speed up enrollment. 

Investors reacted negatively to the decision.

Shares of BioCryst fell nearly 6% in premarket trading Wednesday to $10.60. The stock closed at $11.17 at the end of the day.

A Competitive Space 

During ASH, several significant advancements in PNH were announced, including vital Phase III data from Novartis. The Swiss pharma giant reported its experimental drug, iptacopan, met the primary goal of achieving meaningful hemoglobin levels without transfusion.

That announcement, built on data announced in October, showed iptacopan demonstrated superiority against two AstraZeneca's PNH drugs, Soliris and Ultomiris.

In September, AstraZeneca posted positive interim results from a Phase III trial assessing danicopan, a complementary drug for Soliris and Ultomiris. The interim data showed danicopan significantly improved hemoglobin levels.