BioCryst hits another hurdle, delays trial for its one remaining clinical candidate

Just a few months after discontinuing its most advanced pipeline asset, BioCryst Pharmaceuticals is now delaying testing of its only remaining clinical candidate.

The oral factor D inhibitor, dubbed BCX10013, is designed to treat complement-mediated diseases. The small molecule medicine was being assessed in healthy volunteers in a phase 1 single ascending dose and multiple ascending dose program. Initial data showed greater than 97% suppression of the alternative pathway of the complement system a day after one 110 mg dose, and that BCX10013 was safe and generally well-tolerated.  

However, recent dose-related observations in an ongoing, nonclinical study of BCX10013 have triggered the company to delay the clinical program, according to a fourth-quarter earnings report that was shared before market open Tuesday.   

It's still too early to say how the delay will impact the trial, a BioCryst spokesperson told Fierce Biotech in an email. The company did not provide any further details about the possible safety signal in the nonclinical trial.

The company’s stock fell from $10.20 Friday at market close to $8.64 per share on Tuesday. However, value is steadily climbing again, hitting $9.44 today at 10:30 a.m. ET.

The delay comes after the company axed a separate oral factor D inhibitor, dubbed BCX9930, in December 2022. The decision to abandon BCX9930 came after competitors shared data at the American Society of Hematology annual meeting in diseases like paroxysmal nocturnal hemoglobinuria (PNH) and C3 glomerulopathy.

“With the new competitor efficacy data presented at ASH, and the limitations preventing us from optimizing the dosing of BCX9930 for increased efficacy, it is unlikely that BCX9930 could meet the new standard-of-care,” BioCryst CEO Jon Stonehouse said in a Dec. 15 release.

At the time, BCX9930 was BioCryst’s most advanced candidate, with two mid-phase studies underway in PNH as well as a third phase 2 in kidney diseases. The asset had also been previously subject to a partial clinical hold from the FDA, though it was lifted after a revised protocol brought down dosing.

That discontinuation was intended to have a positive near-term financial impact and help shift focus to BCX10013, the company said at the time. Just one month earlier, the North Carolina-based biotech had said it would zoom in on BCX10013 and BCX9930 while abandoning an ultra-rare bone disease therapy known as BCX9250.

BioCryst now says it is exploring oral medicines directed at other targets across the classical, lectin and terminal pathways of the complement system.

The biotech, which holds on to approved hereditary angioedema drug Orladeyo and flu antiviral therapy Rapivab, ended 2022 with $270.8 million in total revenue, compared to $157.2 million in 2021. The increase was primarily due to $251.6 million from Orladeyo, according to the company.

The company said it expects Orladeyo to bring in global net revenue of at least $320 million in 2023, a factor that leads Evercore analysts to write that the drug is a strong business in itself.