Biocryst Places Hold on Leukemia Trial, Changes Development Plans

BioCryst announced it is voluntarily placing on hold its Phase IIb clinical trial of intravenous Fodosine in the treatment of patients with T-cell acute lymphoblastic leukemia (T-ALL) and lymphoma. Oral capsules of Fodosine are being studied in other trials, which will not be affected.

Recent stability results detected particulate matter in clinical batches of the intravenous formulation of Fodosine. Preliminary findings have suggested that the particulates are associated with the vial stoppers used in clinical packaging and may result from an interaction between a component of the stopper and a component of the drug solution.

Assay data do not suggest any decrease in the potency of the Fodosine active drug product. The proportion of study drug vials affected has not been ascertained, so BioCryst determined that it was appropriate to suspend all patient treatment with any intravenous formulation. BioCryst and Mundipharma, the company's partner in the development of Fodosine, are working together to identify the best path forward for this formulation.

In addition, a preliminary analysis of the data now available from the Phase IIa trial of Fodosine in the treatment of T-ALL suggests the response rates may be lower than previously reported at the Annual Meeting of the American Society of Hematology (ASH).

"As the study progressed toward the target number of 80 subjects treated, the response rate appears to have decreased from the 18 percent reported at ASH in December 2006," W. James Alexander, senior vice president of clinical and regulatory operations and chief medical officer, said. "While the company considers these results preliminary, we don't think the final response rate will be as high as 18 percent."

In response, the company has decided to focus on developing Fodosine for treating cutaneous T-cell lymphoma (CTCL), for this is the disease indication the company believes could provide the fastest route to marketing approval. The company has requested a special protocol assessment from the FDA to address the clinical design of the next trial in CTCL.