BioCryst Pharmaceuticals Inc. has initiated a pivotal trial of its lead oncology drug, Fodosine, in the treatment of patients with relapsed or refractory T-cell leukaemia/lymphoma.

Initiation of this trial triggers a $5 million event payment from Mundipharma International Holdings Ltd (Mundipharma) to BioCryst under the terms of the collaboration established in February, 2006 between the two companies to develop and commercialise Fodosine, in markets across Europe, Asia, Australia and certain neighbouring countries for use in oncology.

The multicenter, open-label, non-randomised, repeat-dose registration study will be conducted in accordance with a Special Protocol Assessment (SPA) agreement between the US Food and Drug Administration (FDA) and BioCryst and will test a combination of intravenous and oral formulations of Fodosine. Designed to determine the rate of complete remission achieved with this regimen of Fodosine, the multinational trial will include sites in the US, Eastern and Western Europe, and South America.

"This pivotal trial is based on the encouraging results we have seen in earlier studies of Fodosine, including the positive data reported recently at the 2006 American Society of Haematology Annual Meeting," said J Claude Bennett, MD, chief operating officer of BioCryst. "Those data indicated Fodosine is safe, well tolerated and effective as a single agent therapy and we believe Fodosine has the potential to be a valuable addition in the treatment of patients with T-cell mediated diseases."

Fodosine is a transition-state analog inhibitor of the target enzyme purine nucleoside phosphorylase (PNP). The drug is currently being studied in clinical trials for indications including T-cell leukaemia (T-ALL), cutaneous T-cell lymphoma (CTCL), B-cell acute lymphoblastic leukaemia (B-ALL) and chronic lymphocytic leukaemia (CLL).

"The initiation of this pivotal study represents a major advancement in the company's efforts to bring Fodosine to market," said Jon P Stonehouse, CEO of BioCryst. "There is a great need for new treatment options in T-cell mediated leukaemia's and lymphomas and we are working aggressively to enrol patients into this trial and advance this novel product toward commercialisation in collaboration with our partner, Mundipharma."

Under the terms of the partnership, Mundipharma has committed to fund 50 per cent of costs, up to $10 million, on current trials of Fodosine to be conducted by BioCryst, as well as an additional $15 million to assist in the evaluation of Fodosine's therapeutic safety and efficacy profile. Including the milestone reported today and as part of the original agreement with Mundipharma, BioCryst may receive future event payments totalling $155 million, along with royalties on product sales of Fodosine by Mundipharma. BioCryst retains all rights to commercialise and promote Fodosine in the United States, and other countries outside the scope of this agreement. BioCryst will owe sublicense payments to third parties on this event payment.