LONDON ¿ There was good news and bad from British Biotech with the announcement that E21R, a granulocyte macrophage-colony stimulating factor (GM-CSF) antagonist, will progress to Phase II in the treatment of acute myeloid leukemia (AML), but that BB-2827, an orally absorbed collagenase inhibitor in Phase I, has been dropped, along with BB-76163, an aminopeptidase inhibitor, which was in preclinical development.

Tony Weir, finance director, told BioWorld International, ¿Clearly, any product failure is disappointing, but it is better to stop sooner rather than later.¿ BB-2827 and BB-76163 were being developed jointly with the Swiss company Serono SA under a two-year R&D agreement signed in October 2000 to commercialize metalloenzyme inhibitors for the treatment of inflammatory diseases.

Weir said the agreement is ¿progressing well.¿ Several of Serono¿s novel targets have been screened against British Biotech¿s compounds and the deal will not be affected by the decision to scrap the two projects. BB-2827 entered Phase I trials in October 2000, but was dropped following the observation of toxicological side effects in long-term preclinical studies.

E21R is a modified form of GM-CSF that in preclinical studies caused apoptosis (programmed cell death) in leukemic cells from patients with AML. The Phase I study showed it was well tolerated with none of the toxic side effects of existing treatments.

The open-label Phase II study initially will involve 14 patients who have failed to respond to other treatments or have relapsed. Following review of the safety and response data from the first group of patients, the study will be expanded to a total of 35 patients.

E21R was discovered at the Hanson Centre for Cancer Research in Adelaide, Australia, and is being developed under an agreement with the licensee, BresaGen Ltd., of Adelaide.

British Biotech has paid a higher price than most for advancing compounds that eventually fail ¿ seven pivotal Phase III trials of marimastat, an oral anticancer treatment, have so far failed to meet their primary end point. It is now trying to capitalize on its in-depth expertise in late-stage clinical development acquired as a result of these costly failures. In the past year the company, based in Oxford, has brought in three products, including E21R, for clinical development.

¿There is more competition with pharma to license products at a later stage of development. But our skills in late-stage clinical development distinguish us as a biotech, and many other biotechs may prefer to find a partner for collaboration rather than a licensee.¿