BioWorld International Correspondent

LONDON - Antisoma plc said a new independent statistical analysis of the Phase III trial of its lead compound, pemtumomab, predicts the study in ovarian cancer will not reach its completion point of 116 deaths until the second half of 2004. That means the company must do a licensing deal to fill the gap when current funding runs out at the end of 2003.

CEO Glyn Edwards told BioWorld International, "Fewer deaths, while good from a clinical point of view, is not so good from a financial point of view."

However, he added he is confident of securing a licensee before the end of 2002 for Therex, a treatment for breast cancer. "I'm sure we can raise enough to get us to the end of the pemtumomab study." In February, the company, based in London, raised £22 million (US$33.7 million) in a discounted rights issue.

The Phase III trial of pemtumomab, called SMART (Study of Monoclonal Antibody Radioimmuno-Therapy), compares survival of ovarian cancer patients receiving standard treatment plus pemtumomab to that of patients receiving standard treatment alone. Recruitment started in 1998 and is expected to reach the planned target of 420 patients later this year.

The product was previously expected to receive approval in 2002. However, in June 2001, the FDA told Antisoma to increase the number of patients in the trial, delaying the program by 18 to 24 months. Then in January, Antisoma renegotiated its licensing deal with Abbott Laboratories for pemtumomab, agreeing to take on an extra £9 million in development costs in return for higher milestone and royalty rates. Pemtumomab also is in Phase II for the treatment of gastric cancer.

Edwards said the new analysis of the likely completion date was good news because it gave Antisoma a firm date for which to plan. "In addition, there are doubters in the analyst community who said 2004 could extend to 2006. Now we have a definite indication that the trial will end in 2004."

Also last week, Antisoma announced it completed recruitment in a Phase I imaging trial of its radiolabeled monoclonal antibody fragment, TheraFab, in non-small-cell lung cancer. The aim of the study is to show how effectively TheraFab binds to tumor cells, and to check that it does not deliver unacceptable levels of radiation to healthy tissues.

Like pemtumomab, TheraFab is designed to bind to MUC1, a mucin cell membrane protein that is overexpressed in a variety of tumors of epithelial origin.