First patient dosed with Tesmilifene in pivotal breast cancer study

YM BioSciences Inc., the cancer drug development company, today announced that the first patient has been dosed in its 700 patient Phase III registration trial.

The international pivotal trial is designed to compare the overall survival differential resulting from the combination of YM's drug, tesmilifene, with the anthracycline, epirubicin, and cyclophosphamide against the use of epirubicin/cyclophosphamide alone in women with metastatic breast cancer. "We are very pleased to have commenced this important trial on time, and anticipate to have completed enrolment in approximately 18 months," said Mr. David Allan, Chairman and CEO of YM BioSciences.

Tesmilifene is a small molecule chemopotentiator. In the first Phase III trial, which enrolled 305 women, overall survival in women on the combination of tesmilifene with anthracycline (the standard of care in metastatic breast cancer) was greater than 50% longer than for women treated with the standard of care alone.

The drug has been clinically demonstrated to increase the effectiveness of the current principal chemotherapeutic drugs, anthracyclines and taxanes, which are used in the majority of cancers.

The current trial is to be conducted in 65 - 70 centers in North America and Europe. YM BioSciences may be able to submit the results for approval of the drug as early as mid 2006 as a result of the previously announced acceptance by the FDA for the application of "Sequential Analysis" to the patients in the trial. This process is designed to possibly significantly shorten the length of the trial if results similar to the first trial are evident. Dr. Katherine Pritchard, of Sunnybrook and Women's College Health Sciences Centre in Toronto, was recently announced as the North American Chair of the trial.