Merck KGaA’s acquisition from Taiho, Japan, of worldwide rights to the 22-year-old oral 5-FU drug UFT (tegafur-uracil) outside Asia could open up a substantial European market for the product in prostate cancer as well as colorectal disease and other cancers, especially among elderly patients.

The drug offers convenience, safety and tolerability advantages over intravenous 5-FU – the cornerstone of chemotherapy regimens in several cancers – so has potential to be the preferred option at least for older or very sick patients. While it offers no survival advantages, it spares patients from serious side effects, particularly hand-foot syndrome.

Data presented at the European Society of Medical Oncology (ESMO) meeting in Istanbul show UFT, given in combination with paclitaxel and estramustine, has promise as a treatment for hormone-refractory prostate cancer, especially among frail, elderly men. UFT, regarded as having roughly equal efficacy to intravenous 5-FU, was able to halve PSA (prostate specific antigen) levels – a measure of disease activity - in the 32-patient Phase II study.

Half of all evaluable patients achieved a biologic response, with a greater than 50% reduction in PSA by three months. At six months, half of the 10 evaluable patients had reduced their PSA level by 75%. With regard to tumour size, three had a complete response, one a partial response and one had achieved disease stability.

Olivier Fitoussi of Polyclinique Bordeaux-Nord Aquitaine, Bordeaux, France who led the Phase II study said chemotherapy treatment options for hormone-refractory prostate cancer are notoriously toxic so oncologists are keen to find less toxic alternatives for this population of usually elderly men.

“This study has produced terrific results so far in this difficult-to-treat population which tends to have considerable co-morbidities. The treatment was very well tolerated.” The study is continuing to recruit patients and further data will be published next year.

UFT with leucovorin (folinic acid) and radiotherapy is also proving an effective option for patients with locally advanced rectal cancer, according to Dr Enrique Casado of La Paz University Hospital, Madrid, Spain.

Speaking in Istanbul he said it produced tumour downstaging in up to 75% of cases studied and enabled more patients undergoing surgery to preserve their sphincter. Patients had an overall three-year survival of over 75%.

UFT is currently licensed in over 60 countries for use as a first-line treatment, in combination with leucovorin, for metastatic colorectal cancer. Outside Europe it is also approved for treatment of other solid tumours. In the past 20 years it has been used in more than 30 million cancer patients. UFT was licensed to Bristol-Myers Squibb in 1995 for development in markets outside Japan for treatment of mCRC and other GI cancers.

From Olwen Glynn Owen in Istanbul