Spectrum Pharmaceuticals Incs' co-development partner, GPC Biotech AG has opened for accrual a Phase 2 study evaluating the company's lead drug candidate, satraplatin, in patients with metastatic breast cancer who have received no more than one prior chemotherapy treatment regimen.

The study is being managed by US Oncology. Satraplatin is currently in a Phase 3 registrational trial as a second-line chemotherapy treatment for patients with hormone- refractory prostate cancer. Spectrum's partner, GPC Biotech, is also opening new clinical studies to explore the potential of satraplatin in a number of additional tumour types.

The Phase 2 study in metastatic breast cancer is an open label, multicenter study being managed by US Oncology, a leading healthcare services network dedicated exclusively to cancer treatment and research. Fifty-seven research sites in the US Oncology Network plan to participate in this trial. The primary objective of this study is to determine the objective response rate of satraplatin in this patient population. The study is expected to enrol 80 patients, states a company release.

"Our partnership with GPC Biotech enables us to advance the development of satraplatin, while also minimising our expenses and preserving the upside associated with this promising drug for our company and our shareholders. While enrollment in the Phase 3 trial in hormone refractory prostate cancer is on target for completion by the end of the year, the initiation of additional, exploratory studies evaluating satraplatin in additional indications is another step towards realising the potential this drug might have on the treatment of cancer," stated Rajesh C. Shrotriya, chairman, chief executive officer and president

"Despite advancements in treating breast cancer, it is important to continue to find and develop effective therapies, as patients with advanced disease often do not respond to existing treatments or will eventually relapse. Satraplatin, as an oral drug that is relatively well tolerated, could provide an additional option for these patients. I look forward to exploring the compound's potential in this disease setting," said Joyce O'Shaughnessy, co-director of US Oncology's Breast Cancer Research Committee and director, Breast Cancer Prevention at Baylor- Charles A. Sammons Cancer Center in Dallas, Texas.

Satraplatin, an investigational drug, is a member of the platinum family of compounds.

Satraplatin is in a Phase 3 registrational trial - the SPARC trial, as a second-line chemotherapy treatment for hormone-refractory prostate cancer (HRPC). Spectrum's partner, GPC Biotech, has completed a Special Protocol Assessment with the US FDA and has received a scientific advice letter from the European regulatory authority, the European Medicines Agency (EMEA). The FDA has also granted fast track designation to satraplatin for this indication.

Breast cancer is the second leading cause of cancer-related death among women in the US and in Europe, behind lung cancer, according to the American Cancer Society. In 2005, it is estimated that over 210,000 new cases of invasive breast cancer will be diagnosed and over 40,000 women are expected to die from the disease in the US The numbers are even higher in the European Union, with an estimated 270,000 new cases of the disease diagnosed annually and 88,000 deaths.