Platinum agent promising as second-line prostate cancer therapy

Key Points

Orlando, FL-Satraplatin, an investigational oral drug administered with prednisone, reduces the risk of disease progression in patients with advanced prostate cancer who have failed to respond to hormone treatment and chemotherapy by one-third, researchers reported at the third annual Prostate Cancer Symposium here.

"Currently, there is no FDA-approved second line treatment for hormone-resistant prostate cancer. Docetaxel is an approved first-line agent. So we opened the Satraplatin and Prednisone Against Refractory Cancer (SPARC) trial in 2003 to evaluate satraplatin compared to placebo."

In the phase III SPARC trial, a cohort of 950 patients with advanced prostate cancer participated. The men were randomly assigned to receive prednisone with either satraplatin or placebo. Patients in the satraplatin arm had a 33% reduction in the risk of disease progression compared with patients in the placebo arm, Dr. Petrylak, the study's lead author, reported.

Improvement in progression-free survival observed among patients receiving satraplatin and prednisone increased over time. At 6 months, the disease did not progress among 30% of the patients on the satraplatin and prednisone regimen, whereas 17% of those in the placebo group did not progress. At 12 months, 16% of the satraplatin plus prednisone group did not have disease progression, compared to 7% of patients in the placebo group.

One-third lower progression risk

"We looked at progression-free survival as the primary endpoint. We found there is a one-third less chance of progression if they received satraplatin compared to those who received placebo," Dr. Petrylak told Urology Times. "There was acceptable toxicity; less than 5% of patients had grade 3 or 4 non-hematologic toxicities. The most common toxicities were myelosuppression, such as thrombocytopenia; neutropenia; and gastrointestinal, such as nausea, vomiting, or diarrhea, which were generally mild to moderate.

"We are excited about the preliminary findings. Before, we did not have options for second-line treatment for prostate cancer. We hope that this drug will be approved by the FDA and, if it is, we will have a second-line agent for this disease."

A new drug application for satraplatin was submitted to the FDA earlier this year.

Dean Bajorin, MD, of Memorial Sloan-Kettering Cancer Center in New York, called SPARC a well-designed comparison study of satraplatin versus placebo.

Dr. Petrylak is a consultant/adviser to GPC Biotech, and Dr. Bajorin has served as a consultant to the company.