Phase II study with lonidamine in the treatment of hormone-refractory prostatic cancer patients.

Twenty-one patients with metastatic prostate cancer who had become refractory to hormonal therapies received lonidamine (150 mg tid and 600 mg daily dose in 17 and 4 patients, respectively). In all but 4 patients, treatment was continued until disease progression or the development of severe toxicity. Toxicity was minimal and reversible (score 1 or 2) and included myalgia (8 cases), arthralgia (6 cases), gastrointestinal toxicity (11 cases), fatigue (14 cases) and testicular pain (9 cases). The response was evaluated after at least one month of therapy with lonidamine, according to NPCP-USA recommendations. Of 21 patients who entered the study, only 15 were evaluable for response; 2 died (1 for severe toxicity and 1 for drug-unrelated reasons). No objective response was obtained in the series. In fact, only 6 patients achieved stable disease and 9 progressed. Median survival time from the beginning of treatment was no longer than that of patients in a similar condition who were treated with standard palliative maneuvers. We conclude that this therapeutic approach with lonidamine is not active in hormone-refractory prostatic cancer patients with distant metastasis.