Among men with metastatic, hormone refractory prostate cancer that has progressed after Taxotere® (docetaxel)-based chemotherapy, the investigational chemotherapy drug cabazitaxel may improve survival. The results of this Phase III clinical trial will be presented at the ASCO 2010 Genitourinary Cancers Symposium.

Prostate cancer is a hormonally sensitive disease that can be controlled for long periods with androgen deprivation therapy (ADT) or castration. When prostate cancer stops responding to this treatment is it referred to as hormone refractory prostate cancer. Because hormone refractory prostate cancer can be difficult to treat, new agents and treatment approaches continue to be evaluated.

Cabazitaxel is an investigational chemotherapy drug. To evaluate cabazitaxel in the treatment of metastatic, hormone refractory prostate cancer, researchers conducted a Phase III clinical trial (the TROPIC study) among 755 men in 26 countries. All of the study participants had experienced cancer progression in spite of Taxotere-based chemotherapy.

Study participants were assigned to receive treatment with either cabazitaxal plus prednisone or mitoxantrone plus prednisone.

• Median survival was 15.1 months among men treated with cabazitaxel compared with 12.7 months among men treated with mitoxantrone.
• Men treated with cabazitaxel also fared better in terms of progression-free survival and tumor response rates.
• Men treated with cabazitaxel were more likely than men treated with mitoxantrone to develop febrile neutropenia (low white blood cell count accompanied by fever).

In a prepared statement, the lead investigator on the study noted: “There are no effective treatments available to help men with metastatic castration-resistant prostate cancer whose disease continues to grow despite standard chemotherapy, and this large study shows an unequivocal survival benefit for patients who received cabazitaxel.”

Cabazitaxel has not yet been approved by the U.S. Food and Drug Administration (FDA). The results of this study will form the basis for a submission for FDA review.

Reference: Sartor AO, Oudard S, Ozguroglu M et al. Cabazitaxel or mitoxantrone with prednisone in patients with metastatic castration-resistant prostate cancer (mCRPC) previously treated with docetaxel: final results of a multinational phase III trial (TROPIC). Presented at the ASCO 2010 Genitourinary Cancers Symposium. March 5-7, 2010. San Francisco, CA. Abstract 9.