ASCO GU 2014 - CARE Genitourinary Cancer Faculty - SOGUG-CABASEM Trial

ASCO GU 2014 Abstract# 190. Phase II study of weekly cabazitaxel for "unfit" metastatic castration resistant prostate cancer patients progressing after docetaxel treatment: Preliminary toxicity analysis (SOGUG-CABASEM trial).
Miguel Angel Climent Duran et al.

Background: Docetaxel (D) is standard first-line chemotherapy in patients (pts) with metastatic castration-resistant prostate cancer (mCRPC). Cabazitaxel (C), a novel taxane developed to overcome D resistance, showed an overall survival improvement in second line CRPC in a three-weekly dose schedule. Its main toxicity is hematological, especially in unfit patients. We aimed to evaluate efficacy and safety of weekly C/pred. in "unfit" mCRPC previously treated with D. 

Results: To date 47 pts have been enrolled and data are available for 38. Median age was 72 (range 56 to 83), 20 (53%) pts had ECOG 2, 29 (83%) had bone metastases. Cycles administered: 124 (median: 3; range: 1 to 9) and 446 weekly administrations (median 11; range 1 to 35). Mean dose intensity was 94%. Most frequent toxicities of all grades as % of cycles were: asthenia (20%), anemia (50%), leukopenia (13%), thrombocytopenia (14%), diarrhea (9%), rash (6%), nauseas (5%), dysgeusia (7%), xerostomia (6%), anorexia (5%), hand-foot syndrome (5%), and neuropathy (2%). Grade 3: thrombocytopenia (10%), anemia (6%), neutropenia (1%), asthenia (3%), anorexia (1%), mucositis (1%), nausea (1%), and vomiting (1%). No grade 4 toxicities were reported. Three patients discontinued the study due to asthenia G3 (2) and mucositis G3 (1). No grade III/IV diarrhea or febrile neutropenia were observed.

Conclusions: Administration of weekly C (10 mg/m2) to unfit pts seems to be safe with no grade 3 or greater neutropenia, diarrhea, or febrile neutropenia reported. If activity is confirmed, weekly C may represent an attractive option for unfit pts with mCRPC progressing after D treatment.

This was an interesting abstract as one of the main limiting factors for more widespread use of cabazitaxel has been toxicity. Although data from the expanded access program and other more recent clinical experience suggests that the toxicity observed in SATURN might have been unnecessarily high, it is still exciting to see that this weekly regimen was well tolerated in an unfit population. Looking forward, the efficacy data will be important.
— CARE Genitourinary Cancer Faculty