Background: Despite the survival benefit with docetaxel in mCRPC,1,2 patients inevitably progress. Cabazitaxel, a novel taxane, improved survival in the TROPIC trial.3 A single-arm multicenter, open label trial has been established to provide early access to cabazitaxel.
Methods: Patients received intravenous cabazitaxel (25mg/m2) every 3 weeks and oral prednisone 10mg daily. Safety assessments were undertaken following each cabazitaxel cycle.
Results: Baseline characteristics - median age 70 years, 34% aged ≥ 75 years, 93% had ECOG PS of 0 or 1, 93% had bone metastases and 48% had disease progression during/within 3 months of their last docetaxel dose. Of the 86 patients enrolled: >50% have received at least 4 cycles of cabazitaxel, 50 are still undergoing treatment and 36 discontinued treatment predominantly due to disease progression (22 patients). G-CSF was administered at cycle one of cabazitaxel in 36 (41.9%) patients. Treatment-emergent adverse events (TEAE) considered related to the study drug were experienced by 77 (89.5%) patients. The table shows the frequency of TEAEs occurring in ≥5% of the safety population. There were 2 (2.3%) treatment-related deaths (acute renal failure, neutropenic colitis); 11 (12.8%) patients experienced a TEAE resulting in permanent, premature discontinuation of treatment.
Frequency of selected toxicities:
TROPIC cabazitaxel arm (n=378) Australian EAP (n=86)
All grades Grade ≥3 All grades Grade ≥3
Neutropenia 347 (94%) 303 (82%) 20 (23%) 17 (20%)
Febrile neutropenia - 28 (8%) - 9 (11%)
Anaemia 361 (97%) 39 (11%) 26 (30%) 7 (8%)
Diarrhoea 173 (47%) 23 (6%) 49 (57%) 7 (8%)
Fatigue 136 (37%) 18 (5%) 47 (52%) 4 (5%)
Conclusions: Rapid accrual is suggestive of a high unmet treatment need in this patient population. The toxicity profile of cabazitaxel appears to be similar to that observed in the TROPIC study. Funding: Sanofi Australia Pty Ltd.