Abstract 1186
Background
Pegfilgrastim (PEG) is used for chemotherapy-induced febrile neutropenia (FN) prophylaxis. FN was observed in 54.5% of patients (pts) who received cabazitaxel (CBZ) 25 mg/m2 in a Japanese phase I study (NCT01324583). This phase 2 study assessed the efficacy and safety of prophylactic use of PEG in Japanese pts with metastatic castration-resistant prostate cancer (mCRPC) treated with CBZ plus prednisolone (P).
Methods
Pts previously treated with docetaxel received CBZ 25 mg/m2 Q3W + P 10 mg daily (maximum 10 cycles). PEG was administered on day 2 in the first and subsequent cycles. The primary endpoint was incidence of FN (absolute neutrophil count [ANC] 38.3 °C or sustained temperature of ≥ 38 °C for >1 h) in cycle 1. Decrease (≥50%) in PSA, time-to-PSA progression, and other safety parameters were assessed.
Results
Twenty-one pts (median age 70 years, ECOG-PS 0 or 1 [100%]) were enrolled; 61.9% had prior enzalutamide and 47.6% had prior abiraterone. The median number of cycles of treatment was 7.0; 9 (42.9%) pts completed 10 cycles; 9 (42.9%) discontinued because of disease progression and 3 (14.3%) discontinued because of adverse events. The median relative dose intensity for CBZ was 67.4%. Two (9.5%) pts presented with FN (95% confidence interval [CI], 1.17–30.38) in cycle 1 only. The median ANC nadir was 68.0/mm3 (range, 0–1740/mm3), median days to nadir was 8.0 (range, 7–9) and days to recovery was 4.0 (range, 3–9). Grade 3/4 treatment-emergent adverse events were observed in 21 (100%) pts (Table). There were no toxicity-related deaths. PSA response was observed in 6 (28.6%) pts (95% CI, 11.28–52.18) and the median time to PSA progression was 182 days (95% CI, 71–255).Table: 519P
Grade 3/4 treatment-emergent adverse events. Number of patients = 21.
Grade 3/4 TEAE (≥ 5%) | n (%) |
---|---|
Neutropenia | 20 (95.2) |
Thrombocytopenia | 5 (23.8) |
Leukopenia | 3 (14.3) |
Febrile neutropenia | 2 (9.5) |
Decreased appetite | 2 (9.5) |
Conclusions
CBZ plus P with prophylactic use of PEG was well tolerated in Japanese mCRPC pts.
Clinical trial identification
NCT 02441894.
Legal entity responsible for the study
Sanofi K. K.
Funding
Sanofi K. K.
Disclosure
H. Uemura: Consultancy fees from Janssen, Astellas, Takeda, Bayer, Daiichi Sankyo; lecture fees from AstraZeneca, Sanofi, Fujifilm, Kyowa Hakko Kirin, Kissei. M. Sumitomo: Consultancy fees from Sanofi, Janssen, Ono, Pfizer, Takeda, Kissei; lecture fees from Sanofi, Pfizer, Takeda, AstraZeneca; research funding from Ono, Sanofi, Astellas, AstraZeneca, Takeda. M. Sugimoto: Manuscript writing/editing fees from Janssen, Astellas, Takeda, AstraZeneca. E.B. Ecstein-Fraisse: Employee of Sanofi. Y. Sunaga: Stock ownership and employee of Sanofi. M. Oya: Consultancy fees from Astellas.; lecture fees from Astellas, Janssen, AstraZeneca, Sanofi, Takeda; research funding from Astellas, Takeda.
All other authors have declared no conflicts of interest.