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).
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.
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 (%)|
|Febrile neutropenia||2 (9.5)|
|Decreased appetite||2 (9.5)|
CBZ plus P with prophylactic use of PEG was well tolerated in Japanese mCRPC pts.
Clinical trial identification
Legal entity responsible for the study
Sanofi K. K.
Sanofi K. K.
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.