Impact of pegfilgrastim as primary prophylaxis for metastatic castration-resistant prostate cancer patients undergoing cabazitaxel treatment: an open-label study in Japan.

Cabazitaxel is an efficacious treatment for patients with metastatic castration-resistant prostate cancer who have previously progressed on docetaxel, but febrile neutropenia during the first cycle is a frequent complication. Asian patients are at increased risk of febrile neutropenia. Although primary prophylaxis with granulocyte colony-stimulating factor can reduce the incidence, its efficacy has not been prospectively demonstrated in Japanese patients with cabazitaxel treatment.

PEGAZUS, a prospective, single-arm study conducted at eight clinical sites in Japan, enrolled 21 heavily pretreated patients with metastatic castration-resistant prostate cancer. Patients received cabazitaxel 25 mg/m2 every 3 weeks, up to 10 cycles. Oral prednisolone 10 mg was taken daily. Pegfilgrastim 3.6 mg was administered at least 24 h after the cabazitaxel infusion. The primary endpoint was the incidence of febrile neutropenia in the first cycle.

The median number of treatment cycles was seven. The relative dose intensity of cabazitaxel was 67.4% (range, 53.2-91.3%). Two of 21 patients (9.5%) experienced febrile neutropenia in the first cycle. This rate was lower than the rate (43%) previously observed without prophylactic granulocyte colony-stimulating factor in a similar patient population. Six patients showed a prostate-specific antigen response (28.6%). Three of four patients evaluable for tumor response had stable disease and one had progressive disease. Grade ≥3 diarrhea was not observed. Primary prophylaxis with granulocyte colony-stimulating factor significantly reduced the incidence of febrile neutropenia in this study.

Cabazitaxel plus granulocyte colony-stimulating factor is safe and effective for Japanese patients with metastatic castration-resistant prostate cancer who have previously progressed on docetaxel. Clinical trial registration: ClinicalTrials.gov (NCT02441894).

Japanese journal of clinical oncology. 2019 Apr 26 [Epub ahead of print]

Takeo Kosaka, Hiroji Uemura, Makoto Sumitomo, Kenichi Harada, Mikio Sugimoto, Narihiko Hayashi, Kazuhiro Yoshimura, Satoshi Fukasawa, Evelyne Ecstein-Fraisse, Yoshinori Sunaga, Mototsugu Oya

Department of Urology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan., Department of Urology/Renal Transplantation, Yokohama City University Medical Center, 4-57 Urafune, Minami-ku, Yokohama 232-0024, Japan., Department of Urology, Aichi Medical University Hospital, 1-1 Yazakokarimata, Nagakute, Aichi 480-1195, Japan., Department of Urology, Kobe University Hospital, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe, Hyogo 650-0017, Japan., Department of Urology, Kagawa University Hospital, 1750-1 Ikenobe, Miki Kita-gun, Kagawa 761-0793, Japan., Department of Urology, Yokohama City University Hospital, 3-9 Fukuura, Kanazawa-ku, Yokohama, Kanagawa 236-0004, Japan., Department of Urology, Kindai University Hospital, 377-2 Ohno-higashi, Osaka-Sayama, Osaka 589-8511, Japan., Department of Urology/Prostate Cancer, Chiba Cancer Center, 666-2 Nitona-cho, Chuo-ku, Chiba 260-0801, Japan., Medical Evidence Generation, Sanofi, 54 rue La Boétie, Paris 75008, France., Biostatistics Programming, Oncology, Sanofi, 640 Memorial Drive, Cambridge MA 02142, USA.