Nivolumab Plus Docetaxel for Metastatic Castration-Resistant Prostate Cancer
Posted: Wednesday, March 24, 2021
Karim Fizazi, MD, PhD, of the Université Paris-Saclay, Villejuif, France, and colleagues conducted the phase II CheckMate 9KD trial, comparing the efficacy of nivolumab with rucaparib, docetaxel, or enzalutamide in men with metastatic castration-resistant prostate cancer. In the final analysis results on the nivolumab-plus-docetaxel group (arm B), presented at the virtual edition of the 2021 Genitourinary (GU) Cancers Symposium, this combination therapy showed “encouraging” clinical activity, supporting the ongoing phase III CheckMate 7DX trial (Abstract 12).
The investigators focused on 84 patients with metastatic castration-resistant prostate cancer. Individuals were required to be on androgen-deprivation therapy, had at most two prior novel antiandrogen therapies, and had received no prior chemotherapy. Participants were administered 360 mg of nivolumab and 75 mg/m2 of docetaxel with 5 mg of prednisone for up to 10 cycles. This regimen was followed by 480 mg of nivolumab until unacceptable toxicity or disease progression occurred.
The median follow-up was 15.2 months. Individuals with measurable disease (n = 45) were featured in this analysis. The median number of nivolumab doses was 11, and the median number of docetaxel cycles was 8. Of the 45 patients with measurable disease, 17 patients demonstrated a partial response, and 1 patient had a complete objective response. The objective response rate for these individuals was 40%, and it appeared to be similar between patients who did and did not undergo novel antiandrogen therapies. The median progression-free survival and overall survival were both 84 months.
Treatment-related adverse events of any grade affected 95.2% of patients, with fatigue (39.3%) being the most common. Diarrhea and alopecia affected 35.7% and 34.5% of individuals, respectively. Treatment-related adverse events of grade 3 to 4 were observed in 47.6% of patients, with neutropenia occurring in 16.7% of patients. In 29.8% of patients, these events led to treatment discontinuation. Immune-related events such as gastrointestinal and skin-related side effects were reported in 35.7% and 26.2% of participants, respectively.
Disclosure: For full disclosures of the study authors, visit coi.asco.org.