Initial Results from Checkmate 650, a Phase II Study of Nivolumab Plus Ipilimumab for the Treatment of Metastatic CRPC.

[tango65]

ASCO GU 2019: Initial Results from Checkmate 650, a Phase II Study of Nivolumab Plus Ipilimumab for the Treatment of Metastatic Castration-Resistant Prostate Cancer.

Low response rates (10% to 25%) and significant side effects (grade 3-5 adverse events in around 50% of the patients). It may work in cancers with specific mutations.

"In an exploratory biomarker subgroup analysis, overall response rates were higher in patients with greater PD-L1 mutational rate (>1%), DNA damage repair, homologous recombination deficiency or above mediation tumor mutation burden. Of the patients who had an objective response, these patients had tumors positive for BCRA2, FANCA, ERCC3, ATRX, XRCC2, and MLH1. In cohort 1, patients with higher PSA response was also correlated with greater PD-L1 mutational Rate (>1%), however, it was not associated with the response rate in cohort 2. Median overall survival was 19 months in cohort 1 and 15 months in cohort 2.

All grade treatment-related adverse effects were very common with rates >93% in both cohorts. Grade 3-5 adverse effects were present in 42% and 53% of patients in cohort 1 and 2, respectively. Most common high-grade AEs were primarily gastrointestinal."

urotoday.com/conference-hig...

[pjoshea13]

See also earlier study:

"Ipilimumab plus nivolumab and DNA-repair defects in AR-V7-expressing metastatic prostate cancer"

ncbi.nlm.nih.gov/pmc/articl...

-Patrick

[GP24]

cohort 1: asymptomatic or minimally symptomatic, who had progressed after at least 1 second generation hormone therapy with no prior chemotherapy;

cohort 2: progression after chemotherapy

There was no control group, therefore the adverse effects are similar in both groups. The mentioned side effects are severe:

Grade 3: Severe but not life threatening; hospitalization required; limitation of patient's ability to care for him/herself

Grade 4: Life threatening; urgent intervention required

Grade 5: Death related to adverse event