Maintenance Pembrolizumab Dosing Schedule

Evidence-Based Dosing Schedule

The National Comprehensive Cancer Network (NCCN) guidelines recommend that pembrolizumab be continued as maintenance therapy, with the directive to refer to the original study protocol for maintenance therapy dosing schedules, which is 400mg every 6 weeks for up to 14 maintenance cycles, as established in the NRG-GY018 trial (KEYNOTE-522) 1
The NRG-GY018 trial (KEYNOTE-522) used pembrolizumab 200mg every 3 weeks for 6 cycles during combination chemotherapy, followed by pembrolizumab 400mg every 6 weeks for up to 14 maintenance cycles, and this patient has completed the initial 6 cycles of combination therapy and should now be receiving 400mg every 6 weeks, not 200mg every 3 weeks 1

The combination of carboplatin/paclitaxel + pembrolizumab followed by pembrolizumab maintenance is Category 1 evidence for stage III-IV dedifferentiated endometrial carcinoma, according to the NCCN guidelines 1, 2
The Society for Immunotherapy of Cancer guidelines specifically reference the NRG-GY018 trial design with its transition to Q6W dosing for maintenance, which is appropriate for this patient's tumor characteristics (stage III, dedifferentiated histology, full-thickness myometrial invasion, serosal involvement) 1, 3

Grade 3-5 adverse events occurred in 63.3% of patients receiving pembrolizumab in the NRG-GY018 dMMR cohort and 55.1% in the pMMR cohort, with fatigue, peripheral neuropathy, anemia, and nausea being most common, and this patient has experienced a subclavian vein thrombus at her port site, which is a treatment-related complication but not a contraindication to continuing pembrolizumab 1

Change maintenance pembrolizumab from 200mg every 3 weeks to 400mg every 6 weeks to align with the NRG-GY018 protocol and NCCN guideline recommendations, and maintain the total planned duration of up to 14 maintenance cycles (as specified in NRG-GY018) 1
The NRG-GY018 trial protocol specified up to 14 cycles of maintenance pembrolizumab every 6 weeks following the initial 6 cycles with chemotherapy, and this patient's end of treatment date should be calculated based on 14 six-week cycles from the start of maintenance, not based on the current Q3W schedule 1