From the Guidelines
Maintenance therapy with Keytruda (pembrolizumab) for metastatic endometrial cancer should continue until disease progression or unacceptable toxicity, with treatment often lasting up to 2 years (35 cycles) in clinical trials, as supported by the NRG-GY018 trial 1. The standard dosing regimen is 200 mg intravenously every 3 weeks or 400 mg every 6 weeks.
- For patients who achieve complete response, treatment may be discontinued after at least 24 weeks of therapy and at least two treatments beyond complete response.
- Treatment may be resumed for up to one additional year if disease recurs after stopping.
- Patients should be monitored regularly with imaging studies every 6-12 weeks and for immune-related adverse events throughout treatment. The rationale for this duration is based on the drug's mechanism as an immune checkpoint inhibitor that helps the immune system recognize and attack cancer cells, with clinical benefit potentially continuing even after discontinuation due to established immune memory against the tumor, as seen in the KEYNOTE-775 trial 1. Some key points to consider when making this decision include:
- The 2-year PFS rate was 61.4% (95% CI 46.3% to 73.4%) in the dostarlimab group and 15.7% (95% CI 7.2% to 27.0%) in the placebo group (HR for disease progression or death 0.28; 95% CI 0.16 to 0.50; p<0.001) in the RUBY trial 1.
- The 2-year OS rates were 71.3% (95% CI 64.5% to 77.1%) with dostarlimab and 56.0% (95% CI 48.9% to 62.5%) with placebo (HR for death 0.64; 95% CI 0.46 to 0.87; p=0.0021) in the RUBY trial 1.
- Grade ≥3 AEs occurred in 70.5% of patients in the dostarlimab group and 59.8% of patients in the placebo group, with the most common AEs (any grade) being nausea (53.9% and 45.9%), alopecia (53.5% and 50.0%), and fatigue (51.9% and 54.5%) in the RUBY trial 1.
From the Research
Maintenance Keytruda Metastatic Endometrial Cancer
- The duration of maintenance Keytruda (pembrolizumab) for metastatic endometrial cancer is not explicitly stated in the provided studies.
- However, according to the study 2, patients with previously treated, advanced microsatellite instability-high or mismatch repair-deficient (MSI-H/dMMR) tumors, including endometrial cancer, received pembrolizumab 200 mg once every 3 weeks for 35 cycles.
- In the study 3, patients were randomized to receive pembrolizumab or placebo plus paclitaxel-carboplatin followed by maintenance pembrolizumab or placebo for up to 24 months.
- The study 4 reports on real-world outcomes in patients with recurrent, advanced, or metastatic endometrial cancer treated with lenvatinib plus pembrolizumab, but does not specify the duration of maintenance therapy.
- The study 5 discusses the targeted treatment of advanced endometrial cancer with a focus on pembrolizumab, but does not provide information on the duration of maintenance therapy.
- The study 6 provides a general overview of the current treatment of metastatic endometrial cancer, but does not discuss maintenance Keytruda specifically.
Treatment Duration
- The treatment duration for pembrolizumab in metastatic endometrial cancer can vary depending on the patient's response to treatment and the specific treatment regimen being used, as seen in studies 2 and 3.
- Further research is needed to determine the optimal duration of maintenance Keytruda for metastatic endometrial cancer, as noted in studies 4, 3, and 5.
Keytruda Efficacy
- Pembrolizumab has demonstrated robust and durable antitumor activity and encouraging survival outcomes with manageable toxicity in patients with previously treated, advanced MSI-H/dMMR endometrial cancer, as reported in study 2.
- The combination of lenvatinib with pembrolizumab has shown promising results in the treatment of metastatic endometrial cancer, regardless of mismatch repair status, as seen in study 4.
- Pembrolizumab plus chemotherapy has improved clinical outcomes in patients with advanced or recurrent endometrial cancer, as reported in study 3.