|The following article features coverage from the American Society of Clinical Oncology 2020 meeting. Click here to read more of Cancer Therapy Advisor‘s conference coverage.|
Final results from the phase 2 KEYNOTE-100 trial confirm that single-agent pembrolizumab had modest antitumor activity in patients with recurrent advanced ovarian cancer, according to results presented during the ASCO20 Virtual Scientific Program.
Patients with higher PD-L1 expression appeared to have better overall response rates, according to Ursula Matulonis, MD, of Dana-Farber Cancer Institute in Boston, Massachusetts, who presented the results.
According to her presentation, results from KEYNOTE-028 (ClinicalTrials.gov Identifier: NCT02054806) showed that pembrolizumab resulted in an overall response rate of 11.5% in patients with PD-L1 positive recurrent ovarian cancer. These results prompted initiation of KEYNOTE-100 (ClinicalTrials.gov Identifier: NCT02674061).
The study enrolled patients with epithelial, fallopian tube, or primary peritoneal cancer with confirmed recurrence after front-line platinum-based therapy. Cohort A (285 patients) had received 2 or fewer prior lines of therapy and had a platinum-free or treatment-free interval of at least 3 months. Cohort B (91 patients) had received 3 to 5 prior lines of therapy and had a platinum-free or treatment-free interval of at least 3 months.
All patients received pembrolizumab 200 mg every 3 weeks for 2 years or until progression, death, or unacceptable toxicity.
An interim analysis of KEYNOTE-100 showed modest clinical activity in patients with recurrent advanced ovarian cancer after a follow-up of 18.3 months. The overall response rate was 8.0% at that time.
At the final analysis with a median follow-up of 37.8 months, the overall response rate was 8.1% in cohort A and 9.9% in cohort B. For both cohorts combined, the overall response rate was 8.5%.
Among patients with combined positive score of 10 or greater, the overall response rate was 11.6% in cohort A and 18.2% in cohort B. For cohorts A and B combined, those with higher PD-L1 expression had an overall response rate of 13.8%.
The median duration of response was 8.3 months in cohort A and 23.6 months in cohort B. For all-comers, the median duration of response was 10.2 months. According to Dr Matulonis, 67.7% of responses lasted 6 months or longer. Median progression-free survival was 2.1 months in both cohorts.
Overall survival was 18.7 months in cohort A and 17.6 months in cohort B. Among patients with higher PD-L1 expression, overall survival was 21.9 months in cohort A and 24.0 months in cohort B.
About 5% of patients discontinued treatment because of treatment-related adverse events. The researchers reported 2 treatment-related deaths. Immune-mediated adverse events occurred in 23.7% of patients.
Read more of Cancer Therapy Advisor‘s coverage of the ASCO 2020 meeting by visiting the conference page.
Matulonis UA, Shapira R, Santin A, et al. Final results from the KEYNOTE-100 trial of pembrolizumab in patients with advanced recurrent ovarian cancer. Presented at: ASCO20 Virtual Scientific Program. J Clin Oncol. 2020;38(suppl):abstr 6005.