Monoclonal Antibodies Show Promise in Cancer Treatment: New Research on Pembrolizumab Therapy

Strategic Insights -

Pembrolizumab, a PD-1 inhibitor, has shown potential in increasing tumor-infiltrating lymphocytes and promoting local tumor immunologic recruitment, according to a pilot study published in Gynecologic Oncology Reports. The study, conducted by researchers at the Duke Cancer Institute, assessed the feasibility, toxicity, and changes in immune parameters in response to one dose of pembrolizumab in patients newly diagnosed with mullerian epithelial cancers.

Key Takeaways:

  • The pilot study enrolled 15 patients who received a single dose of pembrolizumab 200 mg IV, prior to standard therapy, including adjuvant chemotherapy.
  • Tumor infiltrating lymphocytes (TIL) levels changed in 4 of 11 paired sets, with 3 decreasing and 1 increasing post-treatment.
  • PD-L1 modified proportion score increased in 7 cases, decreased in 2, and remained unchanged in 2, with 8 of 10 assessable tumor pairs demonstrating either an increase or switch to positive.
  • Circulating CXCL10 and TNFa levels increased after pembrolizumab in patients with response, but decreased in the one patient with progression on adjuvant chemotherapy.
  • Digital spatial profiling showed increased IDO1 protein expression in immune and tumor compartments after treatment.
  • The study suggests potential for local tumor immunologic recruitment and increases in systemic inflammation, measured by cytokine production and differential IDO1 expression.
  • The researchers concluded that a single dose of pembrolizumab increased PD-L1 modified proportion score and/or stromal interface immune cells, suggesting potential for further investigation.

Statistics:

  • 15 patients enrolled in the pilot study.
  • 11 paired sets of tumor samples were evaluated for changes in TIL levels.
  • 8 of 10 assessable tumor pairs demonstrated either an increase in PD-L1 modified proportion score or the stromal interface switched from negative to positive.
  • 4 of 11 paired sets of tumor samples showed a decrease in TIL levels post-treatment.
  • 7 cases showed an increase in PD-L1 modified proportion score post-treatment.

Sources:

  • NewsRx. Researchers from Duke Cancer Institute Discuss Research in Monoclonal Antibodies (A pilot study investigating the effect of pembrolizumab on the tumoral immunoprofile of newly diagnosed mullerian cancers). Immunotherapy Weekly. June 18, 2025; p 4360.
  • Gynecologic Oncology Reports. A pilot study investigating the effect of pembrolizumab on the tumoral immunoprofile of newly diagnosed mullerian cancers. 2025,59():101770. (https://doi-org.sdpl.idm.oclc.org/10.1016/j.gore.2025.101770)
  • Elsevier. Gynecologic Oncology Reports. (http://www.journals.elsevier.com/gynecologic-oncology-reports/)