Article Text

Download PDFPDF

PR003/#357  Peripheral PD-1+regulatory T cells for predicting treatment response to parp inhibitor maintenance in patients with epithelial ovarian cancer
  1. Junsik Park1,
  2. Jung Chul Kim1,
  3. Yoo-Na Kim1,
  4. Yong Jae Lee1,
  5. Sunghoon Kim1,
  6. Sang Wun Kim1,
  7. Su-Hyung Park2 and
  8. Jung-Yun Lee1
  1. 1Yonsei University College of Medicine, Obstetrics and Gynecology, Seoul, Korea, Republic of
  2. 2Korea Advanced Institute of Science and Technology, Graduate School of Medical Science and Engineering, Daejeon, Korea, Republic of


Introduction Poly (adenosine diphosphate [ADP]-ribose) polymerase inhibitors (PARPis) are becoming the standard of care for epithelial ovarian cancer (EOC). Recently, clinical trials of triple maintenance therapy (PARPi+anti-angiogenic agent+anti-PD-1/L1) are actively ongoing. Here, we investigated the immunological effects of PARPi or triple maintenance therapy on T cells and their impact on clinical responses.

Methods We collected serial blood from EOC patients receiving PARPi therapy (cohort 1: PARPi, n=49; cohort 2: olaparib+bevacizumab+pembrolizumab, n=31). Peripheral T cells were analyzed using flow cytometry and compared according to the PARPi response. Progression-free survival (PFS) was assessed according to predictive biomarkers identified in a comparative analysis

Results Regulatory T cells (Tregs) were suppressed by PARPi therapy, whereas PD-1 was not significantly changed. Short PFS group exhibited a higher percentage of baseline PD-1+Tregs than long PFS group, and the patients with high percentage of PD-1+Tregs before treatment showed poor PFS in cohort 1. However, the expression of PD-1on Tregs significantly decreased after receiving triple maintenance therapy, and the reduction in PD-1+Tregs was associated with superior PFS in cohort 2 (P=0.0078).

Conclusion/Implications PARPi suppresses Tregs, but does not affect PD-1 expression. Addition of PD-1 blockade to PARPi decreases PD-1+Tregs, which have negative predictive value for PARPi monotherapy. Our data suggest that addition of PD-1 blockade to PARPi maintenance therapy is a promising option to improve survival outcomes for high-risk patients with ovarian cancer.

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.