Jérôme Meunier

Maintenance olaparib after platinum-based chemotherapy for advanced/metastatic endometrial cancer: GINECO randomized phase IIb UTOLA trial

Single-agent maintenance poly(ADP-ribose) polymerase (PARP) inhibition may represent an effective strategy in patients with advanced/metastatic endometrial cancer responding to platinum-based chemotherapy, including for molecular subtypes with suboptimal options. To explore this approach, we initiated the randomized phase IIb UTOLA trial (NCT03745950). Female patients without progression following front-line platinum-based chemotherapy for advanced/metastatic endometrial cancer were randomized 2:1 to twice-daily maintenance oral olaparib 300 mg or placebo until progression or intolerance, stratified by p53 status, mismatch repair status, and response to initial chemotherapy. The primary endpoint was progression-free survival (PFS) in the intention-to-treat population. Secondary endpoints were PFS in subgroups, time to second progression or death, time to first and second subsequent therapy, objective response rate, overall survival, patient-reported outcomes, and safety. In the intention-to-treat population (n = 145), there was no PFS difference between olaparib and placebo (median 5.6 vs. 4.0 months, respectively; hazard ratio 0.94, 95% confidence interval 0.65-1.35; p = 0.74). However, intriguing numerical PFS effects were observed in exploratory analyses of pre-specified subgroups (p53-abnormal, complete response to initial chemotherapy, chromosomal instability). There was no overall survival difference between treatments. Grade 3/4 adverse events occurred in 36% versus 10% of olaparib- versus placebo-treated patients and were consistent with the olaparib safety profile in other cancers. Maintenance olaparib did not improve PFS, but promising numerical effects in subsets of patients warrant prospective evaluation.

Unraveling the Tumor Microenvironment and PD-L1 Expression across Tissue Types in High-Grade Serous Ovarian Cancer in the NeoPembrOV/GINECO Phase II Randomized Trial

Abstract Purpose: To describe PD-L1 expression across tissue types and its associated tumor microenvironment and to investigate how it affects its predictive value for response to pembrolizumab in treatment-naïve patients with ovarian cancer included in the NeoPembrOV phase II trial (NCT03275506). Experimental Design: PD-L1 expression was assessed for 85 patients (56 on metastasis and 29 on tubo-ovary) using tumor proportion score (TPS) and immune cell (IC) score, considering positivity if ≥1% and high expression if ≥5%. RNA sequencing and multiplex immunofluorescence were conducted. The Australian Ovarian Cancer Study was used as an external validation cohort. Results: PD-L1 was primarily expressed by tumor cells in tubo-ovaries and by ICs in metastases. The IC score assessed on the metastases was associated with a longer progression-free survival in the pembrolizumab arm compared with the control arm. Compared with tubo-ovaries, metastases were enriched in T and B cells as well as in granzyme B (GZMB) CD8 cytotoxic T-cell signatures. In metastases, the IC score was associated with immune infiltration and overexpression of additional immune checkpoints, such as IDO1, LAG3, and ICOS, whereas TPS was associated with cell proliferation, immune infiltration, and IFN-γ pathways. In tubo-ovaries, TPS was associated with pathways linked to cell proliferation and antigen presentation but was depleted in activated immune pathways, and CD274 expression was correlated with hypoxia and PI3K/Akt/mTOR signaling. Conclusions: Distinct PD-L1 expression patterns across tissue types are associated with different biological pathways and tumor microenvironments in ovarian cancer, affecting PD-L1 predictive value. Our results provide novel insights into high-grade serous ovarian cancer biology for tailoring immunotherapy in patients with ovarian cancer.