PT  - JOURNAL ARTICLE
AU  - Kim, Yoo-Na
AU  - Park, Boram
AU  - Kim, Jae Weon
AU  - Kim, Byoung Gie
AU  - Kim, Sang Wun
AU  - Kim, Hee Seung
AU  - Choi, Chel Hun
AU  - Lim, Myong Cheol
AU  - Ngoi, Natalie Yl
AU  - Tan, David Sp
AU  - Lee, Jung-Yun
TI  - 1348 Translational biomarkers of response to triplet maintenance in BRCA wildtype recurrent ovarian cancer: OPEB-01/APGOT-OV4
AID  - 10.1136/ijgc-2024-ESGO.836
DP  - 2024 Mar 01
TA  - International Journal of Gynecologic Cancer
PG  - A426--A426
VI  - 34
IP  - Suppl 1
4099  - http://ijgc.bmj.com/content/34/Suppl_1/A426.1.short
4100  - http://ijgc.bmj.com/content/34/Suppl_1/A426.1.full
SO  - Int J Gynecol Cancer2024 Mar 01; 34
AB  - Introduction/Background OPEB-01/APGOT-OV4 was a phase II clinical trial that investigated the efficacy and safety of triplet maintenance (olaparib, pembrolizumab, and bevacizumab) in BRCA wildtype, platinum-sensitive recurrent ovarian cancer. Here, we report the impact of biomarker status (PD-L1 and HRD status) on therapeutic outcomes.Methodology Patients showing a complete or partial response after second-line platinum-based chemotherapy were eligible. The primary endpoint was the 6 months progression-free survival (PFS) rate, with secondary endpoints including PFS, overall survival (OS), and safety. As pre-specified exploratory analysis, biomarkers such as PD-L1 and HRD were investigated.Results The primary endpoint was met, with 6 months PFS rate of 88.6% (95% CI 69.3–92.0). The median PFS was 22.4 months (20.4–∞), and the 12-months PFS rate of 84.0% (95% CI 69.3–92.0), indicating durable responses. Patient demographics were not different with respect to PD-L1 or HRD status. Out of 43 patients with available PD-L1 status, 28 patients had PD-L1 positive tumors (combined positive score [CPS] ≥ 1), while 15 had PD-L1 negative tumors (CPS <1). PD-L1 positive patients exhibited significantly better PFS and OS compared to the PD-L1 negative patients. Median PFS were 18.6 months (16.3 to ∞) in the PD-L1 negative and not reached (27.7 to ∞) in the PD-L1 positive group (p=0.0008). Out of 42 patients with available HRD status, 24 patients were HRD positive and 18 were negative. HRD positive patients exhibited significantly better PFS compared to the HRD negative patients. Median PFS were 27.7 months (21.2 to ∞) in the HRD positive and 21.8 (17.1 to ∞) in the HRD negative group (p=0.043).Conclusion PD-L1 positive and HRD positive status were each associated with a superior response to triplet maintenance therapy.Disclosures None.Abstract 1348 Figure 1