522MO - Preliminary results of sintilimab (Sin)+bevacizumab (Bev) in recurrent/persistent ovarian clear cell carcinoma (INOVA): A multicenter, single-arm, phase II trial

Background

Recurrent ovarian clear cell carcinoma (OCCC) has an abysmal prognosis with only 6∼8% ORR in chemotherapy. Antiangiogenic therapy and immunotherapy might have potential efficacy in OCCC due to the unique clinicopathological characteristics, gene expression profile, and immune microenvironment. Moreover, anti-PD-1 + Bev has shown certain efficacy in renal clear cell carcinoma, which exhibits similar gene expression profiles to OCCC. Herein, we aim to investigate the potential benefit of Sintilimab (PD-1 antibody) + Bev combination therapy for recurrent/persistent OCCC patients.

Methods

This INOVA study followed Simon's 2-stage design. A total of 38 recurrent/persistent OCCC patients with at least one-line pretreated platinum-containing chemotherapy were planned to be recruited. Patients receive Sin (200mg iv. q3w) and Bev (15mg/kg iv. q3w) until disease progression or intolerable toxicity, up to 2 year and 22 cycles, respectively. The primary endpoint was investigator evaluated objective response rate (ORR) per RECIST 1.1. If more than 1 of 17 patients achieved objective response in stage 1, the study will enter stage 2.

Results

Between April 8, 2021 and April 25, 2022 (data cutoff), 23 patients had been enrolled, with median age of 58 (range,28-67) and 73.9% were Bev naive. All patients received prior platinum-containing chemotherapy. The median lines of treatment were 3 (range, 2-8). 18 of 22 patients (81.8%) were platinum-resistant relapsed. 20 patients were evaluable with at least one radiological evaluation after base line. 8 patients achieved objective response which inferred an ORR of 40.0% (1 CR, 7 PR; 95% CI, 19.1%-63.9%) and a DCR of 75.0% (8 OR, 7 SD; 95% CI, 50.9%-91.3%). Frequently occurring adverse events were grade 1-2, including proteinuria (33.3%), hypothyroidism (27.8%) and ALT, AST elevation (16.7%). Only one (5.6%) patient had a grade 3 immune myocarditis.

Conclusions

Sintilimab and bevacizumab combination therapy as a chemo-free regimen exhibites promising efficacy and favorable safety for recurrent/persistent OCCC patients. The trial is still recruiting, more data would be further analyzed and reported.

Clinical trial identification

NCT04735861.

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Beijing CSCO Clinical Oncology Research Foundation.

Disclosure

All authors have declared no conflicts of interest.