Introduction/Background*The primary objective of this multicentre, phase II study was to evaluate the preliminary efficacy of O (3000mg, IV q2W) in combination with D (1500mg, IV, q4W) in relapsed OC patients with the CD73 expression on intraepithelial inflammatory cells in the TME, defined by disease-control rate (DCR) at 16 weeks. Key eligibility criteria include: histologically confirmed OC with CD73 expression; relapsed disease; measurable disease; no prior immunotherapy; mandatory paired biopsy. 25 patients have been enrolled. Treatment was continued until disease progression, unacceptable toxicity, or withdrawal of consent. Primary endpoint is DCR; secondary endpoints include ORR, DoR, PFS, OS, safety and tolerability. Responses are also corelated to CD8 and PD-L1 positive expression in tumours. Assessment of PD-L1 (≥5%) and CD8 (≥5%) were performed by immunohistochemistry on archival tumour specimens. Clinical trial information: NCT03267589

Methodology The primary objective of this multicentre, phase II study was to evaluate the preliminary efficacy of O (3000mg, IV q2W) in combination with D (1500mg, IV, q4W) in relapsed OC patients with the CD73 expression on intraepithelial inflammatory cells in the TME, defined by disease-control rate (DCR) at 16 weeks. Key eligibility criteria include: histologically confirmed OC with CD73 expression; relapsed disease; measurable disease; no prior immunotherapy; mandatory paired biopsy. 25 patients have been enrolled. Treatment was continued until disease progression, unacceptable toxicity, or withdrawal of consent. Primary endpoint is DCR; secondary endpoints include ORR, DoR, PFS, OS, safety and tolerability. Responses are also corelated to CD8 and PD-L1 positive expression in tumours. Assessment of PD-L1 (≥5%) and CD8 (≥5%) were performed by immunohistochemistry on archival tumour specimens. Clinical trial information: NCT03267589

Result(s)*80% of patients had received ≥2 lines of therapy for relapse. DCR was 27%, median PFS was 2.7months and median OS was 8.4 months. 74% of patients were CD8-positive, 42% were PD-L1-positive, while 37% were both CD8 & PD-L1-positive. Biomarker positivity was not significantly associated with better DCR (p=0.584). TEAE: 1 thromboembolic event (grade 3), one neutropenia (grade 4), one cardiac arrest (grade5).

Conclusion*Combination of Oleclumab-durvalumab is feasible and demonstrate modest preliminary activity in relapsed OC. Further biomarker analysis research to predict response is ongoing.