Final results of a phase II trial of prolgolimab with platinum-based therapy and bevacizumab in patients with advanced cervical cancer.

Abstract

5536 Background: Here we present the final results of single-arm phase II CAESURA (NCT03912402) study of prolgolimab (anti-PD-1 antibody) with platinum doublet and bevacizumab in subjects with advanced cervical cancer (CC). Methods: 58 patients (pts) with metastatic or recurrent/persistent CC with measurable disease received prolgolimab (3 mg/kg) Q3W together with paclitaxel, platinum drug (cis- or carboplatin) and bevacizumab for 6 cycles and then therapy with prolgolimab and bevacizumab until disease progression or toxicity. Objective response rate (ORR) was assessed by central radiology review per RECIST 1.1 (primary endpoint) and iRECIST criteria. CT scans were performed after 9 and 18 weeks of treatment and in case of suspicion on disease progression. Results: Distant metastases at screening had 42 pts, 16 had recurrent or persistent CC. The median age of pts was 48 [38; 58] years old. Squamous cell carcinoma was diagnosed in 50 of 58 subjects. PD-L1 CPS ≥ 1 (22C3) was found in 45 pts, CPS < 1 in 6 cases. ORR per RECIST 1.1 was 63.8% (37 of 58 pts) and included 2 complete, 35 partial responses. ORR per iRECIST was 70.7% (41 of 58 pts) with 2 complete and 39 partial responses. At the cut-off date (12 months) PFS (secondary endpoint) per RECIST 1.1 criteria counted 8.5 (95% CI 5.7; 10.9) months, per iRECIST criteria it reached 13.1 (95% CI 8.1; 13.6) months. Median overall survival was not reached. Any grade adverse events (AEs) occurred in 98% (57/58) of pts, of them in 69% (40/58) they were related to study treatment, including 12 cases of severe events (gr. 3 or higher). Immune-related AEs (irAEs) occurred in 38% (22/58) of pts. The most common irAEs were gr. 1–2 endocrine disorders (26%), including thyroid disorders and one case of gr. 2 adrenal insufficiency. Other important irAEs included 2 cases of enterocolitis (gr. 3 and 4), 1 case of dermatitis (gr. 3), several cases of gr. 2–3 transaminase elevation (9%). In 15 pts at least one component of study treatment was discontinued due to AE, of them 4 events were related to study treatment (including immune-related enterocolitis and adrenal insufficiency). Conclusions: Prolgolimab in combination with chemotherapy and bevacizumab demonstrated promising efficacy, known and acceptable safety profile in pts with advanced CC. Phase III placebo-controlled trial evaluating prolgolimab with chemotherapy and bevacizumab (NCT03912415) as first-line therapy option in subjects with CC is ongoing. Clinical trial information: NCT03912402 .