Primary efficacy and safety results of BAT1308, a PD-1 inhibitor, + chemotherapy ± bevacizumab in phase 2 trial for persistent, recurrent, or metastatic cervical cancer.

Abstract

2611 Background: BAT1308 is a fully humanized and high-affinity anti-PD-1 IgG4κ antibody. Previous phase 1 study demonstrated BAT1308 had a promising efficacy in patients with advanced cervical cancer. Here we present the primary safety and efficacy results in phase 2 study for BAT1308 combined with platinum-based chemotherapy ± bevacizumab as first-line therapy for PD-L1–positive persistent, recurrent, or metastatic cervical cancer. Methods: In this multicenter, single-arm, open-label, phase 2 study, eligible patients were ≥18 to ≤75 years of age with PD-L1 CPS ≥1, FIGO Stage IVB cervical cancer, who did not receive prior systemic anti-tumor therapy for persistent, recurrent or metastatic cervical cancer and not amenable to curative treatment. Patients received BAT1308 (300 mg Q3W for up to 24 months) plus platinum-based chemotherapy (paclitaxel 175 mg/m 2 + cisplatin 50 mg/ m 2 or carboplatin AUC 5) and, per investigator discretion, bevacizumab (15 mg/kg). The primary endpoint was safety. The major secondary endpoint was objective response rate assessed by investigator according to RECIST 1.1. Results: As of January 7, 2025, a total of 29 patients were enrolled, with a median age of 53 years (range 32-69), 20 (69.0%) patients had ECOG performance status of 1, 15 (50.7%) patients with PD-L1 CPS ≥ 10, 24 (82.8%) patients had squamous-cell carcinoma, 17 (58.6%) patients received previous neoadjuvant or adjuvant chemotherapy or chemoradiotherapy with a paclitaxel + platinum regimen, 7 (24.1%) patients had previous untreated metastatic disease at trial entry. Bevacizumab was used by 23 (79.3%) patients in this phase II study. All 29 subjects received combination therapy. 27 subjects completed at least one efficacy assessment. The ORR was 74.1%, with a confirmed ORR of 70.4%. The complete response rate was 11.1%, and the disease control rate was 100%. Currently, 16 subjects remain on treatment. Among those who discontinued the study, 8 withdrew informed consent, 4 experienced disease progression, and 1 died. The 6-month, 9-month, and 12 -month PFS rates were 83.4%, 78.8%, and 78.8% respectively. The median PFS has not yet been reached. The most common adverse events were anemia (82.8%), white blood cell decreased (51.7%), alopecia (51.7%), thrombocytopenia (48.3%), and neutropenia (44.8%). Grade 3 and above adverse events occurred in 72.4% of 29 patients, and ≥ Grade 3 irAEs observed in 3 (10.3%) patients. Serious adverse events occurred in 44.8% of the patients. Conclusions: BAT1308 combined with platinum-based chemotherapy ± Bevacizumab as first-line therapy showed durable anti-tumor activity and manageable safety profile for PD-L1-positive (CPS ≥ 1) persistent, recurrent or metastatic cervical cancer. These data are consistent with the earlier results and provide support for further studies. Clinical trial information: NCT06123884 .