100P - Phase II trial of tislelizumab plus bevacizumab and chemotherapy as the first-line therapy for persistent, recurrent, or metastatic cervical cancer: updated efficacy and safety results

Background

Patients (pts) with persistent, recurrent, or metastatic cervical cancer are at high risk of progression after first-line standard treatment with platinum-doublet chemotherapy ± bevacizumab. Adding a PD-1 inhibitor to this standard treatment improves the survival of PD-L1⁺ pts. The preliminary results showed that tislelizumab plus bevacizumab and platinum-based chemotherapy had a promising efficacy with unconfirmed ORR of 78.4% (29/37, 95% CI, 61.8%-90.2%), irrespective of PD-L1 expression status (J Zhu, et al., JCO 2023 41:16_suppl). Here, we presented the updated results based on the full efficacy analysis set.

Methods

Eligible pts with persistent, recurrent, or metastatic cervical cancer received tislelizumab (200 mg, Q3W) plus bevacizumab (7.5 mg/kg, Q3W) and platinum-based chemotherapy. PD-L1 expression was accessed using VENTANA PD-L1(SP263) assay. The primary endpoint was PFS. Secondary endpoints were ORR, DCR, DOR and safety.

Results

A total of 50 pts were enrolled, with 46 (92.0%) having squamous cell carcinoma. 41 pts were detected for PD-L1 expression; 35 (85.4%) pts were PD-L1⁺, 6 (14.6%) were PD-L1^–. As of 10 Aug 2023, the median follow-up was 7.8 months (range 0.8-14.6). Among 47 pts in the efficacy analysis set, the confirmed ORR was 72.3% (34/47, 95% CI 57.4%-84.4%), with CR rate of 14.9% (6/47). Subgroup analysis showed that ORR for pts with squamous cell carcinoma and adenocarcinoma were 72.7% (32/44) and 66.7% (2/3), respectively; ORR for pts with PD-L1⁺ and PD-L1^– tumors were 70.6% (24/34) and 100% (5/5), respectively. DCR was 100% (95% CI 92.4%-100.0%). Median DOR and PFS were not reached. After a median treatment duration of 6.8 months, grade ≥3 treatment-related adverse events occurred in 48.0% of pts. Immune-related adverse events (irAE) were reported in 32.0% of pts, with no grade ≥3 irAE reported. Serious adverse events occurred in 20.0% of pts.

Conclusions

The updated results further demonstrated the efficacy and tolerability of tislelizumab plus bevacizumab and chemotherapy, with increased CR rate observed during extended treatment duration.

Clinical trial identification

NCT05247619.

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.