Cadonilimab for recurrent small cell neuroendocrine carcinoma of the cervix: a phase 2 study.

OBJECTIVE

Small cell neuroendocrine carcinoma is a rare, aggressive histologic sub-type of cervical cancer. Although a standard frontline regimen exists, no standard highly active agent is available for recurrent disease. Single-agent anti-programmed cell death 1 therapy has also failed to demonstrate efficacy in this population; however, dual immune checkpoint blockade of programmed cell death 1 and cytotoxic T-lymphocyte-associated protein 4 has shown promising activity in high-grade neuroendocrine neoplasms. Data specific to recurrent small cell neuroendocrine cervical cancer remain sparse. We examined the safety and efficacy of cadonilimab, a bispecific antibody targeting programmed cell death 1 and cytotoxic T-lymphocyte-associated protein 4, in recurrent or metastatic small cell neuroendocrine cervical cancer.

METHODS

This was a phase 2, open-label, single-arm study of cadonilimab monotherapy in patients with recurrent or metastatic high-grade small cell neuroendocrine cervical cancer. Eligible patients received 6 mg/kg of cadonilimab on days 1 and 15 of each 28-day treatment cycle for up to 24 months. The primary objective was to estimate the 6-month progression-free survival probability using Kaplan-Meier analysis. Progression-free survival was defined as the time from treatment initiation to disease progression or death from any cause.

RESULTS

Among 9 patients who initiated treatment, 8 were evaluable for efficacy. One patient remained progression-free at 6 months (probability 0.125, 95% confidence interval 0.02 to 0.78). The median progression-free survival for the efficacy cohort was 2.19 months (95% confidence interval 1.84 to not available). The objective response rate was 0% (95% confidence interval 0% to 37%). Two patients experienced stable disease lasting 9.4 and 16.2 weeks, resulting in a disease control rate of 25% (2/8; 95% confidence interval 3% to 65%). One patient (1/9, 11%) experienced grade 3 fatigue. No grade 4 or 5 adverse events occurred.

CONCLUSIONS

Cadonilimab monotherapy for recurrent or metastatic small cell neuroendocrine cervical cancer was safe; however, no objective responses were observed.