Long-term Cadonilimab Data Suggest Durable Survival in Recurrent Cervical Cancer

Long-term survival data emerging for bispecific checkpoint therapies are helping clarify how next-generation immuno-oncology approaches may expand durable responses beyond traditional programmed cell death protein-1 (PD-1) or programmed cell death ligand-1 (PD-L1) inhibitors. Updated results from a pivotal Phase II study (COMPASSION-03/AK104-201) of cadonilimab, a PD-1/cytotoxic T lymphocyte associated antigen 4 (CTLA-4) bispecific antibody developed by Akeso, suggest that deep responses in recurrent or metastatic cervical cancer may translate into extended survival in heavily pretreated patients.¹

The findings, presented by Akeso during a late-breaking session at the 27th European Congress on Gynecological Oncology (ESGO 2026) in late February 2026, provide new long-term follow-up from the Phase II registrational trial evaluating cadonilimab monotherapy in patients with recurrent or metastatic cervical cancer who had progressed after platinum-containing chemotherapy.

The updated analysis reported a median follow-up of 26.5 months among 99 efficacy-evaluable patients and examined survival outcomes according to best overall response (BOR). Investigators reported that patients achieving complete responses demonstrated a 24-month overall survival (OS) rate of 100%, with median OS and progression-free survival (PFS) not yet reached.¹ Researchers said the findings reinforce the potential for dual-checkpoint targeting strategies to convert deep tumor responses into durable disease control.²

How do response depth and survival outcomes correlate in, as the trial?

Investigators conducted a BOR-stratified survival analysis to better understand how response depth influenced long-term outcomes. Among the group of patients who achieved a complete response (CR), median OS and median PFS were not reached. The 12-month PFS rate in this group reached 84.6%, while the median duration of response also remained unreached at the time of analysis, according to the company.¹

The group of patients who achieved partial response (PR) also showed extended survival outcomes. In this group, the median OS remained unreached, with a reported 24-month OS rate of 63%. Median PFS reached 11.17 months, with a 12-month PFS rate of 47.3%. Time to response was similar across response groups. Investigators reported a median time to response of 1.84 months for patients achieving CR and 1.87 months for those achieving PR.

Does cadonilimab demonstrate activity across PD-L1 expression levels?

The study population included a substantial proportion of difficult-to-treat patients, including those with PD-L1–negative tumors and those previously treated with multiple systemic therapies. More than 18% of participants had PD-L1 combined positive scores below 1, while 36% had received two or more prior lines of systemic therapy.

Across the overall study population, cadonilimab monotherapy produced a median OS of 17.5 months. Updated long-term follow-up showed 18-month and 24-month OS rates of 47.8% and 40.9%, respectively, with durable survival observed regardless of PD-L1 expression status.

The therapy’s differentiated activity profile reflects its dual targeting of PD-1 and CTLA-4 pathways, a strategy designed to enhance immune activation while potentially mitigating limitations associated with single-target checkpoint inhibition.

What role could bispecific checkpoint strategies play in next-generation immunotherapy?

Cadonilimab represents one of the first approved PD-1/CTLA-4 bispecific antibodies and has been evaluated across multiple tumor types. The agent is currently approved in China for recurrent or metastatic cervical cancer following platinum-based chemotherapy, as well as for first-line cervical and gastric cancers. The therapy is also under investigation in 11 ongoing Phase III or registrational studies, including global trials in gastric cancer and hepatocellular carcinoma.

Growing interest in multi-mechanism immunotherapy strategies is also reflected in other development programs. For example, Akeso is collaborating with INOVIO to evaluate cadonilimab in combination with DNA-encoded tumor antigen immunotherapy in glioblastoma within the INSIGhT adaptive platform trial. That program explores whether combining antigen-targeted immune priming with dual checkpoint blockade can improve responses in immunologically resistant tumors.³

Together, these programs illustrate how bispecific checkpoint platforms are increasingly being explored as foundational components of multimodal immunotherapy strategies aimed at improving durability of response across multiple cancer settings.⁴

References

1. Akeso. Cadonilimab Achieves 100% 24-Month OS in Complete Responders in R/M Cervical Cancer Based on Long-Term Phase II Results. Press Release. March 2, 2026
2. Zhao Y, Ma Y, Fan Y, et al. A multicenter, open-label phase Ib/II study of cadonilimab (anti PD-1 and CTLA-4 bispecific antibody) monotherapy in previously treated advanced non–small-cell lung cancer (AK104-202 study). Lung Cancer 2023;184:107355. doi: 10.1016/j.lungcan.2023.107355
3. INOVIO. INOVIO and Akeso Announce Clinical Collaboration to Advance Novel Combination Therapy for Glioblastoma (GBM). Press Release. March 4, 2026.
4. Zhang T, Lin Y, Gao Q. Bispecific antibodies targeting immunomodulatory checkpoints for cancer therapy. Cancer Biol. Med. 2023;20(3):181–95. doi: 10.20892/j.issn.2095-3941.2023.0002