# A Study of Botensilimab and Balstilimab for the Treatment of Colorectal Cancer

Source: https://onco.cc/trials/nct05608044/  
OnCo record `nct05608044` (Trial). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

A phase 2 trial of Botensilimab in colorectal cancer, run by Agenus Inc., active and no longer recruiting.

## Summary

A Study of Botensilimab and Balstilimab for the Treatment of Colorectal Cancer is a phase 2 interventional study registered as NCT05608044 by Agenus Inc., with 234 participants enrolled, started 2022-11-30 and due to reach its primary completion in 2027-09. Interventions recorded: Botensilimab, Balstilimab, Standard of Care. Conditions listed: Metastatic Colorectal Cancer. No results are recorded here; the registry entry is the source.

## Fields

- Kind: Trial
- Status: active
- Last checked: 2026-09-16
- Also known as: BOT/BAL phase 1b/2 expansion
- Tags: ctgov-ingest
- Registry id: NCT05608044
- Phase: 2
- Setting: A Randomized, Open-Label, Phase 2 Study of Botensilimab (AGEN1181) as Monotherapy and in Combination With Balstilimab (AGEN2034) or Investigator's Choice Standard of Care (Regorafenib or Trifluridine and Tipiracil) for the Treatment of Refractory Metastatic Colorectal Cancer
- Sponsor: Agenus Inc.
- Enrolled: 234

## Notes

- Agenus's phase 2 of botensilimab, an Fc-enhanced anti-CTLA-4 antibody, with the PD-1 antibody balstilimab is the furthest any regimen has got in microsatellite-stable metastatic colorectal cancer without liver metastases. In the December 2025 data cut, 123 patients (median three previous lines, 67 percent with three or more) had an objective response rate of 21 percent (95% CI 14 to 29), median progression-free survival 4.0 months, median overall survival 21.2 months (95% CI 16.2 to 23.8) and 36-month overall survival 33 percent, with diarrhoea (39 percent, grade 3 or worse 8 percent) and fatigue the commonest treatment-related events. The result is uncontrolled and restricted to patients without active liver metastases, which is itself a favourable prognostic group, so it needs a randomised trial.

## Sources

- ClinicalTrials.gov NCT05608044: https://clinicaltrials.gov/study/NCT05608044
- Botensilimab plus balstilimab in previously treated microsatellite-stable metastatic colorectal cancer without liver metastases (Clinical Cancer Research 2026): https://doi.org/10.1158/1078-0432.CCR-26-1610

## Connected records

- cancers: [Colorectal cancer](https://onco.cc/cancers/colorectal/)
- technologies: [Immune checkpoint inhibitors](https://onco.cc/technologies/checkpoint-inhibitor/)
- drugs: [Balstilimab](https://onco.cc/drugs/balstilimab/), [Botensilimab](https://onco.cc/drugs/botensilimab/)
- companies: [Agenus](https://onco.cc/companies/agenus/)
- terms: [Hot vs cold tumours](https://onco.cc/terms/cold-vs-hot/), [Microsatellite instability (MSI-H) / mismatch repair deficiency (dMMR)](https://onco.cc/terms/msi/)

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