Neoadjuvant botensilimab plus balstilimab in MMR proficient and deficient early-stage cancers: first results of the pan-cancer NEOASIS study

Published: 2025-04-29 11:33:12 ET AGEN

Myriam Chalabi, MD PhD

Medical Oncologist, Group Leader

Netherlands Cancer Institute, Amsterdam Institution Logo, if desired

Myriam Chalabi

I have the following relevant financial relationships to disclose: Advisory role: BMS, MSD, Roche, Agenus (paid to the institution) Grant/Research support: BMS, Roche, MSD, Agenus

dMMR: Mismatch repair deficient pMMR: mismatch rep air proficie nt

Several studies have demonstrated the remarkable potential of neoadjuvant immunotherapy across tumor types

Response to neoadjuvant IO associated with survival

Highest response rates in MMR-deficient colon cancers

MMR-deficiency also occurs in other solid tumors

Majority of tumors across cancers are MMR-proficient

Blank et al, NEJM 2024; Chalabi et al, ESMO 2024; Latham et al, JCO 2019

Next-generation CTLA-4i botensilimab (bot) & balstilimab (bal, anti PD-1) effective in a range of previously immune non-responsive tumors

pMMR mCRC, metastatic sarcoma, metastatic ovarian cancer

Does neoadjuvant bot/bal induce

responses in "immune cold" tumors?

Does the efficacy seen in dMMR CRC translate to dMMR tumors of other origins?

NEOASIS: a pan-cancer neoadjuvant trial for patients with solid tumors

Bullock et al, Nat Med 2024; Wilky et al, JCO 2025; Bockorny et al, Gyn Onc 2023

mCRC: metastatic colorectal cancer pMMR: MMR-proficient

dMMR: MMR-deficient

MMR-deficient cohorts

Investigator-initiated, non-randomized basket study

First 5 pts in each cohort (dMMR or pMMR) receive 25mg bot

Dose-escalation from 25 to 50mg allowed if ≤1 DLT in first 5

MMR-proficient cohorts

patients (IDMC)

If no more than 2 DLTs with 50mg bot  continue accrual in efficacy cohorts with 50mg

Dose limiting toxicity (DLTs) definition:

Any grade 5 event

Grade 4 event persisting ≥3 weeks

Any grade 3 event persisting ≥ 6 weeks

Any treatment related toxicity resulting in a delay of surgery >2 weeks

Disclaimer

Agenus Inc. published this content on April 29, 2025, and is solely responsible for the information contained herein. Distributed via Public Technologies (PUBT), unedited and unaltered, on April 29, 2025 at 15:32 UTC.