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OncoMatch/Clinical Trials/NCT07735624

RECTIFY-1: Neoadjuvant Botensilimab + Balstilimab in MSS/pMMR Early Rectal Cancer

Is NCT07735624 recruiting? Yes, currently enrolling (Sep 2026). This Phase 2 trial studies multiple treatments including Botensilimab and Balstilimab for early rectal cancer.

Phase 2RecruitingDana-Farber Cancer InstituteNCT07735624Data as of Sep 2026

Treatment: Botensilimab · BalstilimabThis is a multi-site, prospective, non-randomized phase 2 study evaluating neoadjuvant botensilimab in combination with balstilimab for patients with microsatellite stable (MSS) / mismatch repair proficient (MMRp) early rectal cancer staged T1-T2 N0 by MRI and considered candidates for surgical resection without standard neoadjuvant therapies. Participants will receive a single IV dose of botensilimab on Day 1 followed by balstilimab IV every 2 weeks for up to 6 months, with tumor response assessments during treatment and follow-up afterward.

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Extracted eligibility criteria

Treatments studied

Immunotherapy

Balstilimab

Other

Botensilimab

Cancer type

Colorectal Cancer

Biomarker criteria

Required: Mismatch-repair proficient (pMMR / MSS)

Performance status

ECOG 0–1(Restricted strenuous activity)

Prior therapy

No prior treatment (treatment-naive required)
Max 0 prior lines

Cannot have received: anti-CTLA-4 therapy

Received prior anti-CTLA-4 or anti-PD-1/PD-L1 therapy and/or other experimental immunologic agents

Cannot have received: anti-PD-1 therapy

Received prior anti-CTLA-4 or anti-PD-1/PD-L1 therapy and/or other experimental immunologic agents

Cannot have received: anti-PD-L1 therapy

Received prior anti-CTLA-4 or anti-PD-1/PD-L1 therapy and/or other experimental immunologic agents

Cannot have received: experimental immunologic agent

Received prior anti-CTLA-4 or anti-PD-1/PD-L1 therapy and/or other experimental immunologic agents

Cannot have received: prior therapy for rectal cancer

Prior therapy for rectal cancer

Cannot have received: prior pelvic radiation therapy

Prior pelvic radiation therapy

Cannot have received: prior treatment for rectal cancer

Prior treatment for rectal cancer

Lab requirements

Blood counts

Neutrophils ≥ 1500/μL (Must be stable and off any growth factor within 4 weeks of first study treatment administration); Platelets ≥ 50× 10^3/μL; Hemoglobin ≥ 8.0 g/dL (transfusion to achieve this level is not permitted within 2 weeks of first study treatment administration)

Kidney function

Creatinine clearance ≥ 30 mL/min as measured or calculated per local institutional standards

Liver function

Aspartate aminotransferase/alanine aminotransferase ≤ 1.5 × upper limit of normal (ULN); Total bilirubin ≤ 1.5 × ULN (except patients with Gilbert syndrome who must have a total bilirubin level of ≤ 3.0 × ULN)

Adequate organ function defined as the following laboratory values within 7 days of Cycle 1 Day 1 (C1D1): Neutrophils ≥ 1500/μL ... Platelets ≥ 50× 10^3/μL ... Hemoglobin ≥ 8.0 g/dL ... Creatinine clearance ≥ 30 mL/min ... AST/ALT ≤ 1.5 × ULN ... Total bilirubin ≤ 1.5 × ULN (except patients with Gilbert syndrome who must have a total bilirubin level of ≤ 3.0 × ULN)

Structured fields extracted by AI. May contain errors — verify against the official protocol.

US trial sites

  • Brigham and Women's Hospital · Boston, Massachusetts
  • Dana-Farber Cancer Institute · Boston, Massachusetts
  • Beth Israel Deaconess Medical Center (BIDMC) · Boston, Massachusetts

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See all sites on ClinicalTrials.gov →

Frequently asked questions

Is NCT07735624 currently recruiting?

Yes, this trial is currently recruiting patients.

Can patients have received prior systemic therapy?

No. This trial requires treatment-naive patients — prior systemic therapy is an exclusion criterion.

Does this trial require MLH1?

Yes, MLH1 wild-type is a required biomarker for enrollment.

Does this trial require MSH2?

Yes, MSH2 wild-type is a required biomarker for enrollment.

Does this trial require MSH6?

Yes, MSH6 wild-type is a required biomarker for enrollment.

Could you qualify for this trial?

Enter your biomarker results to see how this trial's eligibility criteria match your specific cancer profile.

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