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

Conditions

• Early Rectal Cancer
• Microsatellite Stable Rectal Carcinoma
• Stage I Rectal Cancer

Eligibility Criteria

Sex

ALL

Age

18 Years - N/A

Healthy Volunteers

Not accepted

Interventions

• Botensilimab — DRUG
  one IV infusion on Cycle 1 Day 1, over about 30 minutes
• Balstilimab — DRUG
  IV infusion every 2 weeks on Day 1 of each treatment cycle, over about 30 minutes, for up to 6 months

Study Details

This 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.

Key Dates

First listed

Jul 30, 2026

Start date

Sep 30, 2026

Status verified

Aug 2026

Primary completion

Jan 1, 2027

Completion

Dec 31, 2032

Study Design

Enrollment

16 participants (estimated)

Allocation

NA

Intervention model

SINGLE_GROUP

Primary purpose

TREATMENT

Arms

• Experimental: Botensilimab + Balstilimab
  Participants receive: * Botensilimab: one IV infusion on Cycle 1 Day 1, over about 30 minutes * Balstilimab: IV infusion every 2 weeks on Day 1 of each treatment cycle, over about 30 minutes, for up to 6 months The protocol specifies: * Botensilimab dose: 75 mg IV once * Balstilimab dose: 240 mg IV every 2 weeks for up to 6 months

Primary Outcome Measure

Complete response (cCR plus nCR with pCR at resection) within 6 months from initiation of therapy or nCR with pathologic complete response (pCR) with TES [ Time Frame: From baseline to 6 months from initiation of therapy ]

Central Contacts

• Benjamin Schlechter, MD
  617-632-4607
  [email protected]

Locations (3)

Find similar trials in Boston, MA

Related Studies

• A Study of Botensilimab and Balstilimab for Rectal Adenocarcinoma
  PHASE2 · Recruiting · Memorial Sloan Kettering Cancer Center · Basking Ridge, New Jersey