NCT07808151 · Solstice Oncology, Inc.
Neoadjuvant Pembrolizumab and Porustobart in Resectable pMMR/MSS Colon Cancer
What this study is about
The goal of this clinical trial is to learn if giving two medicines together, porustobart and pembrolizumab, before surgery can treat a common type of colon cancer called microsatellite stable (MSS) colon cancer in adults. This type of cancer can be removed with surgery and has not spread to other parts of the body. Both medicines work by helping the immune system fight cancer.
View original scientific description
The goal of this clinical trial is to learn if giving two medicines together, porustobart and pembrolizumab, before surgery can treat a common type of colon cancer called microsatellite stable (MSS) colon cancer in adults. This type of cancer can be removed with surgery and has not spread to other parts of the body. Both medicines work by helping the immune system fight cancer. The main questions this study wants to answer: How well do the medicines destroy the cancer before surgery? What side effects do participants have when taking the medicines? Researchers will compare two groups to see which treatment schedule works better and is safer. Both groups get pembrolizumab. One group gets one dose of porustobart (Day 1 only), and the other group gets two doses (Day 1 and Day 22).
Interventions
DRUG
Pembrolizumab
Administered to: Dose Schedule 1 - Porustobart + Pembrolizumab, Dose Schedule 2 - Porustobart + Pembrolizumab
DRUG
Porustobart
Administered to: Dose Schedule 1 - Porustobart + Pembrolizumab, Dose Schedule 2 - Porustobart + Pembrolizumab
Primary outcome measures
Major Pathologic Response (MPR) rate by Blinded Independent Pathologic Review (BIPR)
Time frame: Assessed from surgical resection specimen (surgery occurs Day 42-Day 63, i.e., approximately Week 6-Week 9 after first dose)
MPR is defined as the proportion of patients with ≤10% residual tumor volume in the primary tumor and lymph nodes, as evaluated by BIPR, per treatment arm
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- ≥18 years of age at consent Adenocarcinoma of the colon (rectosigmoid considered non-rectal); pMMR/MSS status Any T3 or T4, N any, M0; disease amenable to surgical resection ECOG Performance Status 0-1 Adequate tumor tissue sample with associated pathology report Adequate hematologic, hepatic, and renal function Reproductive status/contraception requirements per protocol
Exclusion criteria
- Investigational agent within 3 weeks of first dose Imminent or urgent need for surgery Prior treatment with ICIs targeting CTLA-4, PD-1, or PD-L1 Systemic corticosteroid/immunosuppressive therapy within 1 week of first dose (exceptions apply) History of severe hypersensitivity to a fully human mAb; interstitial lung disease; pneumonitis requiring corticosteroids Active or history of autoimmune disease requiring systemic treatment within 2 years Major surgery within 4 weeks of first dose; active infection requiring treatment
Where
- Los Angeles, California
- Tampa, Florida
- Chicago, Illinois
- Baltimore, Maryland
- Boston, Massachusetts
- New York, New York
- Cleveland, Ohio
- Nashville, Tennessee
- Seattle, Washington
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Oct 22, 2026 · Source of record for eligibility and locations