The trial is designed as an investigator-initiated, multicenter, prospective, single arm phase II study in patients with stage I-III dMMR CC scheduled for intended curative surgery to determine the efficacy of immunotherapy using pembrolizumab in the neoadjuvant setting. Patients will receive one dose of pembrolizumab (dosage of 4mg/kg, maximum of 400mg) following diagnosis. After 3 weeks a re-evaluation (to assess tumor response) will be performed, followed by standard surgery for resection of the tumor. Surgery will therefore be performed within 3 to 5 weeks after the dose of pembrolizumab treatment. Following the surgical resection the patients may receive post-operative chemotherapy in accordance with the clinical decision. The patients will be followed as per the standard Danish guidelines with CT scans at 1 and 3 years after surgery.
The aim of this study is to evaluate the safety and efficacy of neoadjuvant treatment with pembrolizumab before colonic resection in patients with early-stage (I-III) deficient mismatch repair (dMMR) colon cancer (CC).