Investigators opened the CombiCoR‑Vax phase II trial testing a sequential combination of immunotherapy and chemotherapy in refractory microsatellite‑stable metastatic colorectal cancer (mCRC). The trial targets a population that typically shows limited benefit from checkpoint inhibitors; the protocol aims to prime the tumor microenvironment with chemotherapy before vaccine‑based immune stimulation. The study design and endpoints were detailed by trial sponsors and investigators, who hope the sequential strategy will convert cold tumors to immune‑responsive ones. Microsatellite‑stable (MSS) mCRC lacks the high mutational burden that predicts checkpoint response, hence alternative combinatorial strategies are under active study.