A modern strategy for localized MSI-high gastroesophageal cancer is to begin with dual immune checkpoint blockade. Clinicians can then perform an early response assessment and pivot to chemoimmunotherapy if the initial response is suboptimal, allowing for a flexible, response-adapted approach.

When choosing between therapies for dually positive (Claudin+/PD-L1+) gastric cancer, the existence of robust five-year survival data for immunotherapy regimens provides a compelling reason to prioritize it over newer agents like zolbetuximab, which lack such long-term follow-up.

While median survival improvements in advanced HCC are notable, the truly revolutionary impact of immunotherapy is the creation of a long-term survival "tail" on the Kaplan-Meier curve. Clinicians now manage patients for years, a reality that was nonexistent in the pre-IO era.

In the Keynote 522 trial for early-stage TNBC, adding pembrolizumab to chemotherapy resulted in only a modest improvement in pathological complete response (pCR). Surprisingly, this small initial gain translated into much more robust and significant long-term improvements in event-free and overall survival.

Experts favor a Nivolumab plus Ipilimumab (NIVO+EP) combination for newly diagnosed, MSI-high, stage IV gastroesophageal cancer patients who can tolerate it. This approach avoids chemotherapy and yields high, sustained response rates, including potential for complete pathologic responses in metastatic settings.

The ATTRACTION-6 trial surprisingly found that adding combination immunotherapy (ipilimumab + nivolumab) to first-line chemotherapy did not improve overall survival over chemotherapy alone in metastatic gastric cancer. This negative result reinforces that adding a single-agent checkpoint inhibitor to chemotherapy remains the global standard of care.

New targeted therapies are often approved only for first-line use. This forces clinicians into a difficult choice: using one effective drug like a checkpoint inhibitor means forfeiting the chance to use another, like zolbetuximab, in a subsequent line of treatment, thereby losing a valuable therapeutic option.

Data from trials like CheckMate 816 shows that achieving a Pathologic Complete Response (PCR) after neoadjuvant chemo-immunotherapy is a powerful early surrogate endpoint. Patients with PCR demonstrate markedly improved overall and event-free survival.

In the pivotal ECOG1910 trial, adding blinatumomab to frontline chemotherapy did more than just prevent relapse. It also improved non-relapse mortality, meaning it was a safer and more tolerable consolidation strategy than the chemotherapy alternative. This dual benefit drove its profound overall survival advantage.