Unlike traditional chemotherapy, the EV+pembrolizumab combination is producing a "tail on the curve" in survival data. This indicates a significant minority of patients with metastatic bladder cancer are achieving durable, long-term responses—a phenomenon previously unseen and a paradigm shift for the disease.

The type of treatment inducing ctDNA clearance matters. Clearance from immunotherapy appears to be more permanent and strongly prognostic than clearance from chemotherapy, which can be transient. This suggests immunotherapy may achieve a more profound and lasting elimination of cancer cells versus cytotoxic agents.

In frontline clinical trials for KRAS G12C NSCLC, combining olomorasib with pembrolizumab alone yielded a 90% response rate in patients with >50% PD-L1 expression. This surpassed the 78% rate seen when chemotherapy was added, suggesting a more targeted approach may be superior for this specific biomarker-defined subgroup.

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.

After numerous failed trials suggested immunotherapy was ineffective in ovarian cancer, the KEYNOTE B96 study marks a turning point. Combining pembrolizumab with chemotherapy showed statistically significant improvements in both progression-free and overall survival in platinum-resistant patients, reviving the entire therapeutic class for this disease.

In a pivotal neoadjuvant trial of cemiplimab for CSCC, none of the 40 patients who achieved a pathologic complete response (path CR) had relapsed at long-term follow-up. This suggests that path CR can be used as a powerful early indicator of long-term disease control and potential cure.

Dr. Carbone argues that traditional metrics like median survival or response rate are less relevant for immunotherapies. The true measure of success is the percentage of patients alive at five or six years—the "tail of the curve"—as this indicates a durable, potentially curative, response.

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.

Data from KEYNOTE-671 and other trials show that even patients achieving a pathological complete response (PCR) after neoadjuvant chemo-IO have better outcomes with the full perioperative regimen. This challenges the idea of de-escalating adjuvant therapy based on surgical pathology alone.