A pooled FDA analysis of four major kidney cancer trials found no "magic number" or threshold for tumor shrinkage that guarantees a favorable outcome. Instead, the relationship is linear: any incremental increase in tumor reduction correlates with better 36-month overall survival.

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The effectiveness of radioligand therapy is counterintuitive: as tumors shrink and PSMA binding sites decrease, less radiation is delivered to the cancer. The VISION trial showed the first two doses delivered more radiation to the tumor than the subsequent four, questioning the value of a fixed, prolonged treatment schedule.

Even in healthcare systems with universal free access, like the UK's NHS, the actual uptake of immunotherapy for metastatic kidney cancer is only about 60%. This real-world gap strengthens the argument for adjuvant therapy, as it ensures high-risk patients receive potentially life-saving treatment they might otherwise miss upon relapse.

The Rampart study's main contribution wasn't its specific drug data, but that it became the second positive trial in the adjuvant kidney cancer space. This balanced the 'scorecard' against multiple negative trials, reinforcing the general principle that early immune therapy is beneficial.

An FDA analysis showed the survival curve for kidney cancer patients on IO-IO therapy (ipinevo) is much flatter for those with early tumor growth compared to IO-TKI regimens. This suggests early progression on a dual-mechanism IO-TKI therapy indicates true resistance, while on IO-IO it could be delayed response.

The next frontier in CSCC isn't just about new drugs, but about optimizing existing ones. A key research area is determining the minimum number of immunotherapy doses required for an optimal response—potentially just one or two—to limit toxicity, reduce treatment burden, and personalize care for high-risk patients.

An overall survival (OS) benefit in an adjuvant trial may not be meaningful for patients in systems (e.g., the U.S.) with guaranteed access to the same effective immunotherapy upon recurrence. The crucial, unanswered question is whether treating micrometastatic disease is inherently superior to treating macroscopic disease later, a distinction current trial data doesn't clarify.

After immunotherapy, many colorectal cancer patients have residual nodules on scans that appear to be partial responses. However, ctDNA testing can confirm these are often just scar tissue, not active disease. This provides the confidence to stop therapy at the two-year mark and avoid unnecessary surgeries for what are effectively complete responses.

The failure of the Checkmate 914 adjuvant trial, which used a six-month duration of nivolumab plus ipilimumab, suggests this shorter treatment window may be inadequate. In contrast to positive trials with one year of therapy, this outcome indicates that treatment duration is a critical variable for achieving a disease-free survival benefit in the adjuvant RCC setting.

While depth of response strongly predicts survival for an individual patient, the FDA analysis concludes it cannot yet be used as a surrogate endpoint to replace overall survival in pivotal clinical trials. It serves as a measure of drug activity, similar to response rate, but is not sufficient for drug approval on its own.

Immunotherapies can be effective even without causing significant tumor shrinkage. Immunocore's drug KimTrack had a low 5-7% objective response rate (ORR) but demonstrated a massive overall survival (OS) benefit, challenging the reliance on traditional chemotherapy metrics for evaluating modern cancer treatments.