Complete response to therapy higher in clinical trial than real-world metastatic RCC patients

Among patients with metastatic renal cell carcinoma (RCC) who have received first-line therapies, complete response rates are lower in the real-world population than in the clinical trial population, reports a recent study. Complete response predicts a favourable overall survival.

In addition, several adverse clinicopathological features have occurred more frequently in the immuno-oncology‒based cohort than in the tyrosine kinase inhibitor (TKI) cohort among complete responders.

The investigators analysed response-evaluable patients who received frontline immuno-oncology‒based combination therapy or TKI monotherapy using the International Metastatic Renal Cell Carcinoma Database Consortium. They also compared the baseline characteristics of patients and postlandmark overall survival based on best overall response, as per RECIST 1.1.

Complete response was observed in 52 (4.6 percent) of 1,126 and 223 (3.0 percent) of 7,557 patients treated with immuno-oncology‒based and TKI therapies, respectively (p=0.005). Patients in the immuno-oncology‒based cohort who achieved complete response had an adjusted odds ratio of 1.56 (95 percent confidence interval [CI], 1.11‒2.17; p=0.009).

Among those who had a complete response, the immuno-oncology‒based group showed a greater proportion of nonclear cell histology (15.9 percent vs 4.7 percent; p=0.016), sarcomatoid dedifferentiation (29.8 percent vs 13.5 percent; p=0.014), as well as multiple metastases sites (80.4 percent vs 50.0 percent; p<0.001) than the TKI cohort.

Complete response independently correlated with postlandmark overall survival benefit in both cohorts, with adjusted hazard ratios of 0.17 (95 percent CI, 0.04‒0.72; p=0.016) and 0.28 (95 percent CI, 0.21‒0.38; p<0.001) for immuno-oncology‒based and TKI cohorts, respectively.