Treatment-Free Survival Rates of VEGFR, ICB Therapies for mRCC

Patients with metastatic renal cell carcinoma (mRCC) who receive first-line immune checkpoint blockade (ICB) treatments may experience disease control without a need for ongoing systemic therapy.

New research presented at the 2024 American Society of Clinical Oncology Genitourinary Cancers Symposium by Mehul Gupta, MD, described treatment-free survival (TFS) rates after multiple first-line therapies.

Dr. Gupta and colleagues identified patients 3758 patients with mRCC using the International Metastatic Renal Cell Carcinoma Database Consortium (IMDC). The patients had undergone first-line systemic therapy with vascular endothelial growth factor receptor (VEGFR) regimens consisting of axitinib or envatinib-pembrolizumab, cabozantinib-nivolumab, or axitinib-avelumab, immune checkpoint blockade (ICB) doublet therapy with ipilimumab-nivolumab, or a combination ICB-VEGFR treatment. between February 2014 and February 2023.

By using differences in restricted mean survival time (RMST) over a period of 36 months, the overall survival (OS) from treatment initiation was divided into periods including TFS, time on first-line therapy, and survival after subsequent therapy initiation.

In this study, TFS was defined as the difference between the 36-month RMST between the time from treatment initiation to subsequent therapy initiation or discontinuation of therapy, death, or censor at last follow-up.

Of the 3758 patients included in the study, 2635 underwent first-line VEGFR monotherapy, 354 received ICB-VEGFR regimens, and 769 patients received doublet ICB. Patients who received VEGFR monotherapy and ICB-VEGFR regimens and favorable IMDC risk experienced a TFS duration of 8.5% and 10.1%, respectively. In intermediate/poor risk patients who were treated with VEGFR monotherapy, ICB-VEGFR regimens, and ICB doublet therapy, 5.9%, 10.3%, and 14.6% months of the 36-month period were spent alive and treatment-free, respectively.

Over the 36-month period, patients who received VEGFR monotherapy or ICB-VEGFR combinations experienced TFS for a maximum of 10% of the 36-month period, while IMDC intermediate/poor risk patients treated with ICB doublet therapy experienced a TFS period of 15%.