Dr Kato on the Clinical Implications of the MONSTAR-Screen-3 Study in Resectable RCC

“Limited data are available in RCC regarding MRD surveillance. If you can check for MRD in RCC, we can use adjuvant pembrolizumab for ctDNA-positive patients and [avoid] adjuvant pembrolizumab for ctDNA-negative patients [to] avoid unnecessary adjuvant therapy. We are expanding this cohort. As of September 2025, we enrolled 29 patients and we are now expanding the cohort to 50 patients. [We plan to] present updated data at the next ASCO GU [meeting].”

Taigo Kato, MD, PhD, an assistant professor in the Department of Urology the Osaka University Graduate School of Medicine, discussed the clinical implications of the prospective MONSTAR-SCREEN-3 study (UMIN000053975) for the use of whole genome sequencing-based minimal residual disease (MRD) assays in resectable renal cell carcinoma (RCC), as well as next steps for this research.

Findings from MONSTAR-SCREEN-3 presented by Kato during the 2026 Genitourinary Cancers Symposium (ASCO GU) demonstrated that a whole genome sequencing approach to MRD surveillance in patients with RCC (n = 29) produced a baseline sensitivity rate of 100% at 1-month after surgery. The MRD positivity rate was 11.1% at this time point and 50.0% of positive cased were detected at ultra-sensitive levels. Circulating tumor DNA (ctDNA) levels were also found to be associated with tumor stage, size, and nodal status.

Kato explained that although limited data are available in terms of the clinical utility of minimal residual disease monitoring in RCC, it could potentially be used to inform adjuvant treatment decisions. Adjuvant therapies such as pembrolizumab (Keytruda) could be reserved for patients with ctDNA positivity and avoided in those with ctDNA negativity to avoid overtreatment in the adjuvant setting, he explained.

Kato added that investigators plan to expand the RCC cohort in MONSTAR-SCREEN-3 from 29 to 50 patients. Data from the expanded cohort will be presented at next year’s ASCO GU, he concluded.

Disclosures: Kato received honoraria from Bristol-Myers Squibb Japan; Merck; MSD; Pfizer; Takeda. He also received research funding from Takeda.