Immunotherapy with immune checkpoint inhibitors (ICI) has substantially
improved the treatment of advanced renal cell carcinoma (aRCC). Since
treatment effects vary among patients, identifying biomarkers to predict
response is crucial for optimizing clinical management. Expression of
programmed death ligand 1 (PD-L1) is associated with better response to
ICI treatment, but is not a valid biomarker. To advance patient
stratification for aRCC, we analyzed molecular and clinical data from
the JAVELIN Renal 101 (n=726) and IMmotion151 (n=823) trials, both of
which compared a combination of PD-L1 inhibitors and anti-angiogenic
treatments with sunitinib monotherapy. In JAVELIN Renal 101, we found
correlations between genes and progression-free survival (PFS) in
PD-L1-positive tumors treated with sunitinib. These associations were
independent of variations in the proportion of PD-L1-positive immune
cells present in the tumors. Clustering of PD-L1-positive tumors based
on PFS-related genes revealed an IMmune CHeckpoint Inhibitor-responsive
Phenotype (IMCHIP). In PD-L1-positive tumors with IMCHIP, combined
therapy with ICI led to significantly longer PFS relative to sunitinib
(13.3 months vs. 4.4 months median PFS), while in PD-L1-positive tumors
without IMCHIP, PFS was comparable for both treatments (11.1 months). By
de-correlating gene expression measurements from PD-L1 expression, the
clustering could be extended to PD-L1-negative tumors resulting in two
groups (aRCC1/2) that were independent of PD-L1 status. Stratification
based on aRCC1/2 and PD-L1 status allowed treatment effects to be
categorized into four groups. A significant difference in PFS between
treatments arms was only observed in patients with tumors of type
aRCC2/PD-L1-positive, which corresponded to the IMCHIP profile and
covered 32.4% of JAVELIN Renal 101. These findings could be validated in
the IMmotion151 trial, where IMCHIP represented 20% of the cohort.
Compared to other biomarkers currently being investigated, the
combination of aRCC1/2 with PD-L1 status exhibited the greatest
potential as a predictive biomarker for patient selection, which was
confirmed in both cohorts. The prognostic potential of the aRCC1/2
subdivision was evaluated in 476 clear cell RCC from TCGA. Here, aRCC2
was associated with significantly worse overall survival and
cancer-specific survival in both univariate and multivariable analyses,
accounting for age, sex, and clinicopathological parameters (TNM). In
summary, categorization into aRCC1/2 proved to be a new risk
stratification of aRCC which, in combination with PD-L1 status, enabled
the retrospective identification of responders who benefited from
combined therapy with ICI relative to sunitinib monotherapy. The
analysis of IMmotion151 trial data utilized data generated by
Genentech/Genentech Research and Early Development.