Individualizing renal cell carcinoma treatment through biomarkers discovery in the era of immune checkpoint inhibitors: where do we stand?

PURPOSE OF REVIEW

The treatment landscape of metastatic renal cell carcinoma has greatly evolved over the past fifteen years, leading to a significant improvement in the outcome of our patients. However, there is still an urgent need for predictive biomarkers that could guide our treatment selection, especially in the present era of immune-based treatments.

RECENT FINDINGS

A number of putative biomarkers of immunotherapy activity have been proposed over the past few years, including PD-L1 immunohistochemical expression, tumor mutational burden, neoantigens load, insertions and deletions, complex gene signatures, as well as lymphocytic subpopulations (either circulating or tumor-infiltrating). However, despite preliminary intriguing findings, no biomarker for immune checkpoint activity has emerged so far, that could be used in everyday clinical practice, mainly due to preliminary, or frankly, conflicting results.

SUMMARY

The quest for an 'ideal' biomarker, which should be characterized by adequate specificity, sensibility, predictive (and not just prognostic) value, robustness, reproducibility, ease of evaluation and low cost, is still ongoing.

Update on the most promising biomarkers of response to immune checkpoint inhibitors in clear cell renal cell carcinoma

In the last few years, the standard of care for metastatic clear cell renal cell carcinoma (mccRCC) has changed dramatically with the emergence of the immune checkpoint inhibitors (ICI): anti-PD(L)-1 used as a monotherapy or as in combination either with an anti CTLA-4 or with an anti-angiogenic molecule (VEGFR tyrosine kinase inhibitor (TKI)). These combinations are now recommended in first line setting for mccRCC, according to the last European recommendations. In the face of these new therapeutic options, the question of selecting the best treatment arises as well as the optimal sequence. Predictive biomarkers are required to guide the therapeutic choice and provide a personalized treatment for each patient. This narrative review will provide an overview of the main predictive biomarkers assessed in mccRCC treatment, with a particular focus on mRNA panel signatures.

[Impact of molecular signatures on the choice of systemic treatment for metastatic kidney cancer]

The standard of care for metastatic clear cell renal cell carcinoma (mccRCC) has changed dramatically over the past decades thanks to the increasing number of treatments: anti-VEGFR tyrosine kinase inhibitors (TKI), mTOR inhibitors and immune checkpoint inhibitors (ICI): anti PD(L)-1 used as monotherapy or in combination with anti CTLA-4 or anti angiogenic therapies. In the face of rising therapeutic options, the question of the therapeutic sequences arises: which treatment for which patient? Actually, there is a lack of predictive biomarkers. A greater understanding of the cancer biology and its interaction with the microenvironment has allowed the development of genomic signatures which could perhaps be used as predictive biomarker. This review will give an insight on some robust genomic signatures assessed in mccRCC and will have a closer look at BIONIKK phase II trial, which is the first trial to adapt treatments according to the molecular characteristics of the tumor in the context of mccRCC.