The treatment of kidney cancer is evolving with first-line combination therapies, including nivolumab plus ipilimumab and axitinib plus pembrolizumab, and first-line drug options that depend on risk of disease, such as cabozantinib and pazopanib.
Biomarkers can be categorised as follows:
- Diagnostic – identifies the presence of cancer (malignancy)
- Prognostic – baseline patient or disease characteristics that give an indication of risk for disease recurrence/progression
- Predictive – baseline characteristics that give an indication of response to a particular treatment
- Pharmacodynamic – dynamic assessment showing a biological response has occurred after treatment with a particular drug
- Discovery – biomarker that gives an indication of genetic changes that cause tumour growth, metastases and resistance to drug treatment
- Surrogate – biomarker intended to substitute for a clinical efficacy endpoint.
Biomarkers will help doctors determine who will respond to drug treatment, why patients develop resistance to drug treatment, what the next/best treatment is, determine how to combine treatments, assess when resistance should be targeted, and help identify the next generation of drugs. In summary:
- There is an urgent need for predictive biomarkers
- Single tumour biopsies may not represent the heterogeneity of RCC
- Liquid biopsies may capture the heterogeneity, but it remains to be determined how a single cell protein analysis correlates with primary or metastatic tumours
- Single-cell phenotypic analysis shows early clinical correlations for immune checkpoint inhibitor and TKI therapies
- But ultimately, can we do better than CT scans to identify emerging signs of resistance?