MIAMI — Elderly patients are underrepresented in clinical trials of treatments for metastatic renal cell carcinoma, according to a presenter at International Kidney Cancer Symposium.
Consequently, oncologists lack guidelines or data to help inform treatment decisions for this population, Neeraj Agarwal, MD, director of genitourinary medical oncology at Huntsman Cancer Institute at University of Utah, said during a presentation.
The median age for patients diagnosed with kidney and renal pelvic cancer is 64 years, and median age at death is 71 years. However, less than 30% of patients in clinical trials for these malignancies are aged 65 years or older.
Agarwal attributed this to drug distribution; drug metabolism; mutations in drug-metabolizing enzymes; polypharmacy, which leads to drug-drug interactions; and increasing comorbidities.
“We see an increasing number of targeted therapies and immunotherapies for these elderly patients, but there are no clear guidelines for the treatment of these patients,” Agarwal said. “Most of the decisions we make in the clinic are extrapolated from clinical trial data, which include predominantly younger patients.”
Agarwal and colleagues analyzed data on treatment efficacy and toxicity from clinical trials by age for first-line and salvage treatment of patients with metastatic renal cell carcinoma, as well as data from a meta-analysis.
The researchers compared trials designed to evaluate several first-line treatments: sunitinib (Sutent, Pfizer), pazopanib (Votrient, Novartis), sorafenib (Nexavar, Bayer) and cabozantinib (Cabometyx, Exelixis).
Efficacy among elderly and nonelderly patients treated with these agents in the first-line setting appeared similar; however, toxicity data were not available for all trials. Therefore, these results do not allow for a fair comparison or a decision about the ideal option, Agarwal said.
Among salvage-line therapies, researchers evaluated data on nivolumab (Keytruda, Merck), cabozantinib, axitinib (Inlyta, Pfizer), and the combination of lenvatinib (Lenvima, Eisai) and everolimus (Afinitor, Novartis).
Efficacy appeared similar for elderly and nonelderly patients; however, inconsistent reporting of toxicity data once again failed to allow for a fair comparison.
A Bayesian meta-analysis used network information to construct indirect comparisons of key randomized trials of patients with metastatic renal cell carcinoma.
The meta-analysis revealed a trend toward lower efficacy of first-line treatment options among elderly patients. The analysis did not suggest a difference in efficacy in the salvage setting between elderly and non-elderly patients.
“No specific recommendations may be made for elderly patients favoring a specific agent or regimen based on the efficacy data,” Agarwal said.
He emphasized the key role that toxicity data may play in the investigation of treatment options for elderly patients with metastatic renal cell carcinoma.
“We do not have the toxicity data that have been reported in a consistent fashion,” Agarwal said. “In making any treatment decision, it is very important to have efficacy data and — especially in an elderly population — toxicity data. This should be mandated in all registration trials. When efficacy is similar, toxicities may serve as an invaluable guide for treatment selection.” by Kristie L. Kahl
Agarwal N. How should we treat older adults with RCC? Presented at: International Kidney Cancer Symposium; Nov. 3-4, 2017; Miami.
Disclosure: Agarwal reports consultant roles with Bristol-Myers Squibb, Clovis, Eisai, EMD Serono, Exelixis, Genentech, Merck, Novartis and Pfizer.