Pembrolizumab, Axitinib Combo Extends Survival in Advanced Renal Cancer Study

First-line therapy with a combination of pembrolizumab (Keytruda, Merck) and axitinib (Inlyta, Pfizer) extended both overall survival (OS) and progression-free survival in patients with clear-cell metastatic renal cell carcinoma (mRCC), according to new data from a phase 3 study.

Prognosis for advanced RCC remains poor, with a 5-year survival rate for patients with metastatic RCC of approximately 12%. Ninety-five percent of deaths from kidney cancer in the United States in 2019 will result from renal cell cancers, according to the American Society of Clinical Oncology.

The KEYNOTE-426 clinical trial evaluated the combination therapy compared with the current standard of care, sunitinib (Sutent), in 861 patients with untreated clear-cell mRCC. Patients were randomly assigned to oral sunitinib once daily or to combination therapy with pembrolizumab given intravenously every 3 weeks along with oral axitinib twice daily.

Key findings from a comparison at median follow-up of 12.8 months showed that:

• Combination therapy was associated with a 47% reduction in risk of death compared with sunitinib. The 12-month OS was 89.9% in the combination group versus 78.3% in the sunitinib group.
• Patients treated with the combination therapy lived a median of 15.1 months without disease progression versus 11.1 months when treated with sunitinib.
• An OS of 59.3% in the combination therapy arm versus 35.7% in the sunitinib arm.
• The duration of response was longer in patients treated with the combination, with a median not yet reached versus 15.2 months in sunitinib.
• Fifty-nine percent of patients who received the combination continue to be treated versus 43.1% of patients who received sunitinib.

“These results are exciting,” co-lead study author Thomas Powles, MD, professor of urology oncology at Barts Cancer Institute, said in a statement. “By adding pembrolizumab to a VEGF-targeted therapy, we are seeing powerful anticancer responses, including improved survival — and importantly, the results are seen across broad subgroups of patients.”

The findings build on data from an earlier phase 1b trial that showed pembrolizumab plus axitinib had a manageable safety profile and a 73% response rate among this patient population. The study authors noted that the results showed that axitinib was easier to combine with pembrolizumab than some other antiangiogenic drugs in the same class as sunitinib.

Additionally, the study showed serious treatment-related adverse effects in 62.9% of patients on the combination therapy compared with 58.1% in those who received sunitinib.

Although the findings are promising for the advancement of care in renal cancer, Dr Powles noted that other questions remain, particularly concerning PD-L1 levels as a biomarker in the disease.

“It is possible that by combining pembrolizumab with axitinib, the predictive value of PD-L1 is being masked,” Dr Powles said. “Overall, we have not previously seen a renal cancer study which has improved response, progression-free survival, and overall survival. This is therefore a major step forward in renal cancer.”

Reference

Pembrolizumab Plus Axitinib Extended Overall Survival and Progression-Free Survival Versus Current Standard Treatment for Advanced Kidney Cancer [news release]. American Society of Clinical Oncology. https://www.asco.org/about-asco/press-center/news-releases/pembrolizumab-plus-axitinib-extended-overall-survival-and. Accessed February 12, 2019.