East Montgomery Times

A study from Fox Chase Cancer Center suggests that certain patients with metastatic kidney cancer might safely discontinue combination therapy after two years if they respond well to treatment. This finding could lessen the burden of side effects and complications for some patients. It marks the first clinical trial where stopping treatment was part of the design.

Associate Professor Zibelman, who led the study, remarked, “My main takeaway from this is that there are subsets of patients that can have durable disease control with these drugs, and they may not need to stay on both therapies.” He presented his research at the 2025 American Society of Clinical Oncology (ASCO) Genitourinary Cancers Symposium.

The phase 1/2 trial examined a combination of nivolumab, an immune checkpoint inhibitor, and axitinib, an oral tyrosine kinase inhibitor (TKI), in patients with relapsed metastatic renal cell carcinoma. While newer drugs have outperformed this combination since the trial began seven years ago, Zibelman highlighted the significance of being able to stop treatment.

Out of 26 participants, six opted to cease one or both drugs after two years. Five remained progression-free without additional therapy two years later. Prior studies did not consider stopping therapy as an option.

Zibelman explained that these medications can cause side effects such as diarrhea, fatigue, and skin changes. Oral TKIs in particular may lead to cumulative toxicities due to daily intake. These side effects typically subside when medication is halted.

“Being able to take periods of time off treatment without fear that your cancer is going to immediately progress can be meaningful for patients,” said Zibelman. Halting or pausing therapy also reduces clinic visits and healthcare costs.

The findings might apply broadly to similar drug combinations beyond just nivolumab and axitinib. “For patients who are using an oral therapy and an immunotherapy...they may be able to stop one or both therapies,” Zibelman noted.

Researchers aim to publish results later this year concerning first-line therapy outcomes in kidney cancer patients and explore biomarkers for response or resistance in different drug combinations.

The study titled “Results From the Prior Treatment Cohort of a Phase I/II Study of Nivolumab and Axitinib in Patients With Advanced Renal Cell Carcinoma” was presented at the ASCO Genitourinary Cancers Symposium held in San Francisco from February 13-15.