Dr Haas on 5-Year Outcomes With Adjuvant Pembrolizumab in ccRCC

"The study has now reached a median landmark analysis of 6 years. These are the longest data out there that have been presented for adjuvant immune checkpoint inhibitor therapy [for patients with ccRCC]."

Naomi B. Haas, MD, director of the Prostate and Kidney Cancer Program at the Abramson Cancer Center; as well as a professor of medicine (Hematology-Oncology) at the Hospital of the University of Pennsylvania, discussed long-term follow-up data from the phase 3 KEYNOTE-564 study (NCT03142334), which evaluated adjuvant pembrolizumab (Keytruda) in patients with clear cell renal cell carcinoma (ccRCC).

Results from the fourth prespecified interim analysis of KEYNOTE-564 trial, presented at the 2025 ASCO Annual Meeting, further support the benefit of pembrolizumab monotherapy as an adjuvant regimen in patients with ccRCC at increased risk of recurrence following surgery, Haas stated. KEYNOTE-564 established pembrolizumab as the first adjuvant therapy to demonstrate significant improvements in both disease-free survival (DFS) and overall survival (OS) compared with placebo in patients with ccRCC, Haas reported. These latest data from the 6-year landmark analysis, represent the longest follow-up currently available for adjuvant immune checkpoint inhibitor therapy in this setting, she said.

The DFS benefit with pembrolizumab continued to translate to a robust separation of curves that emerged early in the trial and remained consistent over time compared with placebo, reinforcing the durability of benefit, Haas detailed. Importantly, the OS benefit with pembrolizumab also maintained a separation of the curves between the arms, an observation that underscores the potential long-term effect of adjuvant pembrolizumab on survival outcomes, she noted. Notably, the trial did not show the attritional effect that sometimes occurs in long-term studies, where patient drop-out may attenuate survival differences over time, she added.

Safety results were consistent with those seen in prior analyses, with no new serious treatment-related adverse effects identified for the past 3 years, Haas continued, stating that this finding further supports the long-term tolerability of pembrolizumab in the adjuvant setting. The benefit of adjuvant pembrolizumab was also observed consistently across all key subgroups evaluated for both DFS and OS. Taken together, these data reinforce pembrolizumab’s role as a standard-of-care option for patients with ccRCC at increased risk of recurrence following surgery, cementing its place in the evolving adjuvant treatment paradigm, Haas concluded.