Open-Label, Single-Arm, Phase II Study of Pembrolizumab Monotherapy as First-Line Therapy in Patients With Advanced Non-Clear Cell Renal Cell Carcinoma.

Programmed death 1 (PD-1) pathway inhibitors have not been prospectively evaluated in patients with non-clear cell renal cell carcinoma (nccRCC). The phase II KEYNOTE-427 study (cohort B) was conducted to assess the efficacy and safety of single-agent pembrolizumab, a PD-1 inhibitor, in advanced nccRCC.

Patients with histologically confirmed, measurable (Response Evaluation Criteria in Solid Tumors [RECIST] version 1.1) nccRCC and no prior systemic therapy received pembrolizumab 200 mg intravenously once every 3 weeks for ≤ 24 months. The primary end point was objective response rate (ORR) per RECIST v1.1.

Among enrolled patients (N = 165), 71.5% had confirmed papillary, 12.7% had chromophobe, and 15.8% had unclassified RCC histology. Most patients (67.9%) had intermediate or poor International Metastatic RCC Database Consortium risk status and tumors with programmed death ligand 1 (PD-L1) combined positive score (CPS) ≥ 1 (61.8%). The median time from enrollment to database cutoff was 31.5 months (range, 22.7-38.8). In all patients, the ORR was 26.7%. The median duration of response was 29.0 months; 59.7% of responses lasted ≥ 12 months. The ORR by CPS ≥ 1 and CPS < 1 status was 35.3% and 12.1%, respectively. The ORR by histology was 28.8% for papillary, 9.5% for chromophobe, and 30.8% for unclassified. Overall, the median progression-free survival was 4.2 months (95% CI, 2.9 to 5.6); the 24-month rate was 18.6%. The median overall survival was 28.9 months (95% CI, 24.3 months to not reached); the 24-month rate was 58.4%. Overall, 69.7% of patients reported treatment-related adverse events, most commonly pruritus (20.0%) and hypothyroidism (14.5%). Two deaths were treatment related (pneumonitis and cardiac arrest).

First-line pembrolizumab monotherapy showed promising antitumor activity in nccRCC. The safety profile was similar to that observed in other tumor types.

Journal of clinical oncology : official journal of the American Society of Clinical Oncology. 2021 Feb 02 [Epub ahead of print]

David F McDermott, Jae-Lyun Lee, Marek Ziobro, Cristina Suarez, Przemyslaw Langiewicz, Vsevolod Borisovich Matveev, Pawel Wiechno, Rustem Airatovich Gafanov, Piotr Tomczak, Frederic Pouliot, Frede Donskov, Boris Yakovlevich Alekseev, Sang Joon Shin, Georg A Bjarnason, Daniel Castellano, Rachel Kloss Silverman, Rodolfo F Perini, Charles Schloss, Michael B Atkins

Beth Israel Deaconess Medical Center, Boston, MA., Asan Medical Center and University of Ulsan College of Medicine, Seoul, South Korea., Centrum Onkologii-Instytut im. Marii Sklodowskiej, Cracow, Poland., Medical Oncology, Vall d'Hebron Institute of Oncology (VHIO), Hospital Universitari Vall d'Hebron, Vall d'Hebron Barcelona Hospital Campus, Barcelona, Spain., Wojskowy Instytut Medyczny Centralny Szpital Medyczny MON, Warszawa, Poland., N.N. Blokhin Russian Cancer Research Center, Moscow, Russia., Narodowy Instytut Onkologii-Państwowy Instytut Badawczy im. Marii Skłodowskiej-Curie, Warsaw, Poland., Russian Scientific Center of Roentgenoradiology, Moscow, Russia., Clinical Hospital No. 1 of the Poznan University of Medical Sciences, Poznań, Poland., CHU de Quebec and Laval University, Quebec City, QC, Canada., Aarhus University Hospital, Aarhus, Denmark., P. A. Herzen Moscow Oncology Research Institute, Ministry of Health of the Russian Federation, Moscow, Russia., Yonsei University College of Medicine, Seoul, South Korea., Sunnybrook Odette Cancer Centre, Toronto, ON, Canada., Hospital Universitario 12 de Octubre, I +12 Research Institute, Madrid, Spain., Merck & Co, Inc, Kenilworth, NJ., Georgetown Lombardi Comprehensive Cancer Center, Washington, DC.