KEYNOTE-427 cohort B: First-line pembrolizumab (pembro) monotherapy for advanced non‒clear cell renal cell carcinoma (NCC-RCC)

• Published in: Journal of clinical oncology Vol. 37; no. 15_suppl; p. 4569
• Main Authors: Lee, Jae-Lyun, Ziobro, Marek, Gafanov, Rustem, Matveev, Vsevolod Borisovich, Suarez, Cristina, Donskov, Frede, Pouliot, Frederic, Alekseev, Boris Yakovlevich, Wiechno, Pawel J., Tomczak, Piotr, Climent, Miguel Ángel, Shin, Sang Joon, Silverman, Rachel Kloss, Perini, Rodolfo F., Schloss, Charles, McDermott, David F., Atkins, Michael B.
• Format: Journal Article
• Language: English
• Published: 20-05-2019
• ISSN: 0732-183X; 1527-7755
• DOI: 10.1200/JCO.2019.37.15_suppl.4569

Abstract only 4569 Background: Efficacy of PD-1 inhibitors (or any therapy) in NCC-RCC has not been established. KEYNOTE-427 (NCT02853344) is a single-arm, open-label, phase 2 study of pembro monotherapy in patients (pts) with advanced clear cell RCC (cohort A) and NCC-RCC (cohort B). Cohort B results are presented. Methods: 165 pts with histologically confirmed NCC-RCC, no prior systemic therapy, measurable disease (RECIST v1.1), and KPS ≥70% enrolled. Pts received pembro 200 mg IV Q3W for 35 cycles (~2 y) or until progressive disease (PD), unacceptable toxicity, or withdrawal. Primary end point: objective response rate (ORR) per RECIST v1.1 by blinded independent central review. Additional end points: duration of response (DOR), population description by sarcomatoid differentiation, histology and PD-L1 expression (combined positive score [CPS] ≥1 for PD-L1+). Results: Histology was confirmed by a central pathologist: papillary 72% (n = 118), chromophobe 13% (n = 21), unclassified 16% (n = 26); 62% were PD-L1+. At analysis, 49 pts had died and 3 had withdrawn. At median follow-up of 11.1 mo (range, 0.9-21.3), 56% of pts discontinued pembro due to PD or clinical progression. Overall ORR was 24.8% (95% CI, 18.5-32.2; 8 [4.8%] CR, 33 [20.0%] PR). Median DOR was not reached. For responding pts, 81.5% had a response ≥6 mo. 12-mo PFS and OS rates were 22.8% and 72.0%, respectively. ORR (95% CI) was 25.4% (17.9-34.3) with papillary, 9.5% (1.2-30.4) with chromophobe, and 34.6% (17.2-55.7) with unclassified NCC-RCC; for responding pts, 82.1%, 50.0%, and 87.5% had a response ≥6 mo, respectively. Median DOR was not reached in any group. ORR (95% CI) was 44.7% (28.6-61.7) for pts with sarcomatoid differentiation (n = 38). ORR (95% CI) was 33.3% (24.3-43.4) and 10.3% (3.9-21.2) with CPS≥1 and CPS < 1, respectively. Grade 3-5 treatment-related adverse events (TRAEs) occurred in 11% of pts. 6 pts died of AEs, 2 of TRAEs (pneumonia and cardiac arrest). Conclusions: Single-agent pembro showed encouraging antitumor activity in NCC-RCC, especially with papillary or unclassified histology. Safety profile of pembro was as expected. Updated data with additional follow-up will be presented. Clinical trial information: NCT02853344.