Authors: Eva Muñoz Couselo, Brett Gordon Maxwell Hughes, Laurent Mortier, Jean-Jacques Grob, Ralf Gutzmer, Osama Roshdy, Rene Lazaro Gonzalez Mendoza, Jacob Schachter, Ana Maria Arance, Florent Grange, Nicolas Meyer, Abhishek Jagdish Joshi, Salem Billan, Sven Erik Ojavee, Jianda Yuan, Burak Gumuscu, Åse Bratland
Published: 2024-07-03
DOI: 10.1200/jco.2024.42.16_suppl.9554
Source: Full article
9554 Background: Pembro monotherapy is approved in certain countries, including the US, for treatment of LA or R/M cSCC based on results from the open-label phase 2 KEYNOTE-629 trial (NCT03284424). Promising antitumor activity was demonstrated with pembro in both the LA and R/M cohorts. ORR (95% CI) was 50.0% (36.1-63.9; 16.7% CRs) in the LA cohort and 35.2% (26.2-45.2; 10.5% CRs) in the R/M cohort. We present data from KEYNOTE-629 with an additional follow-up of 38 mo for LA and R/M cohorts. Methods: Adults with histologically confirmed LA or R/M cSCC, measurable disease per RECIST v1.1 by blinded independent central review (BICR), and ECOG PS 0 or 1 received pembro 200 mg IV every 3 weeks for up to 35 cycles (~2 years). The primary end point was ORR per RECIST v1.1 by BICR. Secondary end points were DOR, DCR (CR + PR + SD ≥12 wks), and PFS per RECIST v1.1 by BICR; OS; and safety. End points were analyzed in pts who received ≥1 dose of pembro. Results: A total of 159 pts were treated with pembro (LA, n = 54; R/M, n = 105). As of September 13, 2023, 33 pts (20.8%) completed treatment and 126 pts (79.2%) discontinued treatment. Median (range) follow-up was 52.4 mo (47.6-56.9) for the LA cohort, 64.7 mo (62.1-69.5) for the R/M cohort, and 63.1 mo (47.6-69.5) in the total population. ORR and DCR are shown in the table. Median DOR (range) was 47.2 mo (1.0+ to 49.9+) in the LA cohort, not reached (NR; 2.7 to 64.2+ mo) in the R/M cohort, and 52.5 mo (1.0+ to 64.2+) in the total population; the proportion of responders with responses ≥12 mo by Kaplan-Meier estimate were 84.8%, 77.8%, and 80.7%, respectively. Median (95% CI) PFS was 14.4 mo (5.5-43.6) in the LA cohort, 5.7 mo (3.1-8.5) in the R/M cohort, and 8.0 mo (5.3-14.4) in the total population; 12-mo rates were 56.7%, 37.3%, and 43.7%, respectively. Median (95% CI) OS was NR (33.3-NR) in the LA cohort, 23.8 mo (13.4-30.9) in the R/M cohort, and 29.8 mo (20.0-42.8) in the total population; 36-mo rates were 62.0%, 39.5%, and 47.0%, respectively. Grade 3-5 treatment-related AEs occurred in 11.3% of pts, and grade 3-5 immune-mediated AEs and infusion reactions occurred in 8.8% of pts. Two pts (1.3%) died due to a treatment-related AE (colitis, cranial nerve disorder). Conclusions: With a median follow-up of more than 5 years, pembro continued to show durable responses in pts with LA or R/M cSCC. No new safety signals were observed. Results from this study continue to support the use of pembro in this pt population. Clinical trial information: NCT03284424 . [Table: see text]