Background: Current LA-HNSCC treatment involves surgery and chemoradiation (CRT); however, <50% of patients (pts) are disease-free at 2 years, necessitating new treatments. Anti–PD-1 therapies are standard for pts with HNSCC, yet recent ph3 studies (KEYNOTE-412; IMvoke010) showed no improved outcomes when administered with CRT. In KEYNOTE-412, patients with high PD-L1 expression had numerically improved outcomes than those with low/no expression. JADE will assess the efficacy and safety of sequential dostarlimab vs PBO following CRT for PD-L1+ LA-HNSCC patients.Trial design: JADE is a global, randomised, double-blind, PBO-controlled phase 3 study, currently enrolling patients in 21 countries. Key eligibility includes: ≥18 years of age; newly diagnosed, unresected LA-HNSCC of the oral cavity, oropharynx, hypopharynx, or larynx; completed concurrent CRT with curative intent; no distant metastases and PD-L1+ (combined positive score [CPS] ≥1). 864 pts will be enrolled. Pts will be stratified by tumour site/p16 status (larynx/hypopharynx/oral cavity, and p16 negative/positive oropharynx), cisplatin schedule (high dose, every 3 weeks [Q3W] or low dose, Q1W), and PD-L1 status (CPS 1–19 or ≥20). Following CRT, pts will be randomised 1:1 to receive 500 mg intravenous (IV) dostarlimab or PBO Q3W (4 cycles), followed by 1000 mg IV dostarlimab or PBO Q6W (7 cycles). The primary endpoint is event-free survival (EFS); events are defined as locoregional progression/recurrence/metastasis per blinded independent central review assessment, salvage surgery, neck dissection/surgery >20 weeks after CRT completion, or death. Secondary endpoints include overall survival, EFS per investigator assessment, safety, tolerability, pharmacokinetics, and anti-drug antibodies incidence. Funding: GSK

Conflicts of interest: JD declares advisory board member roles with honoraria for MSD, Merck, Zeiss; JPM declares advisory board member or speaker roles with honoraria for Pfizer, Roche, Bayer, Merck Serono, Boehringer, Bristol Myers Squibb, Novartis, Incyte, Cue Biopharma, ALX Oncology, iTEOS, eTheRNA, NEKTAR, F-Star, Seagen, Genmab, Astellas, CureVac, MSD, GSK, Merus; travel expenses for Amgen, Bristol Myers Squibb, Pfizer, MSD, Gilead, Sanofi; data safety monitoring board role with honoraria for Psioxus; investigator and study coordinator role for the EORTC; and research funding to the institute for Pfizer, Roche, Bayer, Merck Serono, Boehringer-Ingelheim, Bristol Myers Squibb, Novartis, Incyte, Cue Biopharma, ALX Oncology, iTEOS, eTheRNA, NEKTAR, F-Star, Seagen, Genmab, Astellas, CureVac, MSD, GSK, Merus, EORTC, Amgen, MSD, Gilead, Sanofi, Psioxus. BB declares advisory board member role, coordination principal investigator role, and research funding for GSK. KH declares advisory board roles for AstraZeneca, MSD, Merck-Serono; invited speaker roles for MSD, Merck-Serono; local principal investigator roles for AstraZeneca, MSD; research funding for Merck-Serono; speaker, consult or advisor roles for Merck-Serono; and steering committee member role for AstraZeneca, GSK, MSD, Merck-Serono. NS reports advisory board and advisory roles for AstraZeneca, Eisai Medical, Merck EMD Serono, Pfizer, Kura, Vaccinex, CUE, BionTech, GSK, TOSK, Seagen, Flamingo, Infinity, Inovio, Aveo, Medscape, Onclive, Uptodate, Bristol Myers Squibb, Cornerstone, Celldex, Surface Oncology Astex, Imugene, Faron Pharmaceutical, Coherus, Adagene, Fulgent, Springer, Nanobiotix, Taiho, Exelixis, Vaccinex; and funding from Exelixis, Vaccinex. MT declares advisory board member roles for AstraZeneca, Bayer, Boehringer Ingelheim, Lilly, Merck Biopharma, MSD, Ono pharma, Pfizer, Rakuten Medical; invited speaker roles for Bristol- Myers Squibb, Eisai, Novartis; local principal investigator roles for AstraZeneca, Bayer, Bristol-Myers Squibb, GSK, Lilly, Loxo, Merck Biophama, MSD, Novartis, Ono Pharma, Pfizer, Rakuten Medical; and research grants funding to the institute for Bayer. TC, LH, AP, and EZ are employees of and hold financial equities in GSK. DT is an employee of GSK and hold financial equities in GSK and Pfizer. LLS declares advisory board roles for Merck, Pfizer, AstraZeneca, Roche, GSK, Voronoi, Arvinas, Navire, Relay, Marengo, Daiichi Sankyo, Amgen, Medicenna, LTZ Therapeutics, Tubulis, Marengo, Nerviano, Pangea, Incyte, Gilead; research funding to the institute for Merck, Novartis, Bristol Myers Squibb, Pfizer/SeaGen, Boehringer-Ingelheim, GSK, Roche/Genentech, AstraZeneca/Medimmune, Bayer, Abbvie, Amgen, Symphogen, EMD Serono, 23Me, Daiichi Sankyo, Gilead, Marengo, Incyte, LegoChem, Loxo/Eli Lilly, Medicenna, Takara; stocks/ownership in Agios; and a leadership roles in Treadwell Therapeutics.

Disclosure: Previously presented at the European Society for Medical Oncology | 13–17 September 2024 | Barcelona, Spain: 945TiP, J-P. Machiels et al. - Reused with permission.