PEMDA-HN, an open-label, phase II, randomized controlled study of danvatirsen plus pembrolizumab compared to pembrolizumab alone in first-line recurrent and/or metastatic head and neck squamous cell carcinoma (RM HNSCC).

Abstract

TPS6113 Background: Signal transducer and activator of transcription 3 (STAT3) plays critical roles in promotion of an immune-suppressive tumor microenvironment and survival of tumor cells. Danvatirsen (DANVA) is a 16-nucleotide, generation 2.5 antisense oligonucleotide designed to down-regulate the expression of human STAT3 mRNA. Over 500 patients with hematologic malignancies or solid tumors have been exposed to DANVA monotherapy or in combination. A tolerable safety profile has been demonstrated for DANVA and toxicities are manageable. The SCORES study in recurrent and/or metastatic (RM) HNSCC patients, naïve to programmed cell death (ligand)1 (PD-(L)1) therapy, demonstrated that DANVA in combination with the PD-L1 inhibitory antibody durvalumab administered in the second line setting appeared to result in a higher objective response rate (ORR) (22.6% [12.3-36.2]) compared with the ORRs seen with durvalumab alone in prior studies (Cohen E. et al. Ann. Oncol., 2018). Several patients had complete responses (CR, 9.4%). The ORR was higher in patients with a PD-L1 tumor proportion score (TPS) ≥1 and ≥20, with increasing benefit noted with higher PD-L1 expression compared with historic anti-PD-(L)1 monotherapy data. The current study aims at evaluating the first-line combination of DANVA with pembrolizumab, an anti-PD-1 agent approved as first-line monotherapy for RM HNSCC in patients with PD-L1 positive disease. Methods: PEMDA-HN is a multicenter, open-label, randomized phase 2 study utilizing a Bayesian Optimal design (BOP2). Approximatively 81 RM HNSCC patients with a PD-L1 combined positive score (CPS) score ≥1 will be randomized in a 2:1 ratio stratified based on CPS<20 and CPS≥20 to receive either DANVA (3 mg/kg IV Days 1, 3, and 5 and then weekly starting on Day 8) and pembrolizumab (200 mg IV every 3 weeks) or pembrolizumab alone as a first line therapy for recurrent or metastatic disease. Eligible patients will receive study treatment until disease progression or discontinuation. The primary endpoint of the study is ORR by response evaluation criteria in solid tumors version 1.1 (RECIST 1.1) as assessed by the investigator. Key secondary objectives are safety, additional antitumor activity evaluation (CR rate, duration of response, disease control rate, progression-free and overall survival) and pharmacokinetics. Efficacy (e.g. ORR, CR rate) will be evaluated in all patients and in subsets of patients with CPS<20, CPS≥20 and CPS≥50. Exploratory endpoints include but are not limited to target engagement and biomarker evaluation. The study is being, or will be, conducted at US, South Korea and United-Kingdom study centers. Clinical trial information: NCT05814666 .