Abstract 759P
Background
High epidermal growth factor receptor (EGFR) expression was observed in about 50% of advanced cutaneous squamous cell carcinoma (CSCC), suggesting that targeting the EGFR pathway may be a promising treatment strategy. This is a single-arm, open-label, multicentre phase II study evaluating the efficacy and safety of HLX07 (a novel humanised anti-EGFR antibody) as a first- or late-line option in advanced CSCC patients. Previous results were presented at the 2023 ESMO Asia Congress. Here we present the updated results with an extended follow-up of 17.9 months.
Methods
This study consisted of 2 parts. Part 1 explored the preliminary efficacy and was presented below; part 2 evaluated the efficacy and safety of HLX07 (at a fixed dose based on part 1) in a larger cohort. Patients with advanced CSCC harbouring lymph node or distant metastasis, or locally advanced CSCC that was not amenable to surgery/radical radiation therapy received intravenous HLX07 at 1500 mg (group A) or 1000 mg (group B) once every 3 weeks in part 1. The primary endpoint was independent radiological review committee (IRRC)-assessed ORR per RECIST 1.1. Secondary endpoints included other efficacy measures, safety, pharmacokinetics, immunogenicity, and quality-of-life assessments.
Results
By the data cutoff date of April 30, 2024, the median follow-up duration was 19.1 months and 12.7 months in group A (n=21), and B (n=10), respectively. IRRC-assessed confirmed ORR was 19.0% (95% CI 5.5–41.9) in group A and 60.0% (95% CI 26.2–87.8) in group B. IRRC-assessed median progression-free survival was 4.9 months (95% CI 1.4–6.5) in group A and 7.9 months (95% CI 2.2–11.1) in group B. Median OS was 11.8 months (95% CI 5.9–NE) in group A and not reached in group B, with a 12-month OS rate of 45.7% and 56.0% for the respective groups. Grade ≥3 treatment-related adverse events (TRAEs) occurred in 8 (38.1%), and 3 (30.0%) patients in group A, and B, respectively. No TRAE leading to treatment discontinuation or death was reported.
Conclusions
With an additional 8.9 months of follow-up, HLX07 monotherapy at 1000 mg continued to demonstrate encouraging antitumour efficacy along with manageable safety in Chinese patients with advanced CSCC.
Clinical trial identification
NCT05238363: (released on 14 February 2022).
Editorial acknowledgement
Abstract writing support was provided by Zhi Hao Kwok, and Chen Hu of Shanghai Henlius Biotech, Inc.
Legal entity responsible for the study
Shanghai Henlius Biotech, Inc.
Funding
Shanghai Henlius Biotech, Inc.
Disclosure
X. Hu, L. Wang, Q. Wang: Financial Interests, Institutional, Full or part-time Employment: Shanghai Henlius Biotech, Inc. All other authors have declared no conflicts of interest.