86P - Efficacy and safety of HLX07 monotherapy in advanced cutaneous squamous cell carcinoma: An open-label, multicentre phase II study

Background

High EGFR expression has been observed in about 50% of advanced cutaneous squamous cell carcinoma (CSCC). EGFR inhibitor is recommended in NCCN guidelines for some later-line patients. However, no EGFR inhibitor has been approved as a first-line option worldwide. This study aimed to evaluate the efficacy and safety of HLX07 (a novel humanised anti-EGFR antibody) monotherapy in patients with advanced CSCC, including first-line patient.

Methods

This single-arm, open-label, multicentre phase 2 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 were enrolled to receive intravenous HLX07 at 1500 mg (group A) or 1000 mg (group B), Q3W in part 1. The primary endpoint was independent radiological review committee (IRRC)-assessed objective response rate (ORR) per RECIST 1.1. Secondary endpoints included other efficacy measures, safety, pharmacokinetics, immunogenicity, and quality-of-life assessment.

Results

As of 2 July 2023, 31 patients were enrolled and assigned to group A (n=21) and group B (n=10) in part 1. The median age was 60 years; 16 (51.6%) patients were male. Among the 29 efficacy evaluable patients (21 in group A and 8 in group B), the median follow-up duration was 9.6 months and 3.1 months in the respective groups. IRRC-assessed unconfirmed ORR was 23.8% (95% CI 8.2–47.2) in group A and 62.5% (95% CI 24.5–91.5) in group B. IRRC-assessed median PFS was 3.6 months (95% CI 1.4–5.9) in group A and not reached in group B. Median OS was not reached in either group. Among the 31 patients who received study treatment, grade ≥3 treatment-related adverse events (TRAEs) occurred in 8 (38.1%) and 2 (20.0%) patients in group A and B, respectively, most commonly hypomagnesaemia (14.3% vs. 10.0%) and rash (4.8% vs. 10.0%). No TRAE leading to death was reported.

Conclusions

HLX07 monotherapy demonstrated encouraging antitumour efficacy and was well-tolerated in patients with advanced CSCC.

Clinical trial identification

NCT05238363 (released on 14 February 2022).

Editorial acknowledgement

Editorial assistance was provided by Zhi Hao Kwok, Shiqi Zhong, 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, J. Zhu: Financial Interests, Personal, Full or part-time Employment: Shanghai Henlius Biotech, Inc. All other authors have declared no conflicts of interest.