959P - Combination therapy of envafolimab and suvemcitug in patients with hepatocellular carcinoma (HCC): Results from a phase II clinical trial

Background

The efficacy of immune checkpoint inhibitors combined with antivascular agents has been demonstrated in a variety of solid tumors including HCC. Suvemcitug, selectively binds to and blocks VEGFA from binding to VEGFR1 and 2, thereby inhibiting its activities and preventing tumour angiogenesis and ultimately suppressing tumour growth and metastasis. Envafolimab is a humanized single-domain anti- PD-L1 antibody which is administered subcutaneously (SC). This study aims to assess the efficacy and safety of the combination of suvemcitug and envafolimab as second-line or later therapy in patients (pts) with advanced HCC.

Methods

This was an open-label, multi-cohort, multicenter, phase II trial conducted in China. In Cohort B, eligible pts had received at least one prior line of treatment for HCC and were treated with suvemcitug (2 mg/kg IV Q3W) plus envafolimab (300 mg SC Q3W) until disease progression or unacceptable toxicity was observed. The primary endpoint was objective response rate (ORR) assessed by investigator review using RECIST v1.1. Secondary endpoints included disease control rate (DCR), duration of overall response (DoR), progression-free survival (PFS) and safety.

Results

As of March 31,2023, a total of 20 patients were treated with envafolimab and suvemcitug. 80.0% pts (16/20) received one prior therapy and 40.0% pts (8/20) were prior treated with immunotherapy. After a median follow up of 7.4 (5.0, 9.3) months, in 18 efficacy-evaluable patients, the confirmed ORR was 11.1% (2/18), and the DCR was 72.2% (13/18). The median PFS was 4.3 (95% CI 1.4-8.1) months. The most common grade 3 or greater treatment-related adverse events were proteinuria (20.0%,4/20), hypertension (5%,1/20), platelet count decreased (5%, 1/20), blood bilirubin increased (5%, 1/20), γ-glutamyl transferase increased, oesophagitis (5%, 1/20)，and oral ulcer (5%, 1/20). No treatment-related death was reported.

Conclusions

The use of envafolimab and suvemcitug did not result in increased safety concerns. Suvemcitug and envafolimab demonstrated antitumor activity and manageable safety profile in pts with prior treated HCC. Research Sponsor: Shanghai Xianxiang Medical Technology Co., Ltd. and 3D Medicines Inc.

Clinical trial identification

NCT05148195.

Editorial acknowledgement

Legal entity responsible for the study

Shanghai Xianxiang Medical Technology Co., Ltd. and 3D Medicines Inc.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.