Phase 1b/2 study of penpulimab (AK105), an antiprogrammed cell death-1 immunoglobulin G1 antibody, in advanced or metastatic solid tumors (AK105-204)

BACKGROUND

Penpulimab, a new-generation antiprogrammed cell death-1 immunoglobulin G1 monoclonal antibody, was engineered to optimize receptor occupancy and eliminate fragment crystallizable γ-mediated effector function. In this multicenter, phase 1b/2, multicohort study, the objective was to investigate the efficacy, safety, and immunogenicity of penpulimab in advanced solid tumors.

METHODS

Patients who had unresectable, advanced solid tumors were enrolled from six centers and received 200 mg penpulimab on day 1 every 2 weeks for up to 24 months. The primary end point was the objective response rate (ORR) according to Response Evaluation Criteria in Solid Tumors, version criteria 1.1.

RESULTS

Between September 2, 2019, and January 1, 2020, 65 patients were enrolled and received penpulimab. At the time of data cutoff (May 11, 2022), the median follow-up was 12.6 months (range, 1.1-28.6 months). The ORR was 12.3 (95% confidence interval [CI], 5.5%-22.8%), with three (4.6%) complete responses and five (7.7%) partial responses. Twelve patients (18.5%) achieved stable disease, resulting in a disease control rate of 30.8% (95% CI, 19.9%-43.4%). The median duration of response was not reached (95% CI, 6.70 months to not estimable). In all cohorts, the median progression-free survival was 1.74 months (95% CI, 1.41-2.69 months), and the median overall survival was 16.59 months (95% CI, 7.82-22.18 months). Grade 3 or greater treatment-related adverse events and immune-related adverse events occurred in 9.2% and 27.7% of patients, respectively. Positive antidrug antibody responses to penpulimab were observed in one patient (1.8%).

CONCLUSIONS

Penpulimab showed promising antitumor activity with an acceptable safety profile, offering a potential new treatment approach for solid tumors. These findings supported the evaluation of penpulimab's durable activity and safety, as monotherapy or in combination therapy, in specific malignancies.

Advances and challenges of immunocheckpoint inhibitors in the treatment of primary liver cancer

Primary liver cancer (PLC) is one of the most common malignant tumors, which clinically characterized by occult onset, rapid development, easy recurrence and poor prognosis. With the rapid development of tumor immunotherapy research, tumor immunotherapy has also achieved remarkable clinical efficacy, and jointly promoted the overall improvement of tumor immunology from mechanism research to clinical transformation, from single discipline to multi-disciplinary integration. Immunotherapy has obvious advantages in treatment-related toxicity and efficacy compared with traditional therapy. In hepatocellular carcinoma (HCC), immunotherapy alone or in combination with other therapies may help to control tumor progression, and there are many immune checkpoint inhibitors (ICIs) widely used in clinical or ongoing clinical trials. However, tumor immunology research is still facing many challenges. How to effectively evaluate the efficacy, whether there are related biomarkers, the generation of immune tolerance and the lack of clinical trials to objectively evaluate the efficacy are still urgent problems to be solved, but it also brings new research opportunities for basic and clinical immunology researchers. The study of treatment of ICIs of PLC has become a hot spot in clinical research field. This paper summarizes and prospects the research progress and challenges of ICIs for PLC.

Penpulimab: First Approval

Penpulimab (^®) is a humanised anti-programmed cell death 1 (PD-1) monoclonal antibody developed by Akeso Biopharma, in collaboration with Chia Tai Tianqing (a subsidiary of SinoBiopharm), for the treatment of various cancers, including Hodgkin's lymphoma, nasopharyngeal cancer, non-small cell lung cancer (NSCLC) and solid tumours. Penpulimab is an immunoglobulin G1 monoclonal antibody engineered to completely eliminate Fcγ receptor binding and Fc-mediated effector functions that can compromise anti-tumour activity. In August 2021, penpulimab received its first approval in China for the treatment of adult patients with relapsed or refractory classic Hodgkin's lymphoma who have undergone at least second-line chemotherapy. Penpulimab is under regulatory review for nasopharyngeal cancer and NSCLC in China. Clinical studies of penpulimab are underway for various cancers in China and Australia. This article summarizes the milestones in the development of penpulimab leading to this first approval for relapsed or refractory classic Hodgkin's lymphoma.