Menlo Park, California, June 1, 2023 – Summit Therapeutics Inc. (NASDAQ: SMMT) (“Summit,” “we,” or the “Company”) today announced that data for its novel, potential first-in-class investigational bispecific antibody, ivonescimab, will be presented at the 2023 American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago, IL. The poster with updated clinical data from Phase II clinical trials will be displayed on Sunday June 4 from 8:00 to 11:00am Central Time during the Lung Cancer – Non-Small Cell Metastatic Poster Session.
The poster, which is presented by Dr. Li Zhang, Sun Yat-Sen University Cancer Center,1 with data generated and analyzed by our collaboration and licensing partner, Akeso, Inc. (HKEX Code: 9926.HK), provides updated results from the Phase II study (NCT04736823) centered around the cohort of patients in which ivonescimab is combined with chemotherapy (n=135) for first line treatment of advanced or metastatic non-small cell lung cancer (NSCLC) in patients without actionable genomic alterations (i.e., positive for endothelial growth factor receptor (EGFR) mutations or anaplastic lymphoma kinase (ALK)). The poster provides updated data supporting promising anti-tumor activity of ivonescimab in first line advanced or metastatic NSCLC, while displaying that ivonescimab may have an acceptable safety profile in combination with platinum-doublet chemotherapy for patients with squamous or non-squamous advanced or metastatic NSCLC in this clinical study.
Ivonescimab, known as SMT112 in the United States, Canada, Europe, and Japan, and as AK112 in China and Australia, is a novel, potential first-in-class investigational bispecific antibody combining the effects of immunotherapy via a blockade of PD-1 with the anti-angiogenesis effects associated with blocking VEGF into a single molecule. There is higher expression (presence) of both PD-1 and VEGF in tumor tissue and the tumor microenvironment (TME) as compared to normal, healthy tissue in the body. Ivonescimab’s tetravalent structure (four binding sites) enables higher avidity (accumulated strength of multiple binding interactions) with over 10 fold increased binding affinity to PD-1 in the presence of VEGF in vitro in tumor cells.2 This tetravalent structure, the intentional design of the molecule, and bringing these two targets into a single bispecific antibody have the potential to steer ivonescimab to the tumor tissue versus healthy tissue, which are intended to improve side effects and safety concerns associated with these targets and have the potential to focus the antitumor activity of both targets. Over 750 patients have been treated with ivonescimab across multiple clinical studies in different indications in China and Australia.
Summit has begun its clinical development of ivonescimab in two NSCLC indications:
- Ivonescimab combined with chemotherapy in patients with epidermal growth factor receptor (EGFR)- mutated, locally advanced or metastatic non-squamous NSCLC who have progressed after treatment with a third-generation EGFR tyrosine kinase inhibitor (TKI) (HARMONi trial or AK112-301)
- Ivonescimab combined with chemotherapy in first-line metastatic squamous NSCLC patients (HARMONi-3 trial)
In May 2023, the first patient was treated in Summit’s licensed territories in the Phase III HARMONi clinical trial. Summit intends to dose patients in the HARMONi-3 trial during the second half of 2023.
Lung cancer is believed to impact approximately 238,0003 people in the United States each year and approximately 477,0004 in Europe. NSCLC is the most prevalent type of lung cancer and represents approximately 80% to 85% of all incidences.5 Among patients with non-squamous NSCLC, approximately 15% have EGFR-sensitizing mutations in the United States and Europe.6 Patients with squamous histology represent approximately 25% to 30% of NSCLC patients.7
1 Poster Authors: Li Zhang, Wenfeng Fang, Yuanyuan Zhao, Yunpeng Yang, Ningning Zhou, Likun Chen, Yan Huang, Jianhua Chen, Li Zhuang, Yingying Du, Qitao Yu, Wu Zhuang, Yanqiu Zhao, Ming Zhou, Weidong Zhang, Yu Zhang, Yixin Wan, Weifeng Song, Michelle Xia
2 Zhong et al, SITC 2022
3 American Cancer Society: Lung Cancer Statistics | How Common is Lung Cancer?
4 World Health Organization: 908-europe-fact-sheets.pdf (iarc.fr)
5 Schabath MB, Cote ML. Cancer Progress and Priorities: Lung Cancer. Cancer Epidemiology, Biomarkers & Prevention. (2019).
6 About EGFR-Positive Lung Cancer | Navigating EGFR (lungevity.org)
7 Schabath MB, Cote ML. Cancer Progress and Priorities: Lung Cancer. Cancer Epidemiology, Biomarkers & Prevention. (2019).