Promising Intracranial Anti-Tumor Activity and Safety Data for Ivonescimab in NSCLC Patients with Brain Metastases Featured at ELCC 2024

Summit Therapeutics Inc. (NASDAQ: SMMT) (“Summit,” “we,” or the “Company”) today announced promising data for its novel, potential first-in-class investigational bispecific antibody, ivonescimab, that is being presented today at the 2024 European Lung Cancer Congress (ELCC 2024) in Prague, Czech Republic. Two posters featuring updated ivonescimab data will be displayed from 12:00 to 12:45pm Central European Time. The posters will also be made available on our website after the presentation period.

The first poster, “Intracranial Activity of Ivonescimab Alone or in Combination with Platinum Doublet Chemotherapy in Patients with Advanced Non-Small Cell Lung Cancer (NSCLC) and Brain Metastases” includes data from patients with asymptomatic brain metastases at baseline. These patients were enrolled in either AK112-202 (NCT04900363), in which ivonescimab is delivered as monotherapy, or AK112-201 (NCT04736823), in which ivonescimab is delivered in combination with platinum doublet chemotherapy, both of which are Phase II clinical trials for patients with advanced or metastatic NSCLC. This analysis consisted of the 35 patients with advanced or metastatic NSCLC who had asymptomatic brain metastases at baseline; 28 patients were treated with ivonescimab plus chemotherapy in AK112-201, and seven patients were treated with monotherapy ivonescimab in AK112-202.

Notably, median intracranial progression-free survival was 19.3 months across all patients analyzed. Patients across both cohorts experienced an intracranial response rate of 34%, and eight patients (23%) experienced a complete response by RANO criteria. All patients who did not achieve a response demonstrated stable disease or non-progression; no patients experienced intracranial disease progression at the time of the initial follow-up scan. No cases of intracranial bleeding complications were observed in these patients.

“We are pleased to see ivonescimab’s favorable intracranial response rates and median intracranial progression-free survival as well as promising anti-tumor activity and safety profile in the subgroup of patients with brain metastases from NSCLC,” said Dr. H. Jack West, Vice President of Clinical Development at Summit. “We are grateful for the patients and clinical investigators supporting these trials, and our ongoing collaboration with our partners at Akeso.”