Ivonescimab Shows Promise in CRC, TNBC, and HNSCC at ESMO 2024

Summit Therapeutics Inc. has revealed new data on ivonescimab, a potential first-in-class investigational bispecific antibody, during the 2024 European Society for Medical Oncology Annual Meeting (ESMO 2024) in Barcelona, Spain. The data, derived from Phase II trials in China and sponsored by Akeso Inc., were showcased through two presentations and one poster. The trials focused on advanced triple-negative breast cancer (TNBC), recurrent/metastatic head and neck squamous cell carcinoma (HNSCC), and metastatic microsatellite-stable (MSS) colorectal cancer (CRC).

The first oral presentation, delivered by Dr. Yanhong Deng from Sun Yat-Sen University, centered on the efficacy and safety of ivonescimab with or without ligufalimab alongside FOLFOXIRI chemotherapy as a first-line treatment for metastatic MSS CRC. In this single-region, multicenter, open-label, Phase II randomized study, 22 patients received ivonescimab plus FOLFOXIRI (Group A), while 18 patients were administered ivonescimab plus ligufalimab and FOLFOXIRI (Group B). Findings showed an overall response rate of 81.8% for Group A and 88.2% for Group B, with a 100% disease control rate in both groups. The safety profile was manageable, with common treatment-related adverse events (TRAEs) including anemia and decreased white blood cell counts.

The second presentation by Dr. Xiaojia Wang from Zhejiang Cancer Hospital addressed the safety and efficacy of ivonescimab combined with chemotherapy as a first-line treatment for TNBC. This Phase II study assessed 30 patients who received ivonescimab plus chemotherapy, with data showing a 72.4% overall response rate and a 100% disease control rate. The most frequent TRAEs were reductions in white blood cell counts, ALT and AST increases, alopecia, and neutrophil count decreases.

The poster, presented by Dr. Xiaozhong Chen, evaluated the combination of ivonescimab and ligufalimab as a first-line treatment for PD-L1 positive recurrent/metastatic HNSCC. The study included 10 patients receiving ivonescimab and 20 receiving ivonescimab plus ligufalimab, revealing overall response rates of 30% and 60%, respectively. The safety profile was again acceptable, with proteinuria and dermatitis acneiform being the most common TRAEs.

Ivonescimab, also known as SMT112 in various regions and AK112 in China and Australia, is a novel bispecific antibody that combines PD-1 blockade with VEGF inhibition. This unique structure aims to direct the antibody to tumor tissues, enhancing its binding affinity in the tumor microenvironment. Ivonescimab is currently being investigated in multiple Phase III clinical trials, including those for non-small cell lung cancer (NSCLC).

Summit Therapeutics, established in 2003, is a biopharmaceutical company focused on developing therapies to enhance the quality of life and address unmet medical needs. The company's stock is listed on the Nasdaq Global Market under the symbol "SMMT."