On May 15, 2025, ImmuneOnco Biopharmaceuticals (Shanghai) Inc. (referred to as “ImmuneOnco,” Hong Kong Stock Exchange stock code: 01541.HK) announced that the Phase Ib/II clinical trial application for tazlestobart (IMM27M) combined with osimertinib for the treatment of EGFR-mutated locally advanced or metastatic NsqNSCLC, has been officially approved by NMPA. This milestone marks another critical step in ImmuneOnco’s rapid development of tazlestobart (IMM27M) in clinical research.

EGFR-mutated locally advanced or metastatic NsqNSCLC is a common subtype of lung cancer, particularly in Asian populations where EGFR mutations are highly prevalent. While epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) (e.g., osimertinib) serves as the first-line standard treatment, drug resistance remains a significant challenge.

Studies have demonstrated that EGFR-TKI (e.g., osimertinib) induces upregulation of the immune checkpoint cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), thereby promoting immunosuppression in the tumor microenvironment. Combining CTLA-4 inhibitors with EGFR-TKI can restore T-cell effector function, reverse CTLA-4-mediated suppression, and enhance efficacy against TKI-resistant tumors.^【1】

In mouse models, the combination of osimertinib with a CTLA-4 inhibitor significantly prolonged overall survival, demonstrating clear superiority over osimertinib monotherapy and osimertinib combined with a PD-1 antibody.

Tazlestobart (IMM27M), an Immunoglobulin G1 (IgG1) antibody targeting CTLA-4, has been genetically engineered to significantly enhance antibody-dependent cell-mediated cytotoxicity (ADCC) activity. It effectively depletes regulatory T cells in the tumor microenvironment, amplifying anti-tumor immune responses. This mechanism, when combined with EGFR-TKIs, may improve outcomes in drug-resistant patients.

Additionally, repeated in vivo studies have confirmed tazlestobart (IMM27M)’s robust anti-tumor activity and its potential for combination with a variety of other pipeline drugs. A clinical study of palverafusp alfa (IMM2510) combined with tazlestobart (IMM27M) in advanced solid tumors is currently enrolling patients.

Dr. Tian, Wenzhi, Founder, Chairman, CEO, and CSO of ImmuneOnco, said:
“The approval of this clinical trial for tazlestobart (IMM27M) combined with osimertinib represents another important advancement for ImmuneOnco in tumor immunotherapy. This approved clinical trial focuses on EGFR-mutated locally advanced or metastatic NsqNSCLC patients, whose unmet medical needs remain significant. If the combination demonstrates favorable safety and efficacy in clinical trials, it may offer a novel therapeutic option for this patient population. This achievement not only underscores ImmuneOnco’s innovation in drug development but also brings new hope and a brighter future to patients. We will go all out to advance the clinical trial process to ensure this innovative therapy benefits patients as soon as possible.”

Reference：【1】Minjie Fu, Jiaxu Zhao, Licheng Zhang, et al. Cancer Cell. 2024 Nov 11;42(11):1882-1897.e7.