On September 11, 2023, ImmuneOnco Biopharmaceuticals (Shanghai) Co., Ltd. (referred to as "ImmuneOnco", Hong Kong Stock Exchange stock code: 01541.HK) announced that IMM27M， an independently developed ADCC-enhanced CTLA-4 antibody, completed the phase I dose escalation patient enrollment and determined the recommended phase II dose. This is another milestone event in the company's rapid development.

The first patient was dosed in June 2022. The Phase I dose escalation trial of the IMM27M for solid tumors is progressing smoothly. Overall data showed that IMM27M was well tolerated, without dose-limiting toxicities (DLTs) occurring in all subjects across the seven dose groups of 0.1 mg/kg to 7.5 mg/kg. Among them, initial objective response (both obtained PR) was observed in 2 breast cancer patients after multiple lines of treatment at dose of 3 mg/kg and 5 mg/kg respectively; in addition, another subject with advanced melanoma achieved SD with 20% tumor size shrinkage at 2 mg/kg dose level. After reviewed clinical data, the Safety Review Committee (SRC) unanimously agreed that 5mg/kg Q3W should be RP2D used as monotherapy.

On August 17, the Phase II clinical research application for IMM27M combined with IMM2510 was accepted by the National Medical Products Administration (NMPA). Preclinical studies have shown that IMM2510 produces stronger synergistic anti-tumor activity than that of anti-VEGF combined with PD-L1 antibody. Repeated in vivo studies have demonstrated that IMM27M has strong anti-tumor activity and can be used in clinical studies in combination with a variety of drugs in the company's pipeline. Dual immune therapy of CTLA4 combined with PD1/PD-L1 has been well established to have clear cut synergy. In addition, in March this year, the Phase II IND application for IMM27M combined with PD1 to treat different advanced solid tumors has been approved by CDE.

Dr. Tian, Wenzhi, founder and chairman of ImmuneOnco, said:

"I am very pleased to see that our IMM27M completed the enrollment of patients in phase I dose escalation and determined the recommended phase II dose. IMM27M is an IgG1 antibody against CTLA-4. It has been genetically engineered to significantly enhance ADCC activity. Compared with similar molecule lpilimumab, the efficacy in animal models of IMM27M was much better at the same dose levels, and tumors can be eliminated at a lower dose (0.3 mg/kg). Repeatable in vivo studies showed that IMM27M had powerful anti-tumor activity. It can be also used in combination with a variety of drugs in the company's pipeline. We believe that IMM27M have great value for clinical development. We will work closely with clinical experts and subjects to accelerate the clinical research of IMM27M and benefit cancer patients as soon as possible.”

Dr. Lu， Qiying, chief medical officer/senior vice president of ImmuneOnco, said:

"Today is a special day for our company that IMM27M completed the phase I dose escalation and determined the recommended phase II dose. IMM27M is a second-generation antibody against CTLA-4 with good safety and tolerability. No DLT was observed in any dose level of phase I study. 2 patients with hormone receptor-positive breast cancer who relapsed after multiple lines achieved PR. We will further evaluate the efficacy by combining antibodies with different targets, such as combination with PD-1, and IMM2510 (vEGF/PD-L1), are being actively explored in different solid tumors, and we look forward to bringing good news to the cancer patients."