• First patient dosed in U.S. phase 1 clinical trial of TJ-CD4B/ABL111 in patients with advanced or metastatic solid tumors
• China sites to join the dose expansion part of the study to accelerate TJ-CD4B/ABL111 development
• Results of TJ-L14B/ABL503 preclinical studies accepted for publication in Journal for ImmunoTherapy of Cancer

TJ-CD4B/ABL111 is the only clinical-stage bispecific antibody that binds to Claudin 18.2 (CLDN18.2)-expressing cancer cells and co-stimulatory molecule 4-1BB on immune cells to elicit a localized and combined immune response against solid tumors. Preclinical studies have demonstrated superior CLDN18.2-dependent immune activation with TJ-CD4B/ABL111 compared to 4-1BB monoclonal antibodies. The anti-tumor activity is achieved locally at the tumor site with no hepatotoxicity or systemic side effects that are commonly seen with 4-1BB monoclonal antibodies when used alone. Studies have also demonstrated a memory response that can resist tumor rechallenge for a long-lasting treatment effect.

A U.S. phase 1 clinical trial of TJ-CD4B/ABL111 in advanced or metastatic solid tumors (NCT04900818) has been initiated with the first patient being dosed on June 29, 2021. The phase 1 clinical study is a multi-center dose escalation and dose expansion study. To accelerate TJ-CD4B/ABL111 development, China sites will join the dose expansion part of the study. Patients with gastric cancer, esophageal adenocarcinoma and pancreatic cancer in China will be enrolled later this year.

TJ-L14B/ABL503 is another novel bispecific antibody uniquely designed to activate 4-1BB signalling in the presence of PD-L1, while simultaneously blocking PD-1/PD-L1 signalling. Preclinical studies have demonstrated superior anti-tumor activity for TJ-L14B/ABL503 compared to equimolar doses of 4-1BB and PD-L1 monoclonal antibodies single agents alone or in combination. The data suggest that TJ-L14B/ABL503 induced anti-tumor response was protective against tumor rechallenge in animal studies. These results have now been accepted for publication by the Journal for ImmunoTherapy of Cancer (JITC), titled "Novel anti-4-1BB X PD-L1 bispecific antibody augments anti-tumor immunity through tumor-directed T-cell activation and checkpoint blockade." A phase 1 clinical trial for TJ-L14B/ABL503 was initiated in the U.S. earlier in April 2021 in patients with locally advanced or metastatic solid tumors (NCT04762641).

"As the next-wave of innovation in immuno-oncology, bispecific antibodies could be a promising solution to cancers that are resistant to the existing standard of care," said Dr. Joan Shen, CEO of I-Mab. "With the rapid development of our bispecific antibody portfolio, we are excited to progress one of the world's first echelon of 4-1BB bispecific antibodies in the clinic."