I-Mab Receives FDA Orphan Drug Designation for its Novel Claudin 18.2 x 4-1BB Bispecific Antibody TJ-CD4B for the Treatment of Gastric Cancer
I-Mab (the “Company”) (Nasdaq: IMAB), a clinical-stage biopharmaceutical company committed to the discovery, development, and commercialization of novel biologics, today announced that the U.S. Food and Drug Administration (FDA) has granted Orphan Drug Designation for TJ-CD4B, a novel Claudin 18.2 x 4-1BB bispecific antibody, for the treatment of gastric cancer including cancer of gastroesophageal junction.
“The Orphan Drug Designation underscores the FDA’s recognition of TJ-CD4B’s potential promise as a novel therapy for gastric cancer and other related cancers,” said Dr. Andrew Zhu, President of I-Mab. “TJ-CD4B is designed to work through a novel mechanism of action and is being tested in cancer patients. With the Orphan Drug Designation, we expect to expedite its global clinical development and potentially offer a novel treatment option for such an aggressive group of cancers that have very poor prognosis.”
TJ-CD4B is the first clinical-stage bispecific antibody that binds to Claudin 18.2 (CLDN18.2)-expressing cancer cells and co-stimulatory molecule 4-1BB on T cells to exert a tumor-killing effect. Unlike other therapies involving CLDN18.2, TJ-CD4B has a broader anti-tumor effect covering cancers expressing low levels of CLDN18.2. Preclinical studies have suggested that TJ-CD4B is superior to current CLDN18.2 antibodies and 4-1BB agonistic antibodies due to its stronger anti-tumor activity and a minimal 4-1BB related systemic toxicity.
TJ-CD4B is part of I-Mab’s highly innovative bispecific antibody pipeline. It is currently undergoing phase 1 clinical trials (NCT04900818) both in the U.S. and China in patients with advanced solid tumors, including gastric cancer, gastroesophageal junction carcinoma, esophageal adenocarcinoma, and pancreatic ductal carcinoma. I-Mab has made significant progress in the global clinical development of TJ-CD4B. In the ongoing dose-escalation study, TJ-CD4B was safe and well-tolerated at dose up to 3 mg/kg weekly. The Company plans to advance the study in biomarker-selected population subsequently.
Gastric cancer is the fifth most common cancer and third most common cause of death due to cancers globally. As the condition is asymptomatic in the early stages, it is generally diagnosed in advanced stages and carries a poor prognosis. Existing therapies for advanced refractory gastric cancer offer only modest clinical outcomes. In the U.S., gastric cancer is found in about 26,000 persons every year and accounts for about 1.5% of all new cancers diagnosed. In China, gastric cancer is the second most frequently diagnosed cancer and the second leading cause of cancer–related deaths.
The FDA grants Orphan Drug Designation to investigational drugs and biologics that are intended for the treatment of rare diseases that affect fewer than 200,000 people in the U.S. Orphan Drug Designation provides drug developers with various benefits designed to support the development of novel drugs and biologics, including market exclusivity for seven years upon FDA approval, tax credits for qualified clinical trials, and exemption from FDA application fees.
 American Cancer Society. Key Statistics about stomach cancer. Available at: https://www.cancer.org/cancer/stomach-cancer/about/key-statistics.html#:~:text=How%20common%20is%20stomach%20cancer,6%2C740%20men%20and%204%2C440%20women)
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