Novel Antibody-Drug Conjugate Shows Promise for Patients With Certain Gastric Cancer

For immediate release
November 6, 2023


Rachel Cagan Facci

ASCO Expert Perspective
“The recent phase III SPOTLIGHT and GLOW studies put CLDN18.2 on the map as a viable target for gastroesophageal cancer. It is one of the most exciting new targets for patients with advanced gastroesophageal cancer and CMG901 represents a new way to interrogate this target. What’s exciting for patients is the potential for an entirely new class of therapies for advanced gastroesophageal cancer—we will all eagerly await future studies.”
Pamela Kunz, MD, ASCO Expert in Gastrointestinal Cancers

A first-in-class antibody-drug conjugate called CMG901 targeting claudin 18.2 (also referred to as CLDN18.2) may be a potential new treatment option for patients with claudin 18.2-positive gastric or gastroesophageal junction cancer. These results will be presented during the November 2023 session of the American Society of Clinical Oncology (ASCO) Plenary Series.

While there has been recent progress in the management of gastric and gastroesophageal junction cancer, there has been limited gains in the area of targeted therapy according to the authors. CLDN18.2 is a protein that is commonly found on cancer cells in the stomach gastroesophageal junction. This is the first trial to assess the efficacy and safety of CMG901, a potential first-in-class CLDN18.2-specific antibody-drug conjugate – or an antibody covalently attached to cytotoxic drugs via a chemical linker – for patients with advanced gastric or gastroesophageal junction cancer.

This study in China consisted of a dose escalation phase (part A; dose range 0.3-3.4 mg/kg) and a dose-expansion phase (part B; doses of 2.2, 2.6, and 3.0 mg/kg) to evaluate the safety, tolerability, and anti-tumor activity of CMG901 in patients with advanced gastric or gastroesophageal junction cancers and other solid tumors. Primary endpoints were safety and tolerability as well as maximum tolerated dose for part A, and objective response rate – or a reduction in tumor size – and recommended phase 2 dose in part B.

Maximum tolerated dose was not reached during dose escalation. A total of 113 patients (6 patients from part A and 107 patients from part B) received CMG901 at doses of 2.2-3.0 mg/kg. Of 89 CLDN18.2-positive patients with at least 1 post-treatment scan, confirmed objective response rate was 32.6%. For all 93 CLDN18.2-positive patients, the median progression-free survival was 4.76 months after a median follow-up of 5.98 months.

“Based on the results in this study, it was found that CMG901 was active in this heavily pretreated population with a manageable safety profile. CMG901 appears to be a promising therapeutic agent for CLDN 18.2-expressing gastric and gastroesophageal junction cancers—an area of high unmet medical need,” said lead study author Rui-hua Xu, MD, PhD from Sun Yat-sen University Cancer Center in Guangzhou, China. 

Presentation will be available here on November 7, 2023 at 3:00 pm ET. View the abstract here.

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