Is Vyloy (zolbetuximab-clzb) on the market?

Zolbetuximab, branded asVyloy, is a monoclonal antibody used to treat gastric cancer. It is a directed cytolytic antibody directed against claudin-18 isoform 2 Claudin 18.2 (CLDN18.2), developed by Astellas Pharma Inc.

In July 2024, the European Medicines Agency (EMA) adopted a positive opinion recommending the approval of marketing authorization for medicinal products for the treatment of adenocarcinoma of the stomach or gastroesophageal junctionVyloy will obtain medical use authorization in the EU in September 2024. Vyloy was approved for medical use in the United States in October 2024 for the treatment of adenocarcinoma of the stomach or gastroesophageal junction, along with an immunohistochemistry (IHC) companion diagnostic (CDx) test to identify patients who may meet Vyloy criteria.

As a first-in-class monoclonal antibody (mAb), Vyloy targets and binds CLDN18.2, a transmembrane protein. Vyloy depletes CLDN18.2-positive cells via antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC). Vyloy, along with standard chemotherapy, has been shown to slow disease progression and extend survival in patients with advanced gastric or gastroesophageal junction adenocarcinoma. The side effects of adding Vyloy to standard chemotherapy are considered acceptable; they are mainly gastrointestinal symptoms (such as nausea and vomiting), mostly occurring at the beginning of treatment.

The most common adverse reactions to Vyloy include nausea, vomiting, decreased appetite, neutropenia (low levels of neutrophils, a type of infection-fighting white blood cell), low neutrophil count, weight loss, fever, hypoalbuminemia (low levels of albumin, a blood protein), and peripheral edema (swelling, especially in the ankles and feet).