Behind the Approval of Astellas' Drug: New Gastric Cancer Treatment Vyloy Achieves First Milestone!

After previous rejections, Astellas reached a milestone to celebrate over the weekend when its new stomach cancer treatment, Vyloy (zolbetuximab), received its first approval from the U.S. Food and Drug Administration (FDA).

On Friday, the FDA officially approved Vyloy as a first-line treatment for ClDN18.2-positive adult patients with locally advanced unresectable or metastatic human epidermal growth factor receptor 2 (HER2) negative gastric or gastroesophageal junction adenocarcinoma. This approval marks Vyloy as the first anti-ClDN18.2 (known as Claudin-18.2) drug approved in the United States, a transmembrane protein that has become a high-profile target in oncology. It has attracted the attention of several companies, including AstraZeneca, Leap Therapeutics, Legend and Moderna.

The FDA approval specifically covers Vyloy in combination with fluoropyrimidine and platinum-containing chemotherapy agents. To ensure patient availability, the FDA has approved both Ventana Medical System and Roche's CLDN18.2-positive companion diagnostic test.

In clinical studies, Vyloy has demonstrated significant efficacy. In the SPOTLIGHT study, which included 565 patients, the median progression-free survival (PFS) of patients in the Vyloy combined chemotherapy group was 10.6 months, which was significantly better than 8.7 months in the placebo combined chemotherapy group. At the same time, the median overall survival (OS) of patients in the Vyloy group was 18.2 months, which was also better than 15.5 months in the control group. Another GLOW study of 507 patients showed that Vyloy helped patients achieve a median PFS of 8.2 months, compared to 6.8 months in the placebo/chemotherapy group, and a median OS of 14.4 months and 12.2 months, respectively.

It's worth noting that Vyloy's path to approval was not smooth. Despite being granted a priority review label by the FDA in July 2023, after receiving a full response letter in January, the FDA rejected the application for the drug due to unresolved deficiencies identified during pre-licensing inspections at third-party manufacturing facilities. However, Astellas responded quickly, announcing in late May that the FDA had accepted its resubmitted application.

The approval of Vyloy is significant for Astellas. The company acquired its interest in Vyloy in 2016 when it acquired Ganymed Pharmaceuticals for $1.4 billion. Despite setbacks in the U.S. regulatory process, Vyloy has received several approvals overseas, including a successful listing in Japan. In addition, Vyloy has received regulatory approvals in Europe and the United Kingdom.

While Astellas currently has a leading position in the anti-ClDN18.2 field, several other companies are also actively advancing clinical trials of related drug candidates. For example, Astrazeneca has invested tens of millions of dollars to acquire global rights to an antibody-drug conjugate that targets CLDN18.2. At the same time, while Merck has adjusted its business in this area, other companies such as Kellen are still showing positive research results and potential.