Patient group urges faster access to Vyloy by reforming diagnostic rules

A patient organization has called for improving regulations on new technology-assessing procedures to prevent late-stage cancer patients from suffering.

Astellas Pharma’s late-stage gastric cancer drug Vyloy (zolbetuximab) has won approval from the Ministry of Food and Drug Safety (MFDS). However, the companion diagnosis for prescribing this drug could not be used due to regulations on new medical technology evaluation, postponing the drug’s use for nearly a year and threatening the lives of end-stage patients.

“Patients with terminal gastric cancer who need Vyloy treatment should not be put in a precarious situation like a lamp exposed to wind,” the Korea Alliance of Patients Organization said in a news release Wednesday. “Fix the problem that the companion diagnostic device approved simultaneously with Vyloy by the MFDS cannot be used due to the new medical technology evaluation procedure.”

On Sept. 20, 2024, the MFDS approved Vyloy as the first-line treatment of unresectable locally advanced or metastatic gastric adenocarcinoma and gastric-esophageal junction adenocarcinoma in combination with fluoropyrimidine- and platinum-based chemotherapy for patients with Claudin 18.2 (CLDN18.2) positivity and HER2 negativity.

On the same day, the ministry also approved Roche Diagnostics Korea’s VENTANA CLDN18 (43-14A) RxDx Assay, noting that the Claudin 18.2 positivity should be assessed using a companion diagnostic device it approved.

However, the government's evaluation of the Claudin 18.2 companion diagnostic for Vyloy has raised a problem.

Last November, the Health Insurance Review and Assessment Service (HIRA) held the first meeting of its expert evaluation committee and requested evidence, including the listing of major clinical guidelines, for the immunohistochemistry (IHC) test for companion diagnosis of Vyloy. This delayed a decision on whether to recognize it as an existing technology or classify it as a new medical technology. IHC is an experimental method that uses specific antibodies to measure specific antigens in tissue samples.

Each time a new cancer type or biomarker is added in Korea, it must pass a new medical technology evaluation by the National Evidence-based Healthcare Collaborating Agency (NECA) before it can be used. Currently, the IHC test method for Claudin 18.2 is widely used for the diagnosis of HER2 (breast cancer, stomach cancer), ALK (lung cancer), and PD-L1 (lung cancer, stomach cancer), so if it is recognized as an existing technology, it can be used for companion diagnosis of Vyloy.

On Dec. 20 last year, Vyloy was listed as a preferred therapy in the revised version of the U.S. National Comprehensive Cancer Network's (NCCN) gastric cancer guidelines. On Jan. 6, it was also listed as the highest level of recommendation in the online version of the Korean gastric cancer guidelines published by the official journal of the Korean Gastric Cancer Society.

The patient organization expressed concern that if the Claudin 18.2 companion diagnostic is classified as a new medical technology and goes through the evaluation process, it could take a long time before it is available to patients.

“If recognized as an existing technology by the review panel, patients with end-stage gastric cancer would be able to be treated with Vyloy immediately,” the alliance said. “However, if it is subject to a new medical technology evaluation, it could take 80 days for medical device clearance, 140 days for diagnostic test new medical technology evaluation, and 100 days for medical practice coverage, for a total of 320 days before it is available for use.”

During this time, the diagnosis of Claudin 18.2 will be unavailable, and patients with advanced gastric cancer will lose access to treatment, the alliance said.

“This is like driving patients with advanced gastric cancer who are in urgent need of treatment to a situation like a lamp before the wind,” it said.

The patient group asked the government to make a decision after considering the patients’ situations at the second expert evaluation committee next Monday. It also called for improving the companion diagnostic system.

“Please make a careful decision so that the Claudin 18.2 diagnostic gap does not harm terminal gastric cancer patients,” the alliance said. “This case is a symbolic example of the problems with the companion diagnosis system in Korea.”

“With the rapid development of new drugs and advanced medical technologies, patients' access to treatment will be limited unless systemic improvements are made,” it said. “For patients whose lives depend on the timing of treatment, such delays are more than just an inconvenience. It can have life-threatening consequences. We urge the government to improve the system for companion diagnostics immediately.”