‘Reimb targeted therapies for Stage IV gastric cancer'

‘Reimbursing targeted therapies may be key to solving Stage 4 gastric cancer in Korea'

Claudin18.2 targeted therapy Vyloy shows benfits in Asian patients as well

First targeted therapy introduced in 14 years…need to expand access to the treatment

A targeted therapy option for gastric cancer that demonstrated exceptional survival extension benefits in Asian patients is on the verge of being listed for insurance reimbursement in Korea.

 

If reimbursed, the medical community expects the improved access to the new drug will contribute to improving the persistently low survival rates among metastatic gastric cancer patients.

 

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According to industry sources on the 24th, the Health Insurance Review and Assessment Service (HIRA) plans to convene its 8th Cancer Disease Deliberation Committee meeting later this month.

 

Among the treatments likely to be reviewed, Astellas' gastric cancer drug ‘Vyloy (zolbetuximab)’ is a prominent candidate.

 

Vyloy is the first new drug introduced in the gastric cancer field in 14 years since HER2-targeted therapies, and it was the world's first drug approved for patients with Claudin 18.2-positive metastatic gastric cancer.

 

It was approved in Korea last September.

 

The treatment is an IgG1 monoclonal antibody that binds selectively to Claudin 18.2, a protein expressed in the stomach.

 

It works by binding to the Claudin-18.2 protein expressed on gastric epithelial tumor cells.

 

Claudins are a type of protein that regulates the exchange of cellular molecules and maintains cell junctions.

 

They are expressed at limited levels in healthy tissues but are overexpressed in certain solid tumors.

 

Among these, Claudin-18.2 is known to be expressed in gastrointestinal cancers such as gastric and pancreatic cancer.

 

This protein is expressed in approximately 38% of all gastric cancer patients, which far exceeds the HER2-positive population (10-15%).

 

Unlike lung or breast cancer, where various targeted and immunotherapy drugs have emerged to improve survival rates, gastric cancer has long been a barren field for targeted therapy.

 

This is because biomarkers capable of targeting metastatic gastric cancer cells were limited.

 

This stands in stark contrast to lung cancer, where the relative survival rate at the metastatic stage more than doubled from 4.9% in 2011 to 12.9% in 2022.

 

Until now, approximately 90% of metastatic gastric cancer patients diagnosed as HER2-negative have had virtually no available targeted therapy options.

 

The introduction of Vyloy has provided new treatment opportunities for about 40% of patients, leading the clinical field to regard it as a paradigm shift in gastric cancer treatment.

 

Vyloy showed exceptional survival benefit in Asian patient populations, including Koreans.

 

According to the SPOTLIGHT clinical, which was conducted in Claudin18.2-positive, HER2-negative metastatic gastric cancer patients, the median progression-free survival (PFS) in the Vyloy group was 12.55 months for Asian patients, longer than the 9.69 months for non-Asian patients.

 

Overall survival (OS) also exceeded that of non-Asian patients at 21.49 months versus 16.99 months.

 

Dae-young Zang, president of the Korean Gastric Cancer Association (Department of Hemato-Oncology, Hallym University Sacred Heart Hospital), emphasized, “The Korean subgroup analysis of the pivotal study showed that median overall survival was 30 months — nearly double that of the placebo group.

 

Vyloy represents a significant therapeutic advancement that can substantially improve survival outcomes for Korean patients with metastatic gastric cancer.” KGCA recommends Vyloy at the ‘strongest level’...reimbursement needed Reflecting this data, the Korean Gastric Cancer Association issued a ‘strong recommendation’ in January this year via its official journal JGC (Journal of Gastric Cancer) for Vyloy as a first-line therapy for HER2-negative, Claudin18.2-positive metastatic gastric cancer patients.

 

However, Vyloy's clinical value is not being fully realized on site.

 

This is because it is not yet reimbursed by national health insurance, leaving many patients unable to afford the high treatment costs.

 

Metastatic gastric cancer is a disease with a pronounced survival gap based on income level.

 

According to Statistics Korea data, the mortality risk for the lowest income group among gastric cancer patients in Korea is 1.72 times higher than that of the highest income group.

 

This structure effectively means that the burden of treatment costs determines survival.

 

In contrast, Japan approved the drug and granted its reimbursement simultaneously last March, with over 3,000 patients already receiving Vyloy treatment.

 

Considering that Japan's gastric cancer incidence rate per 100,000 people is similar to Korea's (Japan: 27.6, Korea: 27), Korea's delayed coverage is leading to a clear gap in treatment accessibility.

 

South Korea is a globally recognized leader in gastric cancer treatment.

 

The 5-year relative survival rate for all gastric cancer patients reaches 77.5%, and for localized gastric cancer confined to the stomach, it is 97.4%, approaching a cure.

 

As of 2022, approximately 62% of gastric cancer patients in South Korea are diagnosed at an early, localized stage, supporting this achievement.

 

However, even within this early-diagnosis-focused structure, blind spots persist.

 

The medical community is increasingly focusing on the low survival rates of metastatic (stage IV) gastric cancer patients.

 

Accounting for about 10% of all gastric cancer patients, these individuals face difficulty in receiving treatment because the cancer has already spread at the time of diagnosis.

 

The actual 5-year relative survival rate for metastatic gastric cancer patients in Korea is 7.5%, meaning only 7 out of 100 patients survive beyond 5 years.

 

This is the lowest among the five major cancers, showing a significant gap compared to lung cancer (12.9%), colorectal cancer (20.6%), breast cancer (49%), and thyroid cancer (63.7%).

 

The average survival period is also only about one and a half years.

 

Zang said, “As a global leader in gastric cancer care, Korea should act swiftly to provide reimbursement for Vyloy to offer an opportunity for survival to patients and drive innovation in gastric cancer treatment worldwide.”