Zolbetuximab: A New Hope for Stomach Cancer Treatment
Stomach cancer (also called gastric cancer) is one of the leading causes of cancer deaths in the world. Even with today’s treatments like chemotherapy, many patients don’t get the results they need. But there's exciting news: a new medicine called zolbetuximab is showing real promise in helping certain people with this kind of cancer.
In this blog, we’ll walk you through what zolbetuximab is, how it works, why testing for certain markers in your cancer is important, and how Navexio is helping patients get access to new options like this.
What Is Zolbetuximab?
Zolbetuximab (pronounced zole-beh-TOO-ksi-mab) is a special kind of medicine called a monoclonal antibody. That’s a fancy way of saying it’s designed to find and attack a specific target on cancer cells. In this case, that target is something called CLDN18.2—a protein that shows up on the surface of certain stomach cancer cells but not on most healthy cells [1].
Think of CLDN18.2 as a flag waving on the cancer cell. Zolbetuximab sees that flag, locks onto it, and helps the immune system destroy the cancer.
Does Zolbetuximab Work?
Yes—and the results from large clinical trials have been impressive.
In the GLOW study, researchers gave one group of patients zolbetuximab with chemotherapy and gave another group just chemotherapy. The group that got zolbetuximab lived longer and stayed cancer-free for more time [1].
People taking zolbetuximab lived for about 14.4 months, compared to 12.2 months without it.
Their cancer didn’t get worse for about 8.2 months, compared to 6.8 months without it.
Another trial called SPOTLIGHT showed similar benefits when zolbetuximab was combined with a different type of chemo. Patients lived longer, and their cancer was kept under control for more time [2].
These are meaningful improvements for people with advanced stomach or gastroesophageal cancers who often face limited options.
What About Side Effects?
Like many cancer treatments, zolbetuximab does come with side effects. The most common are nausea and vomiting, especially in the first few weeks [1]. Doctors now know to give medicines ahead of time to help manage these symptoms. While some people had more serious side effects, they were mostly similar to those seen with chemo alone.
So while it’s not without risks, zolbetuximab’s benefits can outweigh the downsides for the right patients.
Why Biomarker Testing Matters
Here’s the catch—zolbetuximab only works if your cancer has the CLDN18.2 flag. This means testing your tumor is a must.
Doctors use a lab test called immunohistochemistry (or IHC) to see if CLDN18.2 is present in your cancer. If it is, you could be a good fit for this treatment.
That’s why biomarker testing is becoming such a big deal in cancer care. It helps doctors choose the best treatment based on the unique biology of your tumor—not just where it started in the body [3].
What’s Next for Zolbetuximab?
Zolbetuximab, sold under the brand name VYLOY®, has now been approved in the U.S., Europe, and Japan for certain stomach cancers [4]. It’s also recommended in top cancer guidelines like those from the National Comprehensive Cancer Network (NCCN) [3].
Researchers are now testing zolbetuximab in other combinations, including with immunotherapy—another exciting kind of cancer treatment that helps your immune system fight back harder [5].
Where Navexio Comes In
At Navexio, we believe every cancer patient deserves access to the best information, the right tests, and all available treatment options—wherever they live.
New drugs like zolbetuximab show why that matters. If you don’t know to test for CLDN18.2, you might miss the chance to benefit from this breakthrough. That’s why our expert cancer navigators work directly with patients and families to guide them through diagnostic testing, explain results, and explore global treatment options that may not yet be available in local hospitals.
We help you understand the science in plain language, ask the right questions, and make sure no stone is left unturned in your care.
If you or someone you love is facing cancer, especially stomach or gastroesophageal cancer, reach out to learn how Navexio can support you on your journey.
References
Shitara K, et al. Zolbetuximab plus CAPOX in CLDN18.2-positive gastric or gastroesophageal junction adenocarcinoma: GLOW trial. Nature Medicine. 2023. https://www.nature.com/articles/s41591-023-02465-7
Shitara K, et al. Zolbetuximab plus mFOLFOX6 in CLDN18.2-positive gastric/GEJ adenocarcinoma: SPOTLIGHT trial. Lancet. 2023;401(10380):1655-1668.
NCCN Guidelines® for Gastric Cancer V.1.2025. National Comprehensive Cancer Network. https://www.nccn.org
Zolbetuximab. Wikipedia. Accessed May 3, 2025. https://en.wikipedia.org/wiki/Zolbetuximab
ClinicalTrials.gov. ILUSTRO Study: NCT03505320. https://clinicaltrials.gov/ct2/show/NCT03505320