Zolbetuximab plus chemotherapy for locally advanced unresectable or metastatic stomach or gastroesophageal junction cancers: a plain language summary

What is this summary about?: This is a summary of two articles. The first article is about a clinical trial called SPOTLIGHT and it was published in the medical journal The Lancet in in April of 2023. The second article is about a clinical trial called GLOW and it was published in the medical journal Nature Medicine in July of 2023.

What are the key takeaways?: Until recently, chemotherapy was the first treatment given to people with stomach cancer or gastroesophageal junction (or GEJ) cancer that is locally advanced unresectable or metastatic. When cancer cells have high amounts of the protein CLDN18.2 but do not have high amounts of the protein HER2, the cancer is known as CLDN18.2-positive (or CLDN18.2+) and HER2-negative (or HER2-). New medicines to treat cancer are being developed. These medicines attach to proteins on cancer cells to help the body recognize and kill cancer cells.The clinical trials SPOTLIGHT and GLOW included participants with CLDN18.2+ and HER2- stomach or GEJ cancer that was locally advanced unresectable or metastatic. These trials looked at whether adding a medicine called zolbetuximab to chemotherapy as the first treatment for cancer helped people live longer before their tumors grew bigger or new tumors grew, after starting the trial. These studies also looked at whether adding zolbetuximab to chemotherapy helped people live longer after starting the trial.

What were the main conclusions reported by the researchers?: In SPOTLIGHT and GLOW, on average, participants assigned to zolbetuximab plus chemotherapy lived 1.4 to 1.9 months longer before their tumors grew bigger or new tumors grew, after starting the trial, than participants assigned to a placebo plus chemotherapy. On average, participants assigned to zolbetuximab plus chemotherapy also lived 2.2 to 2.7 months longer, after starting the trial, than participants assigned to a placebo plus chemotherapy. These results suggest that zolbetuximab plus chemotherapy could be a new first treatment for people with CLDN18.2+ and HER2- stomach or GEJ cancer that is locally advanced unresectable or metastatic.Clinical Trial Registration: NCT03504397 (SPOTLIGHT); NCT03653507 (GLOW).