Tevimbra Is Now Approved for Four Uses in Esophageal and Stomach Cancers. In Its Main Stomach Cancer Trial, Adding It to Chemotherapy Helped Patients Live About 2 Months Longer Overall and About 4.6 Months Longer When Their Tumors Had Higher Levels of PD-L1.

A reader asked me to look into Tevimbra, and the request made sense. It had one US approval in 2024 and has four now. This week's paper is the main trial behind its stomach cancer approval, published in the BMJ.

Your immune system has built-in brakes that keep it from attacking healthy tissue. One of those brakes is a protein on immune cells called PD-1. Some tumors cover themselves in a protein called PD-L1, which presses that brake and tells immune cells to stand down. Tevimbra blocks PD-1, so the brake cannot be pressed and the immune system can go after the cancer. This type of drug is called immunotherapy, and Tevimbra belongs to a group called checkpoint inhibitors.

Doctors measure PD-L1 in the tumor because it can help predict who will benefit. In this trial, PD-L1 was measured with a lab test on a sample of each tumor and reported as a percentage called the TAP score. This review calls a score of 5% or higher "high PD-L1."

• —Biomarker: something measured in a tumor that helps predict which treatment will work. PD-L1 and HER2 are both biomarkers.
• —HER2: a protein on the surface of some cancer cells that helps them grow. A tumor is HER2-positive if it has a lot of it and HER2-negative if it does not. Some drugs, including trastuzumab and zanidatamab, target HER2.
• —First treatment (first-line): the first treatment given once cancer is advanced.
• —Unresectable: cannot be removed by surgery.
• —Metastatic: has spread to other parts of the body.
• —Gastroesophageal junction: the place where the esophagus meets the stomach.
• —Squamous cell cancer and adenocarcinoma: two types of cancer named for the cells they start in. Squamous cell cancer of the esophagus starts in the flat cells lining it, and adenocarcinoma starts in gland-type cells.
• —Placebo: a treatment with no active drug, used for comparison.
• —Double-blind: neither patients nor doctors know who received the real drug.
• —Median survival: the point at which half of the patients are still alive.

All four uses are for adults whose cancer cannot be removed by surgery or has spread.

• —March 2024: esophageal squamous cell cancer after earlier chemotherapy.
• —December 2024: first treatment for HER2-negative stomach and gastroesophageal junction cancer, given with chemotherapy, for tumors with PD-L1.
• —March 2025: first treatment for esophageal squamous cell cancer, given with chemotherapy, for tumors with PD-L1.
• —August 2026: first treatment for HER2-positive stomach, junction, or esophageal adenocarcinoma, given with chemotherapy and a second drug called zanidatamab.

The trial enrolled 997 adults with advanced stomach or gastroesophageal junction cancer that had not been treated before. All of the tumors were HER2-negative. Half of the patients received chemotherapy plus Tevimbra, and half received chemotherapy plus a placebo. The trial was double-blind. The researchers also measured PD-L1 in each tumor, because they expected it to affect how well the drug worked.

About 55% of patients had high PD-L1. In that group, half of the patients on Tevimbra lived at least 17.2 months, compared with 12.6 months on chemotherapy alone. Across all patients, the figures were 15.0 months and 12.9 months.

Severe side effects related to treatment happened in 54% of patients on Tevimbra and 50% of patients on chemotherapy alone.

The August 2026 approval is for patients whose tumors are HER2-positive. In that trial, 914 patients received either the new three-drug combination or the older standard, which was trastuzumab with chemotherapy. The median time before the cancer grew was 12.4 months with the new combination and 8.1 months with the older treatment. Half of the patients on the new combination lived at least 26.4 months. This approval means HER2 testing at diagnosis now decides which first treatments are options.

• —The BMJ results come from an early planned analysis. Later results with longer follow-up have been published separately.
• —This trial included only HER2-negative patients, so it does not apply to the HER2-positive approval.
• —Drug trials like this one are usually run by the drug's manufacturer, so readers should check the funding statement in the paper.
• —The HER2-positive numbers here come from news reports of the approval, not the full trial paper, which requires a subscription.

Tevimbra is a new first-treatment option for several esophageal and stomach cancers, and how much it helps depends on the tumor. Patients with higher PD-L1 levels gained the most in the main stomach cancer trial, and the newest approval depends on HER2 status instead. Treatment choices belong to patients and their oncology teams.

HERIZON-GEA-01 phase 3 trial, published in the New England Journal of Medicine. Full text requires a subscription.

FDA approval reports:

• —OncLive: https://www.onclive.com/view/fda-approves-tislelizumab-for-advanced-or-metastatic-escc-after-chemotherapy
• —Cancer Network: https://www.cancernetwork.com/view/fda-approves-tislelizumab-chemo-in-gastric-gej-adenocarcinoma
• —Pharmacy Times: https://www.pharmacytimes.com/view/tislelizumab-jsgr-plus-chemotherapy-receives-fda-approval-for-advanced-esophageal-squamous-cell-carcinoma
• —The ASCO Post: https://ascopost.com/news/august-2026/fda-approves-zanidatamab-combination-regimens-for-her2-gastric-gej-or-esophageal-cancer/
• —Medscape: https://www.medscape.com/viewarticle/fda-approves-zanidatamab-regimen-her2-positive-gea-2026a1000tsr