Hyrnuo: New Oral Treatment for Advanced HER2-Mutant Lung Cancer

Hyrnuo (sevabertinib) is a new oral medicine for adults with advanced nonsquamous non-small-cell lung cancer (NSCLC) carrying a specific genetic change known as HER2 (ERBB2) TKD activating mutations and whose cancer has either advanced locally or has spread to other parts of the body. It belongs to a group of medicines called kinase inhibitors, which work by blocking signals that help cancer cells grow and spread.

The FDA also approved a special lab test to check if your cancer has the right HER2 mutation for this treatment.

HER2 mutations are found in only a small number of people with NSCLC – about 2%-4% – and treatment options for this group are limited. Unlike broad-spectrum HER2-blocking medicines that produce modest benefits, earlier intervention with HER2-directed treatments can be effective in managing cancer. But they may also carry significant side effects. Newer, more selective HER2-targeted therapies such as zongertinib (approved by the FDA in August 2025) and Hyrnuo have shown encouraging results.

Hyrnuo provides a new option for people whose cancer has gotten worse after they tried other standard therapies. Since it’s taken by mouth, it may be easier to use than some other cancer treatments that require visits to a clinic or a hospital.

Why Was It Approved?

The FDA gave accelerated approval to Hyrnuo based on a clinical study that showed promising results in people having advanced NSCLC with HER2 (ERBB2) TKD activating mutations.

Hyrnuo was tested in people who had previously received standard therapy. Among 70 patients who had never received a HER2-targeted medicine, 71% had tumor shrinkage lasting a median of 9.2 months, with 54% sustaining the benefit for at least six months. Among 52 patients who had previously received HER2-targeted antibody-drug conjugates, 38% showed tumor shrinkage lasting a median of seven months, with 60% having the benefit for at least six months.

The most common side effect reported in the study was diarrhea, which affected most people, although serious cases were less common. Other side effects included skin rashes, nail infections, and mouth sores.

What Do I Need to Know?

Hyrnuo is taken twice daily by mouth with food. You’ll keep taking it as long as it works for you and the side effects are manageable. Before starting Hyrnuo, tell your health care provider if you have any liver or lung problems or any issue with your pancreas. Let them know about all the medicines that you take, including over-the-counter products, herbal remedies, and vitamin supplements.

Diarrhea is the most common side effect. If it becomes hard to manage, your health care provider may reduce your dose. The medicine label warns that Hyrnuo may also cause liver problems, lung inflammation, eye issues, and high pancreatic enzyme levels. Serious side effects are rare, but you should call your health care provider right away if you have trouble breathing or notice changes in your vision or signs of liver problems, such as yellowing of the skin or dark urine.

Let your health care provider know if you are pregnant or planning to get pregnant, as Hyrnuo is not safe to use during pregnancy because it may harm a fetus.