What Is Ziihera and How Does It Work?
The FDA has approved Ziihera (zanidatamab-hrii) to treat adults with advanced or spreading gastroesophageal adenocarcinoma (GEA).
GEA includes cancers of the stomach, the esophagus, and the area where the stomach and esophagus meet.
This drug is for patients whose tumors test positive for a specific protein called HER2. It is used as a first-line treatment in combination with standard chemotherapy, either with or without another drug called tislelizumab-jsgr. HER2 is a protein that can cause cancer cells to grow and divide very fast. Ziihera works by targeting and attaching to two different spots on the HER2 protein. By blocking these proteins, the medicine helps stop cancer cells from growing and helps the body’s immune system destroy them.
Why Was Ziihera Approved?
The approval of Ziihera was based on results from a large clinical study called HERIZON-GEA-01. The trial included 914 adult patients with advanced HER2-positive GEA. Patients were split into groups to compare Ziihera combination treatments against standard therapy with trastuzumab and chemotherapy. In the study, patients who received Ziihera plus tislelizumab-jsgr and chemotherapy lived for a median of 26.4 months, compared to 19.2 months for those on standard therapy. The Ziihera and tislelizumab group went a median of 12.4 months without their cancer getting worse, while the standard therapy group went 8.1 months. Patients who took Ziihera with chemotherapy alone also lived longer without disease progression compared to standard treatment. Diarrhea was the most common side effect seen across treatment groups, but it was managed with preventive medicines and supportive care.
What Do I Need to Know About Ziihera?
Ziihera is given as an intravenous (IV) infusion into a vein by a healthcare provider. Infusions are given every two or three weeks depending on the treatment plan. Your healthcare provider will give you medicine 30 to 60 minutes before each treatment to lower the chance of having an infusion reaction. You will also need to take diarrhea medicine during your first cycle of care to help control loose stools. Severe diarrhea is a major safety risk with Ziihera. Diarrhea can lead to a severe loss of fluids and body salts, which can be life-threatening. You must tell your healthcare provider right away if you get new or worsening loose stools. Ziihera can also cause heart problems by lowering how well your heart pumps blood. Your healthcare provider will test your heart function before and during your treatment. Tell your healthcare provider if you have a history of heart issues or if you are pregnant or breastfeeding. Ziihera can cause severe harm to a fetus. If you are able to get pregnant, you must take a pregnancy test before starting Ziihera and use effective birth control during treatment and for four months after their last dose. Other common side effects include nausea, vomiting, feeling tired, loss of appetite, rash, low blood potassium levels, and tingling in your hands or feet.
