Hernexeos: Uses, Side Effects and Dosage

What HERNEXEOS is used for:

What is a Notice of Compliance with Conditions (NOC/c)?

A Notice of Compliance with Conditions (NOC/c) is a type of approval to sell a drug in Canada.

Health Canada only gives an NOC/c to a drug that treats, prevents, or helps identify a serious or life-threatening illness. The drug must show promising proof that it works well, is of high quality, and is reasonably safe. Also, the drug must either respond to a serious medical need in Canada, or be much safer than existing treatments.

Drug makers must agree in writing to clearly state on the label that the drug was given an NOC/c, to complete more testing to make sure the drug works the way it should, to actively monitor the drug’s performance after it has been sold, and to report their findings to Health Canada.

How HERNEXEOS works:

HER2 (ERBB2)-mutant non-small cell lung cancer (NSCLC) is a type of lung cancer caused by a change in the HER2 (ERBB2) gene. This change can make cancer cells grow and divide quickly.

HERNEXEOS is a treatment that targets the HER2 protein. It works by attaching to and blocking this protein’s signal. This helps slow down or stop the growth of cancer cells driven by the HER2 (ERBB2) mutation.

The ingredients in HERNEXEOS are:

Medicinal ingredient: zongertinib

Non-medicinal ingredients: Colloidal silicon dioxide, croscarmellose sodium, ferric oxide (yellow), glycerol mono and dicaprylocaprate, hypromellose acetate succinate, mannitol, microcrystalline cellulose, polyvinyl alcohol, sodium stearyl fumarate, sodium lauryl sulfate, talc, and titanium dioxide

HERNEXEOS comes in the following dosage form:

Tablets: 60 mg

Do not use HERNEXEOS if:

• You are allergic to zongertinib, or any other ingredients in HERNEXEOS or its container.

To help avoid side effects and ensure proper use, talk to your healthcare professional before you take HERNEXEOS. Talk about any health conditions or problems you may have, including if you:

• have or have had liver problems.
• have or have had heart problems.

Other warnings you should know about:

• Liver Problems:

  • Your healthcare provider will do blood tests to check your liver function during your treatment with HERNEXEOS. Tell your healthcare provider right away if you have any symptoms of a liver problem, which may include:

    • yellowing of your skin or the white part of your eyes (jaundice);
    • dark or brown (tea coloured) urine;
    • pain on the upper right side of your stomach area (abdomen);
    • bleeding or bruising more easily than normal;
    • feeling very tired.

• Diarrhea

  • HERNEXEOS may cause diarrhea (loose stools) during treatment. This may start within 1-2 weeks of treatment and can be severe or persistent.
  • If you get diarrhea during treatment, tell your healthcare professional. They may need to give you medicines to treat the diarrhea.

• Female Patients:

  Pregnancy and birth control

  • If you are able to get pregnant or think you are pregnant, there are specific risks you must discuss with your healthcare professional.
  • Your healthcare professional will do a pregnancy test before you start treatment with HERNEXEOS.
  • Avoid becoming pregnant while taking HERNEXEOS.

  • You should use an effective form of non-hormonal birth control during treatment with HERNEXEOS and for 10 days after your last dose.

    • Birth control methods that contain hormones (such as birth control pills, injections or transdermal system patches) may not work well during treatment with HERNEXEOS.
    • Talk to your healthcare professional about birth control methods that might be right for you during this time.
  • Tell your healthcare provider right away if you become pregnant or think you are pregnant while taking HERNEXEOS.

Breastfeeding

• Do NOT breastfeed during treatment and for 10 days after your last dose of HERNEXEOS. It is not known if HERNEXEOS passes into your breast milk.
• Talk to your healthcare professional about the best way to feed your baby during treatment with HERNEXEOS.

• Fertility in Females:

• HERNEXEOS may cause fertility problems in females, which may affect your ability to have children. Talk to your healthcare provider if this is a concern for you.
• Check-ups and testing:

• You will have regular visits with your healthcare professional before and during treatment with HERNEXEOS. They will:

  • Do blood tests to check your liver function. This will be done at the beginning of treatment, once every 2 weeks during the first 8 weeks of treatment, at week 12 and periodically as needed.
  • Do tests to monitor your heart before starting treatment and regularly during treatment as needed.
  • check for signs of side effects, including lung problems

Tell your healthcare professional about all the medicines you take, including any drugs, vitamins, minerals, natural supplements or alternative medicines.

The following may interact with HERNEXEOS:

• carbamazepine, phenobarbital or phenytoin, medicines used to treat seizures;
• prasugrel, medicine used to prevent heart attack or stroke;
• rifampicin, an antibiotic used to treat tuberculosis;
• rosuvastatin, medicine used to treat high cholesterol and prevent heart disease;
• sulfasalazine, medicine used to treat arthritis and ulcerative colitis;
• St. John’s Wort, a herbal medicine used to treat depression

How to take HERNEXEOS:

• Take HERNEXEOS exactly as your healthcare professional has told you. Check with your healthcare professional if you are not sure.
• Take HERNEXEOS one time a day, at the same time each day for as long as your healthcare professional has prescribed.

• Take HERNEXEOS with or without food.

• Swallow tablets whole with water.

Usual dose:

Your healthcare professional will decide on the best dose for you.

The usual dose is based on body weight:

• Patients weighing less than 90 kg: 120 mg (two 60 mg tablets)
• Patients weighing more than 90 kg: 180 mg (three 60 mg tablets)

Your dose will also depend on your current health, if you take certain other medications, or if you have certain side effects. Your healthcare professional will monitor your health throughout your treatment and may interrupt, reduce or stop your dose.

Overdose:

Missed dose:

If you miss a dose of HERNEXEOS by:

• less than 12 hours of your usual time, take it as soon as you remember.
• more than 12 hours of your usual time, skip the missed dose and take your next dose at your next scheduled time.

Possible side effects from using HERNEXEOS:

These are not all the possible side effects you may have when taking HERNEXEOS. If you experience any side effects not listed here, tell your healthcare professional.

Side effects may include:

• diarrhea
• rash
• increased liver function tests
• nausea, vomiting
• nail problems
• feeling tired
• muscle pain
• upper respiratory tract infection, such as a cold
• shortness of breath
• cough

HERNEXEOS may cause abnormal blood test results. Your healthcare professional will tell you if your blood tests are abnormal and if you need treatment to correct these side effects.

Serious side effects and what to do about them

If you have a troublesome symptom or side effect that is not listed here or becomes bad enough to interfere with your daily activities, tell your healthcare professional.

Reporting side effects

Storage:

• Store at 15 to 25°C. Store in the original container to protect from moisture. Keep the bottle tightly closed. Once opened, use within 3 months.
• Keep out of reach and sight of children.
• Do not use this medicine after the expiry date which is stated on the carton.
• Do not throw away any medicines via wastewater or household waste. Ask your pharmacist how to throw away medicines you no longer use. These measures will help protect the environment.

If you want more information about HERNEXEOS:

• Talk to your healthcare professional
• Find the full product monograph that is prepared for healthcare professionals and includes the Patient Medication Information by visiting the Health Canada Drug Product Database website (https://www.canada.ca/en/health-canada/services/drugs-health-products/drug-products/drug-product-database.html); the manufacturer’s website (https://www.boehringer-ingelheim.ca); or by calling 1-800-263-5103, extension 84633.

Date of Authorization: 2026-09-24