Pronunciation: HER-sess-ee
Generic name: trastuzumab-strf
Dosage form: single-dose vial for intravenous infusion
Drug class: HER2 inhibitors

Medically reviewed by Carmen Pope, BPharm. Last updated on May 24, 2024.

What is Hercessi?

Hercessi (trastuzumab-strf) is the 6th biosimilar to Herceptin to be granted FDA approval and may be used to treat certain types of HER2+ (Human Epidermal Growth Factor Receptor 2-Positive) cancers, specifically:

• HER2-overexpressing breast cancer
• HER2-overexpressing gastric or gastroesophageal junction adenocarcinoma that has spread (metastasized).

Your healthcare provider will use an FDA-approved test to determine if Hercessi is the right treatment for you.

Hercessi is a targeted treatment, not chemotherapy, because it targets cancers with large amounts of receptor proteins called HER2. HER2 is thought to send signals to cells telling them to grow and divide rapidly, causing tumors to form. By targeting and attaching to these receptors, Hercessi is thought to inhibit the growth and cell division of human tumor cells that overexpress HER2 and also tell the body’s immune system to destroy the cell. Normal cells also have HER2, but less of it, so Hercessi can affect normal cells, causing side effects.

Hercessi was approved as a biosimilar to Herceptin on April 25, 2024. A biosimilar means it is approved based on data demonstrating that it is highly similar to an FDA-approved biological product, known as a reference product (in this case, Herceptin), and that there are no clinically meaningful differences.

Hercessi side effects

Tell your healthcare provider immediately or seek emergency medical help if you have signs of an allergic or administration-related reaction such as dizziness, nausea, chills, fever, vomiting, diarrhea, hives, pain, headache, swelling under the skin, breathing problems, shortness of breath, or chest pain. Some side effects may occur during the injection, or in the days afterward. Tell your healthcare provider right away, even if these symptoms occur a few days later.

Hercessi can cause serious side effects (see warnings below). Call your doctor at once if you have:

• new onset or worsening shortness of breath or cough
• a light-headed feeling, like you might pass out or loss of consciousness
• severe headache, blurred vision, pounding in your neck or ears
• blisters or ulcers in your mouth, red or swollen gums, trouble swallowing
• heart problems--pounding heartbeats, palpitations, dizziness, swelling in your lower legs, rapid weight gain, feeling short of breath
• low blood cell counts--fever, chills, tiredness, skin sores, easy bruising, unusual bleeding, pale skin, cold hands and feet, feeling light-headed or
• signs of tumor cell breakdown--tiredness, weakness, muscle cramps, nausea, vomiting, diarrhea, fast or slow heart rate, tingling in your hands and feet or around your mouth.
• swelling of the ankles/legs or the face, or weight gain of more than 5 pounds in 24 hours.

Common side effects of Hercessi may include:

• heart problems
• nausea, diarrhea, weight loss
• headache
• trouble sleeping, feeling tired, fatigue
• low blood cell counts
• rash
• fever, chills, cough, or other signs of infection
• mouth sores or mucosal inflammation
• altered sense of taste or
• cold symptoms such as stuffy nose, sinus pain, and sore throat
• low platelet counts.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to Accord BioPharma Inc. at 1-866-941-7875 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

Related/similar drugs

Warnings

Hercessi may exacerbate chemotherapy-induced neutropenia (low levels of neutrophils [a type of white blood cell] caused by cancer treatments).

Hercessi can cause heart failure, especially if you have heart disease or if you are also receiving certain other cancer medicines (such as daunorubicin, doxorubicin, epirubicin, or idarubicin). Your healthcare provider will assess your heart function before treatment and monitor you throughout.

Serious and fatal infusion reactions and pulmonary toxicity have been reported with trastuzumab infusions, including bronchospasm, anaphylaxis, angioedema, interstitial pneumonitis, or acute respiratory distress syndrome. Reactions usually occur during or immediately following the infusion. Your healthcare provider will monitor you during the infusion.

Hercessi can cause harm to an unborn baby and result in oligohydramnios (a reduction in the levels of amniotic fluid), and incomplete lung development, which can be fatal. Women of childbearing potential should use effective contraception.

Before taking

Tell your doctor if you have experienced an infusion reaction or hypersensitivity reaction to trastuzumab, or its biosimilars such as Herceptin, Herzuma, Kanjinti, Ontruzant, Hercessi, or Trazimera, or any of the inactive ingredients in the vial.

Hercessi is only administered to eligible patients identified as having HER2 protein overexpression and HER2 gene amplification using an FDA-approved test specific for breast or gastric cancers by laboratories with demonstrated proficiency.

Before taking Hercessi, tell your doctor if you:

• have allergies
• have preexisting heart disease, a heart attack, congestive heart failure, or other heart problems
• have problems with your lungs or with breathing
• have low white blood cell counts
• have had chemotherapy treatment before
• are pregnant, may become pregnant, or intend to become pregnant
• are breastfeeding.

Pregnancy

You may need to have a negative pregnancy test before starting this treatment. Do not use Hercessi if you are pregnant.

Hercessi may result in the death of an unborn baby or birth defects. Females with childbearing potential should use effective contraception while receiving Hercessi and for 7 months after the last dose. If you inadvertently become pregnant while receiving trastuzumab or within 7 months after your last dose, tell your doctor right away.

Breastfeeding

It is unknown if Hercessi passes into human milk. It may not be safe to breastfeed while using this medicine and for up to 7 months after your last dose. Ask your doctor about any risks.

How is Hercessi administered?

Hercessi is administered as an intravenous infusion by a healthcare provider.

• Hercessi is usually given once every week or every 1 to 3 weeks. Follow your doctor's dosing instructions very carefully.
• This medicine must be given slowly, and the infusion can take 30 to 90 minutes depending on the stage of the cycle and type of cancer you have.
• Do not administer as an IV push or bolus. Do not mix with other drugs, although it may be given alongside other drugs (as a separate infusion). Hercessi should not be substituted for or with ado-trastuzumab emtansine.

You may need frequent medical tests to be sure this medicine is not causing harmful effects. Your cancer treatments may be delayed based on the results.

Your heart function may need to be checked before and during treatment with Hercessi. You may also need heart function testing every 6 months for 2 years after your last dose of this medicine.

Hercessi is usually given for 52 weeks, or until your body no longer responds to the medication.

What happens if I miss a dose?

Call your doctor for instructions if you miss an appointment for your Hercessi.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while receiving Hercessi?

Follow your doctor's instructions about any restrictions on food, beverages, or activity.

What other drugs will affect Hercessi?

Other drugs may affect Hercessi, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.

Patients who receive anthracycline during Hercessi treatment or within 7 months of stopping Hercessi are at increased risk of heart dysfunction.

Hercessi can have long-lasting effects on your heart, especially if you receive other cancer medicines, such as daunorubicin, doxorubicin, epirubicin, or idarubicin). For at least 7 months after your last dose of trastuzumab, tell any doctor who treats you that you have used Hercessi.

This is not a complete list of interactions. See the Hercessi Package Insert for more information.

Ingredients

Active: trastuzumab-strf 150mg in a single-dose vial for reconstitution.

Each vial must be reconstituted with 7.4 mL of Sterile Water for Injection (SWFI) (not supplied) to yield a single-dose solution containing 21 mg/mL trastuzumab-strf that delivers 7.15 mL (150 mg trastuzumab-strf). This is then added to an infusion bag containing 250 mL of 0.9% Sodium Chloride Injection.

Storage

Refrigerate at 2°C to 8°C (36°F to 46°F) in the original carton until the time of reconstitution. Do not freeze, do not shake.

Manufacturer

Accord BioPharma Inc.

Hercessi Biosimilars

Biosimilar and interchangeable products are biological products that are highly similar to and have no clinically meaningful differences from the reference product.

Reference products

These are biological products that have already been approved by the FDA, against which biosimilar products are compared. There is 1 for Hercessi.

Herceptin biosimilar products

Biosimilar products can only be dispensed in place of the reference product if the healthcare provider specifically prescribes the biosimilar product by name.

Pharmacy laws for biosimilar prescribing may vary by state

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Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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