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Herceptin Hylecta Dosage

Dosage form: injection, solution
Drug class: HER2 inhibitors

Medically reviewed by Last updated on Oct 9, 2023.

Patient Selection

Select patients based on HER2 protein overexpression or HER2 gene amplification in tumor specimens [see Indications and Usage (1) and Clinical Studies (14)]. Assessment of HER2 protein overexpression and HER2 gene amplification should be performed using FDA-approved tests specific for breast cancer by laboratories with demonstrated proficiency. Information on the FDA-approved tests for the detection of HER2 protein overexpression and HER2 gene amplification is available at:

Improper assay performance, including use of suboptimally fixed tissue, failure to utilize specified reagents, deviation from specific assay instructions, and failure to include appropriate controls for assay validation, can lead to unreliable results.

Recommended Doses and Schedules

HERCEPTIN HYLECTA is for subcutaneous use only. HERCEPTIN HYLECTA has different dosage and administration instructions than intravenous trastuzumab products. Do not administer intravenously.

Do not substitute HERCEPTIN HYLECTA for or with ado-trastuzumab emtansine.

The recommended dose of HERCEPTIN HYLECTA is 600 mg/10,000 units (600 mg trastuzumab and 10,000 units hyaluronidase) administered subcutaneously over approximately 2-5 minutes once every three weeks.

No loading dose is required. No dose adjustments for patient body weight or for different concomitant chemotherapy regimens are required.

Duration of treatment

Patients with adjuvant breast cancer should be treated with HERCEPTIN HYLECTA for 52 weeks or until disease recurrence, whichever occurs first; extending treatment in adjuvant breast cancer beyond one year is not recommended.

Patients with metastatic breast cancer (MBC) should be treated with HERCEPTIN HYLECTA until progression of disease.

Missed Dose

If one dose is missed, it is recommended to administer the next 600 mg/10,000 units dose (i.e. the missed dose) as soon as possible. The interval between subsequent HERCEPTIN HYLECTA doses should not be less than three weeks.

Dosage Modification for Adverse Reactions

Cardiomyopathy [see Boxed Warning, Warnings and Precautions (5.1)]

Assess left ventricular ejection fraction (LVEF) prior to initiation of HERCEPTIN HYLECTA and at regular intervals during treatment. Withhold HERCEPTIN HYLECTA dosing for at least 4 weeks for either of the following:

  • ≥16% absolute decrease in LVEF from pre-treatment values
  • LVEF below institutional limits of normal and ≥10% absolute decrease in LVEF from pretreatment values.

HERCEPTIN HYLECTA may be resumed if, within 4–8 weeks, the LVEF returns to normal limits and the absolute decrease from baseline is ≤15%.

Permanently discontinue HERCEPTIN HYLECTA for a persistent (>8 weeks) LVEF decline or for suspension of HERCEPTIN HYLECTA dosing on more than 3 occasions for cardiomyopathy.

Administration and Storage

To prevent medication errors, it is important to check the vial labels to ensure that the drug being prepared and administered is HERCEPTIN HYLECTA and not ado-trastuzumab emtansine or intravenous trastuzumab.

HERCEPTIN HYLECTA should be administered by a healthcare professional.

Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit. Do not use vial if particulates or discoloration is present. Discard any unused portion remaining in the vial.

HERCEPTIN HYLECTA is for single use only. The 600 mg/10,000 units (600 mg trastuzumab and 10,000 units hyaluronidase) solution is a ready to use solution for injection which does not need to be diluted.

To avoid needle clogging, attach the hypodermic injection needle to the syringe immediately prior to administration followed by volume adjustment to 5 mL. HERCEPTIN HYLECTA is compatible with polypropylene and polycarbonate syringe material and stainless steel transfer and injection needles.

Prepare the dosing syringe in controlled and validated aseptic conditions. After the solution of HERCEPTIN HYLECTA is withdrawn from the vial and into the syringe, replace the transfer needle with a syringe closing cap. Label the syringe with the peel-off sticker.


The injection site should be alternated between the left and right thigh. New injections should be given at least 2.5 cm from the old previous site on healthy skin and never into areas where the skin is red, bruised, tender, or hard, or areas where there are moles or scars. During the treatment course with HERCEPTIN HYLECTA other medicinal products for subcutaneous administration should preferably be injected at different sites. The dose should be administered subcutaneously over approximately 2 to 5 minutes.


If the syringe containing HERCEPTIN HYLECTA is not used immediately, then the syringe can be stored in the refrigerator (2°C to 8°C) for up to 24 hours and subsequently at room temperature (20°C to 25°C) for up to 4 hours. Protect from light. Do not shake or freeze.

Frequently asked questions

Further information

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