Biosimilar Ontruzant Now Available for Breast Cancer, Gastric Cancer Treatment

Ontruzant is supplied in 150 mg single-dose vials and 420 mg multidose vials.

Samsung Bioepsis announced the launch of Ontruzant® (trastuzumab-dttb), a biosimilar to Herceptin® (trastuzumab; Genentech), in the US.

Ontruzant, an HER2/neu receptor antagonist, is indicated for:

  • Adjuvant treatment of HER2 overexpressing node positive or node negative (ER/PR negative or with 1 high risk feature breast cancer) as part of a treatment regimen consisting of doxorubicin, cyclophosphamide, and either paclitaxel or docetaxel; as part of a treatment regimen with docetaxel and carboplatin; or as a single agent following multi-modality anthracycline based therapy. 
  • In combination with paclitaxel for first-line treatment of HER2-overexpressing metastatic breast cancer, and as a single agent, for treatment of HER2-overexpressing breast cancer in patients who have received 1 or more chemotherapy regimens for metastatic disease.
  • In combination with cisplatin and capecitabine or 5-fluorouracil, for the treatment of patients with HER2-overexpressing metastatic gastric or gastroesophageal junction adenocarcinoma who have not received prior treatment for metastatic disease.

Prior to treatment, HER2 testing using an FDA-approved companion diagnostic for a trastuzumab product should be performed. Information on tests for the detection of HER2 protein overexpression and HER2 gene amplification is available here. The product should not be substituted for or with ado-trastuzumab emtansine

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Ontruzant is supplied in 150mg single-dose vials and 420mg multidose vials. The wholesale acquisition cost is approximately $1325 for the 150mg single-dose vial and $3709 for the 420mg multiple-dose vial, which does not include discounts to payers, providers, distributors and other purchasing organizations.

The product will be marketed and distributed in the US by Merck.

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