FDA approves Poherdy, first biosimilar of Perjeta, to treat HER-positive breast cancer

The FDA has approved Poherdy (pertuzumab), an HER2/neu receptor antagonist, for the treatment of adults with HER2-positive breast cancer, according to a recent news release. The decision marks a significant milestone, as Poherdy is both the first FDA-approved biosimilar to Perjeta (pertuzumab) and the first interchangeable biosimilar to the therapy. With this approval, clinicians will gain an additional option for patients requiring targeted HER2-directed treatment, potentially expanding access and lowering costs across oncology care.

Poherdy is approved for two key indications. The first is for use in combination with trastuzumab and docetaxel for adults with HER2-positive metastatic breast cancer who have not received prior anti-HER2 therapy or chemotherapy for metastatic disease. This combination has long been a foundational approach for HER2-positive metastatic breast cancer, targeting the overexpressed HER2 protein while simultaneously disrupting cancer cell proliferation.

The second indication is for the treatment of adults with HER2-positive early breast cancer when used in combination with trastuzumab and chemotherapy. Eligible patients include those with tumors greater than 2 cm in diameter or those who are node positive. Poherdy may be used in neoadjuvant settings to help shrink tumors and improve surgical outcomes or in adjuvant settings for patients who remain at high risk of recurrence. This dual indication aligns Poherdy with existing Perjeta treatment pathways across both early-stage and metastatic disease.

Approximately 15% to 20% of all breast cancers are classified as HER2-positive, meaning tumor cells overexpress the HER2 protein, which drives faster growth and more aggressive disease progression. The introduction of HER2-targeted monoclonal antibodies transformed the prognosis for this subset of patients, and the availability of cost-saving biosimilar options may help further broaden access to these life-extending therapies.

The recommended initial dose of Poherdy mirrors that of Perjeta: an 840-mg loading dose administered as a 60-minute intravenous infusion, followed by 420-mg maintenance doses infused every three weeks over 30 to 60 minutes. These dosing parameters support consistency for clinicians accustomed to using the reference product.

The FDA’s approval was based on a totality-of-evidence review, including extensive analytical comparisons, pharmacokinetic evaluations, clinical immunogenicity assessments and supportive clinical data in patients with breast cancer. Together, these data demonstrated that Poherdy is highly similar to Perjeta with no clinically meaningful differences in safety, purity, or potency. Importantly, Poherdy also met additional standards required to earn an interchangeable designation, meaning it may be substituted for Perjeta at the pharmacy level where state law permits.

The safety of Poherdy was evaluated using evidence drawn from the reference product’s clinical program, including data from the landmark AFFINITY and CLEOPATRA trials. Across indications, the most common adverse reactions include diarrhea, nausea and alopecia, which is consistent with the safety profile of Perjeta.

The prescribing information for Poherdy carries a boxed warning for left ventricular dysfunction and embryo-fetal toxicity, mirroring the warnings associated with the reference biologic. Additional safety considerations include risks of infusion-related reactions, hypersensitivity reactions and anaphylaxis, underscoring the importance of careful monitoring during administration. Serious reactions may require discontinuation and appropriate medical management.

With Poherdy’s approval, the FDA continues expanding the biosimilar landscape in oncology, reinforcing competition in biologic markets while supporting long-term affordability and access for patients with HER2-positive breast cancer.