Interchangeable Biosimilar Approval: FDA Greenlights Poherdy as First to Perjeta

FDA Grants First Interchangeable Biosimilar Approval for HER2-Positive Breast Cancer Treatment

The U.S. Food and Drug Administration (FDA) has issued an interchangeable biosimilar approval for Poherdy (pertuzumab-dpzb) as the first biosimilar to Perjeta (pertuzumab), a monoclonal antibody targeting human epidermal growth factor receptor 2-positive (HER2-positive breast cancer). This interchangeable biosimilar approval allows pharmacy-level substitution under state laws, akin to generic drugs, which could improve patient access to more affordable options. Core data confirm Poherdy’s matching safety, efficacy, and indications to the reference product, including use with trastuzumab and docetaxel for metastatic breast cancer (MBC), and with trastuzumab plus chemotherapy for neoadjuvant and adjuvant therapy in high-risk early breast cancer.

Rigorous Analytical Matching Confirms Structural Similarity

Poherdy shows high similarity to Perjeta via detailed analytical evaluations, such as physicochemical testing and biological assays across various lots, verifying no meaningful differences in structure or function that could affect safety or efficacy. A pharmacokinetic (PK) study in healthy volunteers demonstrated similar exposure levels following a single intravenous dose. Meanwhile, a clinical trial in patients with early HER2-positive, hormone receptor-negative breast cancer during neoadjuvant treatment bolstered the case for this interchangeable biosimilar approval. These results underscore Poherdy’s role as a HER2/neu receptor blocker that inhibits ligand binding, triggers antibody-dependent cell-mediated cytotoxicity, and enhances anti-tumor effects alongside trastuzumab.

Evidence Base for Interchangeable Biosimilar Approval

The FDA’s review drew on robust scientific data, including in-depth quality assessments and comparative clinical results, to validate Poherdy as a biosimilar. Analytical comparisons covered properties like molecular weight (around 148 kDa) and composition (420 mg/14 mL solution with histidine, polysorbate 20, sorbitol, and water for injection at pH 6). The PK study revealed consistent linear pharmacokinetics, with median clearance of 0.24 L/day and a 18-day half-life, unchanged by factors like age, sex, ethnicity, or mild-to-moderate kidney issues. Complementing this were insights from key trials such as CLEOPATRA, NeoSphere, TRYPHAENA, BERENICE, and APHINITY, alongside the neoadjuvant study, forming a complete evidence package for interchangeability without safety risks from anti-drug antibodies.

Cost Savings and Market Shift from Interchangeable Biosimilars

This pioneering interchangeable biosimilar approval stands to cut costs for breast cancer therapies, where originators like Perjeta drive up expenses. Pharmacy substitution could ease patient copays and insurance burdens, boosting treatment adherence and availability for metastatic, neoadjuvant, or adjuvant regimens, while delivering comparable progression-free survival and overall survival rates from trial data. On a larger scale, it promotes competitive pricing and reimbursement changes in the biosimilars market, advancing affordable oncology options that preserve proven efficacy. For full details on the FDA’s announcement, review the official release.