Accord BioPharma, the U.S. specialty division of Intas Pharmaceuticals, has announced FDA approval for a 420mg strength of Hercessi (trastuzumab-strf), a biosimilar to Herceptin (trastuzumab). This approval expands the availability of a cost-effective treatment option for HER2-overexpressing breast and gastric cancers and paves the way for Accord BioPharma to launch its first biosimilar in the U.S. market in early 2025. Hercessi is indicated for adjuvant treatment of HER2-overexpressing breast cancer, metastatic breast cancer, and metastatic gastric or gastroesophageal junction adenocarcinoma.
Clinical Data Supporting Approval
The FDA's approval was based on a comprehensive data package, including analytical, preclinical, and clinical studies. These studies demonstrated that Hercessi is similar to Herceptin in terms of efficacy, safety, and quality. The data included results from two Phase 1 comparative single-dose pharmacokinetic trials in healthy subjects and a Phase 3 clinical efficacy and safety comparability study in patients with HER2-overexpressing metastatic breast cancer. The Phase 3 study was a double-blind, randomized trial evaluating Hercessi in combination with docetaxel (HLX02-BC01).
Mechanism of Action and Clinical Significance
HER2-overexpressing cancers are known for their aggressive nature but often respond well to targeted treatments. Hercessi works by binding to and inactivating the HER2 receptor, which slows down cell replication. This mechanism is crucial in managing the progression of HER2-positive cancers. According to Chrys Kokino, U.S. president of Accord, the company is committed to helping patients gain access to needed medicines and recognizes the promise of biosimilars in reducing the financial burden of oncologic therapies.
Safety Profile and Warnings
The safety profile of Hercessi is consistent with that of Herceptin. However, the prescribing information includes a boxed warning for cardiomyopathy, infusion reactions, embryo-fetal toxicity, and pulmonary toxicity. Specifically, trastuzumab products can result in cardiac failure, and decreased left ventricular ejection fraction (LVEF), with the greatest risk when administered with anthracyclines. Regular cardiac monitoring is recommended. The drug should be discontinued for anaphylaxis, angioedema, interstitial pneumonitis, or acute respiratory distress syndrome. Exposure to trastuzumab products during pregnancy can result in oligohydramnios, potentially leading to pulmonary hypoplasia and neonatal death; therefore, effective contraception is advised.
Strategic Implications and Future Prospects
Binish Chudgar, vice chairman and managing director of Intas Pharmaceuticals, emphasized that the FDA's approval of both strengths of Hercessi marks the beginning of Accord BioPharma's journey to bring a portfolio of biosimilars to the U.S. This move is expected to expand affordable treatment options for breast and gastric cancer patients. Accord BioPharma has also submitted biologics license applications for biosimilar versions of pegfilgrastim, filgrastim, and ustekinumab, indicating a robust pipeline of biosimilars aimed at addressing various medical needs.
Jason Zhu, executive director and CEO of Shanghai Henlius Biotech, the developer of Hercessi, highlighted that the approval represents an important step in meeting the needs of patients with innovative, high-quality, and affordable therapeutics.
