FDA Approves Trastuzumab Biosimilar to Treat Forms of HER2-Overexpressing Cancer

The FDA has approved a 150 mg dosage of trastuzumab-strf (Hercessi, Accord BioPharma Inc), a biosimilar, for the treatment of HER2–over-expressing breast and gastric or gastroesophageal junction adenocarcinoma. This approval marks the first FDA-approved biosimilar from Accord BioPharma.¹

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"The approval of HERCESSI—our first biosimilar to be approved in the US—marks an important milestone for Accord BioPharma in our efforts to improve access for patients," said Chrys Kokino, US president of Accord, in a news release. "Because breast and gastric cancers are among the most common types of cancer and cancer can have a high-cost burden for patients, there is a need to provide these patients with additional treatment options that may be more affordable, such as biosimilars."¹

Trastuzumab is indicated for adjuvant breast cancer, metastatic breast cancer, and gastric cancer, all of which express HER2. The study authors noted that HER2 cancers are typically aggressive cancer types that display tolerability to targeted treatment. Trastuzumab aids this development, as it binds and inactivates the HER2 receptor, which then slows down cell replication.¹

In a previous study that assessed tucatinib (Tukysa; Seagen) with trastuzumab emtansine (T-DM1), the results displayed a median progression-free survival (PFS) of 9.5 months, compared to 7.4 months with a placebo among individuals with HER2-positive, locally advanced, or metastatic breast cancer.²

Earlier this month, the FDA has approved indications for fam-trastuzumab deruxtecan-nxki (Enhertu; Daiichi Sankyo and AstraZeneca) for the treatment of unresectable or metastatic HER2-positive solid tumors.³

The new biosimilar approval was granted based on analytical, pre-clinical, and clinical data—which included 3 studies that showed similarities in safety, efficacy, and quality between the trastuzumab originator product and the biosimilar.¹

The studies included 2 phase 1 studies (HLX02-HV01 and HLX02-HV02) that compared pharmacokinetics (PK) of a single dose among healthy volunteers, and a phase 3 study (HLX02-BC01) that assessed the safety comparability with docetaxel in HER2-overexpressing metastatic breast cancer. The study authors noted that the PK comparability, efficacy, and safety in each study followed FDA biosimilar guidance.¹

The most common adverse reactions with trastuzumab-strf among individuals with metastatic breast cancer were fever, nausea, and vomiting. Infusion reactions included diarrhea, infections, increased cough, headache, fatigue, dyspnea, rash, neutropenia, anemia, and myalgia. Additionally, the most common adverse reactions among individuals with metastatic gastric cancer were neutropenia, diarrhea, fatigue, anemia, stomatitis, weight loss, upper respiratory tract infections, fever, thrombocytopenia, mucosal inflammation, nasopharyngitis, and dysgeusia, according to study authors.¹

References

1. Accord BioPharma, Inc. Announces U.S. Food & Drug Administration Approval of HERCESSI™ (trastuzumab-strf), a biosimilar to Herceptin® (trastuzumab) for the Treatment of Several Forms of HER2-Overexpressing Cancer. PR Newswire. News release. April 29, 2024. Accessed April 29, 2024. https://www.prnewswire.com/news-releases/accord-biopharma-inc-announces-us-food--drug-administration-approval-of-hercessi-trastuzumab-strf-a-biosimilar-to-herceptin-trastuzumab-for-the-treatment-of-several-forms-of-her2-overexpressing-cancer-302129508.html.

2. Tucatinib, Trastuzumab Combination Improves Progression-Free Survival in HER2+, Locally Advanced or Metastatic Breast Cancer. Pharmacy Times. News release. December 7, 2023. Accessed April 29, 2024. https://www.pharmacytimes.com/view/tucatinib-trastuzumab-combination-improves-progression-free-survival-in-her2-locally-advanced-or-metastatic-breast-cancer.

3. FDA Approves Fam-Trastuzumab Deruxtecan-nxki for Unresectable or Metastatic HER2-Positive Solid Tumors. Pharmacy Times. News release. April 6, 2024. Accessed April 29, 2024. https://www.pharmacytimes.com/view/fda-approves-fam-trastuzumab-deruxtecan-nxki-for-unresectable-or-metastatic-her2-positive-solid-tumors.