FDA
Ziihera (zanidatamab-hrii) approved for biliary tract cancer
Brand name: Ziihera
Generic name: zanidatamab-hrii
Manufacturer: Jazz Pharmaceuticals
Approval date: November 20, 2024
FDA granted accelerated approval to Ziihera (zanidatamab-hrii), a bispecific HER2-directed antibody, for adults with previously treated, unresectable or metastatic HER2-positive (IHC 3+) biliary tract cancer (BTC), as detected by an FDA-approved test.*
According to the Prescribing Information, zanidatamab-hrii induces complement-dependent cytotoxicity (CDC), antibody-dependent cellular cytotoxicity (ADCC), and antibody-dependent cellular phagocytosis (ADCP), all of which lead to tumor growth inhibition and cell death.
*FDA also approved VENTANA PATHWAY anti-HER-2/neu (4B5) Rabbit Monoclonal Primary Antibody as a companion diagnostic device to aid in identifying patients with BTC who may be eligible for treatment with Ziihera.
Efficacy
Approval was supported by data from the phase 2b HERIZON-BTC-01 (NCT04466891), an open-label multicenter, single-arm trial involving 62 patients with unresectable or metastatic HER2-positive (IHC3+) BTC. Patients were required to have received ≥1 prior gemcitabine-containing regimen in the advanced disease setting. The major efficacy outcome measures were objective response rate (ORR) and duration of response (DOR). ORR was 52% (95% CI: 39, 65) and median DOR was 14.9 months (95% CI: 7.4, not estimable).
Safety
The prescribing information contains a boxed warning for embryo-fetal toxicity. The most common adverse reactions (≥20% of patients) in the clinical trial were diarrhea, infusion-related reactions, abdominal pain, and fatigue.
Recommended dose
The recommended dose of zanidatamab-hrii is 20 mg/kg administered as an IV infusion q2wks until progression or unacceptable toxicity.
Sources:
FDA. (2024, November 20). FDA grants accelerated approval to zanidatamab-hrii for previously treated unresectable or metastatic HER2-positive biliary tract cancer. [Press release]. https://www.fda.gov/drugs/resources-information-approved-drugs/fda-grants-accelerated-approval-zanidatamab-hrii-previously-treated-unresectable-or-metastatic-her2
Jazz Pharmaceuticals: Ziihera (zanadatamab-hrii) [Package insert]. U.S. Food and Drug Administration website. https://www.accessdata.fda.gov/drugsatfda_docs/label/2024/761416s000lbl.pdf
Jazz Pharmaceuticals. (2024, November 20). Jazz Pharmaceuticals Announces U.S. FDA Approval of Ziihera® (zanidatamab-hrii) for the Treatment of Adults with Previously Treated, Unresectable or Metastatic HER2-positive (IHC 3+) Biliary Tract Cancer (BTC). [Press release]. https://investor.jazzpharma.com/news-releases/news-release-details/jazz-pharmaceuticals-announces-us-fda-approval-ziiherar