FDA Approves HER2 Test as Companion Diagnostic for Zanidatamab in Biliary Tract Cancer
The FDA approved the PATHWAY anti-HER2/neu (4B5) Rabbit Monoclonal Primary Antibody test as a companion diagnostic to assess HER2+ status in patients with BTC.
- PATHWAY anti-HER2/neu (4B5) Rabbit Monoclonal Primary Antibody has been approved by the FDA as a companion diagnostic for zanidatamab-hrii (Ziihera) to assess HER2-positive (HER2+) status in patients with biliary tract cancer (BTC).
- The agent will also help to identify those eligible for treatment with zanidatamab.
- This is the first and only FDA-approved companion diagnostic to aid in the assessment of HER2-positive status to identify patients with BTC who are eligible for zanidatamab.
The FDA has granted approval to the PATHWAY anti-HER2/neu (4B5) Rabbit Monoclonal Primary Antibody test as a companion diagnostic to assess HER2+ status in patients with BTC.1
This development enables the identification of patients who may benefit from treatment with zanidatamab and provides a more precise method for determining HER2 status.
The FDA granted accelerated approval to zanidatamab for the treatment of patients with previously treated, unresectable or metastatic HER2+ biliary tract cancer on November 20, 2024.2 Findings from the phase 2b HERIZON-BTC-01 trial (NCT04466891) supported this approval.
“This test is a step forward in furthering access to personalized medicine,” Jill German, head of the Pathology Lab at Roche Diagnostics, stated in a news release.1 “The prognosis for patients diagnosed with biliary tract cancer is poor, as very few treatment options exist. Now, these patients have access to the first standardized test that could make them eligible for targeted therapy, potentially improving clinical outcomes.”
This marks the first HER2-targeted treatment and companion diagnostic specifically approved by the FDA in this disease state.
About the HERIZON-BTC-01 Trial
HERIZON-BTC-01 enrolled 87 patients with HER2-amplified, locally advanced unresectable or metastatic biliary tract cancer, including gallbladder cancer and intra-/extra-hepatic cholangiocarcinoma. Patients were enrolled if they had received prior gemcitabine-containing therapy, and all patients were required to have centrally confirmed HER2 status on tissue samples.2
The primary end point of the study was confirmed overall response rate (cORR) by independent central review (ICR), and secondary end points were duration of response (DOR), disease control rate (DCR), progression-free survival, overall survival (OS), and safety.3
In cohort 1 of the phase 2b HERIZON-BTC-01 trial, which included 62 patients with HER2+ BTC with a median age of 64 years (range, 38-79), zanidatamab led to an ORR of 52% (95% CI, 39%-65%) and a median DOR of 14.9 months per ICR (95% CI, 7.4-not evaluable). Partial responses were seen in 30 patients and 2 patients had a complete response.2
For safety, the prescribing label for zanidatamab lists that in the 80-patient safety population, adverse events (AEs) occurring in at least 20% of patients were diarrhea, infusion-related reaction, abdominal pain, and fatigue.4 Serious AEs (SAEs) occurred in 53% of patients receiving zanidatamab. The most common SAEs were biliary obstruction (15%), biliary tract infection (8%), sepsis (8%), pneumonia (5%), diarrhea (3.8%), gastric obstruction (3.8%), and fatigue (2.5%). In this safety population, 2.5% of patients permanently discontinued zanidatamab due to an AE, and 1 patient treated with zanidatamab had a fatal AE.
HERIZON-BTC-302 (NCT06282575), an ongoing, confirmatory, phase 3 study, is now assessing treatment with zanidatamab plus standard-of-care (SOC) therapy in the frontline vs SOC therapy alone in patients with HER2-positive biliary tract cancer.1
REFERENCES
Roche receives FDA approval for first companion diagnostic to identify patients with biliary tract cancer eligible for HER2-targeted treatment with ZIIHERA. News release. Roche. November 25, 2024. Accessed November 25, 2024. https://tinyurl.com/5xbr67wj
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). News release. Jazz Pharmaceuticals. November 20, 2024. Accessed November 25, 2024. https://tinyurl.com/25msc7bp
Pant S, Fan J, Oh D-Y, et al. Zanidatamab in previously-treated HER2-positive (HER2+) biliary tract cancer (BTC): Overall survival (OS) and longer follow-up from the phase 2b HERIZON-BTC-01 study. J Clin Oncol. 2024;42(suppl 16):4091. doi:10.1200/JCO.2024.42.16_suppl.4091
Prescribing Label: ZIIHERA® (zanidatamab-hrii) for injection, for intravenous use. Initial U.S. approval: 2024. Accessed November 25, 2024. https://pp.jazzpharma.com/pi/ziihera.en.USPI.pdf
FDA Accepts BLA for Belantamab Mafodotin Combinations in R/R Multiple Myeloma
November 25th 2024The FDA has accepted the BLA for belantamab mafodotin in combination with bortezomib and dexamethasone, or pomalidomide and dexamethasone, in relapsed/refractory multiple myeloma, as supported by DREAMM-7 and DREAMM-8 data.
Read More
The FDA grants approval to revumenib (SNDX-5613) for a subgroup of acute leukemia, and dato-dXd moves into the final stage in NSCLC. We also cover expert updates from the 42nd Annual Chemotherapy Symposium Foundation in CLL, as well as other relevant insights on CML and multiple myeloma treatment.
Read More
