Don Tracy, Associate Editor

Approval would mark first HER2-targeted therapy for biliary tract cancer in the United States.

Jazz Pharmaceuticals announced that it has completed its Biologics License Application (BLA) for zanidatamab, an investigational bispecific antibody treatment targeting HER2-positive metastatic(BTC). Aiming for accelerated approval, zanidatamab has the potential to be the first HER2-targeted therapy indicated for BTC in the United States. According to the company, the BLA was based on findings from the Phase IIb HERIZON-BTC-01 trial for zanidatamab. The primary study endpoint of confirmed objective response rate (cORR) by independent central review (ICR) was deemed a success, as the 80 enrolled patients demonstrated a cORR of 41.3%. The HERIZON-BTC-302 Phase III started recently and is currently in the process of enrollment.1
"This important milestone brings us one step closer to delivering zanidatamab, a targeted treatment option, to patients living with HER2-positive BTC, a type of cancer that is associated with a five-year overall survival rate of less than 5%," said Rob Iannone, MD, MSCE, EVP, global head, research and development, Jazz Pharmaceuticals, in a press release. "Zanidatamab is a biparatopic HER2-targeted bispecific antibody that simultaneously binds two non-overlapping epitopes of HER2 resulting in multiple mechanisms of action. Second line (2L) BTC represents the first of multiple indications we are evaluating and we are excited about zanidatamab's potential as a new option for multiple HER2-expressing cancers, with ongoing Phase III trials in 1L BTC, 1L gastroesophageal adenocarcinoma (GEA), and previously treated breast cancer."
Last June, Jazz Pharmaceuticals and Zymeworks presented data from the Phase IIb trial at the 2023 the American Society of Clinical Oncology (ASCO) annual meeting. Additionally, the results were published in The Lancet Oncology. Along with the results, the company showed data that demonstrated a consistently tolerable safety profile. Only two out of 87 patients experienced adverse events (AEs) that led to treatment discontinuation. The most common AEs were diarrhea and low-grade and infusion-related reactions.
Further, results found that zanidatamab provided a speedy and strong response as a treatment for patients with treatment-refractory HER2-amplified BTC.2
"With a confirmed ORR of 41.3 percent, median DOR of 12.9 months and median PFS of 5.5 months, these results for zanidatamab are a significant step forward for second-line treatment of HER2-amplified BTC, where current chemotherapy treatments have been reported to provide only a 5 to 15 percent ORR and median PFS of 1.4 to 4 months," said Shubham Pant, MD, professor, gastrointestinal medical oncology, investigational cancer therapeutics, The University of Texas MD Anderson Cancer Center, in a press release. "The HERIZON-BTC-01 trial advances an exciting field of oncology research where we can leverage next-generation sequencing on BTC patients to understand genomic markers of the disease and choose the appropriate targeted therapies for these patients."
According to the American Cancer Society, bile duct cancer is rare, with approximately 8,000 people in the United States receiving a diagnosis annually, both intrahepatic (inside the liver) and extrahepatic (outside the liver). It is also more common in Southeast Asia as a result of parasitic infection.3
“Bile duct cancer is seen mainly in older people, but it can occur in younger people,” reports the American Cancer Society. “The average age of people in the US diagnosed with cancer of the intrahepatic (inside the liver) bile ducts is 70, and for cancer of the extrahepatic (outside the liver) bile ducts it's 72.”