Zanidatamab for HER2-Positive Biliary Tract Cancer Submitted to FDA

A novel drug has been submitted to the FDA via Biologics License Application.

A treatment for certain patients with biliary tract cancer, zanidatamab, has been submitted to the Food and Drug Administration (FDA) via a Biologics License Application, according to a news release from Jazz Pharmaceuticals, the manufacturer of the drug.

The pharmaceutical company hopes to have its drug approved by the FDA to treat patients with previously treated, unresectable, locally advanced or metastatic HER2-positive biliary tract cancer. The news release noted that, if approved, the drug will become the first HER2-targeted treatment specifically for patients with biliary tract cancer in the U.S.

A Biologics License Application can be submitted by drug companies to request permission to introduce a “biologic product into interstate commerce,” meaning across state borders across the U.S., according to the FDA.

"This important milestone brings us one step closer to delivering zanidatamab, a targeted treatment option, to patients living with HER2-positive [biliary tract cancer], a type of cancer that is associated with a five-year overall survival rate of less than 5%," said Dr. Rob Iannone, executive vice president, global head of research and development of Jazz Pharmaceuticals, in the news release.

Data from HERIZON-BTC-01, a phase 2b trial, was included in the Biologics License Application, the news release stated. The trial included patients who were previously treated for HER2-positive biliary tract cancer.

The primary endpoint (outcome measured at the end of a study to see if treatment worked) was the confirmed objective response rate (ORR) in Cohort 1 of the trial. The ORR is the percentage of patients whose tumors shrunk or disappeared after treatment, the National Cancer Institute states.

Findings from Cohort 1 from the phase 2b trial determined that patients had a 41.3% confirmed ORR, with an estimated median duration of response (how long the cancer responds to treatment) was 12.9 months.

The safety and efficacy of zanidatamab demonstrated a “manageable and tolerable safety profile, according to the release. Two patients in the trial experienced side effects, which led to discontinuation of the treatment. No life-threatening side effects or deaths were reported related to the treatment. Common side effects experienced by patients were diarrhea and infusion-related reactions

Currently, zanidatamab is being evaluated in HERIZON-BTC-302, a phase 3 trial for patients with HER2-positive biliary tract cancer. The trial includes approximately 286 patients, who were randomly assigned into two treatment arms. Patients received either zanidatamab plus standard-of-care chemotherapy or chemotherapy with or without a PD-1/PD-L1 inhibitor, such as Imfinzi (durvalumab) and Keytruda (pembrolizumab), according to the listing on ClinicalTrials.gov.

The goal of the trial is to measure progression-free survival (PFS) in patients whose tumors were checked for markers. PFS is referred to as the time when patients live without their cancer worsening or spreading, as defined by the National Cancer Institute.

Secondary goals of the trial are to identify PFS in all patients, overall survival as well as safety and effectiveness of zanidatamab. Overall survival is defined as the period from diagnosis when patients live, regardless of cancer status, according to the National Cancer Institute.

“Zanidatamab is a biparatopic HER2-targeted bispecific antibody that simultaneously binds two non-overlapping epitopes of HER2 resulting in multiple mechanisms of action,” Iannone said. “Second-line [biliary tract cancer] 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 3 trials in [first-line biliary tract cancer], [first-line] gastroesophageal adenocarcinoma, and previously treated breast cancer."

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