Partner's Bizengri is first drug for rare, aggressive cancer
Partner Therapeutics' Bizengri has been approved for a new indication, a rare form of bile duct cancer, just two days after being awarded a Commissioner's National Priority Voucher (CNPV) from the FDA.
The voucher was awarded to Bizengri (zenocutuzumab) as a second-line treatment for NRG1 fusion-positive cholangiocarcinoma on 6th May, and cleared for marketing on 8th May, when it became the first FDA-approved therapy for this ultra-rare, aggressive cancer.
"Patients with this ultra-rare type of cancer desperately need new treatment options," said FDA Commissioner Marty Makary, who is rumoured to be at risk of losing his job, in a statement.
"Through the national priority voucher pilot programme, the FDA is accelerating therapies for rare diseases with unmet medical needs, reviewing applications in significantly shortened timelines."
Bizengri, originally developed by Merus Therapeutics, is a bispecific HER2 and HER3-targeting antibody that won accelerated approval in 2024 for NRG1+ non-small cell lung cancer and pancreatic adenocarcinoma. It was licensed to Partner in the US later that year, and has picked up orphan drug and breakthrough designations from the FDA for the cholangiocarcinoma indication.
The news stems from a cohort of the single-arm energy trial involving 19 patients with the bile duct cancer, which revealed a 36.8% overall response rate and a duration of response ranging from 2.8 months to 12.9 months. Partner submitted its marketing application for the new use in the middle of April.
"For patients facing cholangiocarcinoma, innovation and timely diagnosis can make a profound difference," said Stacie Lindsey, chief executive of the Cholangiocarcinoma Foundation patient organisation.
"While this approval applies to a small subset of patients, every new targeted therapy expands hope and underscores the critical importance of biomarker testing and continued research," she added.
"The FDA's recognition of this potential treatment underscores […] the importance of expanding access to comprehensive biomarker testing so patients can be matched to the most appropriate therapies as early as possible." NRG1 mutations can currently only be identified based on genome sequencing.
While the approval will be celebrated by the patient community and the clinicians who care for them, the rapid decision after the granting of the voucher may fuel ongoing concerns that the CNPV programme risks undermining review standards and public confidence in the FDA's processes.
Critics have suggested the scheme's selection process is opaque, it lacks statutory backing, and could be vulnerable to political interference, and could compromise patient safety.
The FDA has scheduled a public meeting on 4th June (brought forward from 12th June) to discuss the CNPV's eligibility criteria, the voucher selection process, and other elements of the programme.
