As reported on BioSpace, the U.S. Food and Drug Administration (FDA) has approved Partner Therapeutics’ bispecific antibody Bizengri for adults with cholangiocarcinoma harboring an NRG1 gene fusion, marking a significant development for a patient population with limited treatment options. The decision follows closely on the heels of the therapy receiving a Commissioner’s National Priority Voucher (CNPV), underscoring the agency’s push to accelerate access to treatments for serious and rare diseases.
Bizengri targets HER2 and HER3 receptors and is designed to disrupt signaling pathways linked to tumor growth in cancers driven by NRG1 gene fusions. The therapy had previously secured accelerated approval in December 2024 for select patients with non-small cell lung cancer as well as pediatric cases of adenocarcinoma characterized by the same genetic alteration. With this latest authorization, its label now extends to adults with cholangiocarcinoma whose disease has progressed after prior systemic therapy.
NRG1 gene fusions are exceptionally rare in cholangiocarcinoma—occurring in fewer than 1% of patients—but are associated with more aggressive disease. Notably, Bizengri becomes the first FDA-approved treatment specifically indicated for this molecular subtype, addressing a critical unmet medical need in a difficult-to-treat cancer.
The approval is supported by data from a small, single-arm clinical study involving 19 patients. In that trial, the overall response rate reached 36.8%, with some responses lasting from under three months to nearly 13 months. While limited by its size, the study provided sufficient evidence of activity in this ultra-rare population to justify regulatory clearance.
The rapid approval timeline highlights the impact of the FDA’s CNPV initiative. Introduced in mid-2025, the program is intended to reward companies that align with federal priorities such as improving drug affordability and strengthening domestic manufacturing. In return, qualifying therapies receive significantly shortened review timelines. Bizengri represents the seventh product to gain approval under this pathway.
FDA Commissioner Marty Makary emphasized that the program is designed to expedite therapies addressing serious unmet needs in rare diseases. In this case, Partner Therapeutics submitted its supplemental application shortly before receiving the voucher, and approval followed within days of the award.
Despite its early successes, the CNPV program has also drawn scrutiny. Industry stakeholders and policymakers have raised concerns about the lack of clarity around eligibility criteria and decision-making processes. Critics argue that limited transparency makes it difficult for companies to determine whether their products may qualify, potentially reducing the program’s predictability and broader impact.
Questions about the program’s consistency have been amplified by recent reports of internal disagreements within the FDA regarding certain applications. In one notable instance, a drug developer reportedly requested removal from the program after disputes over its therapy’s risk-benefit profile.
Even so, Bizengri’s approval illustrates the potential of targeted therapies combined with expedited regulatory pathways to bring new options to patients with rare, genomically defined cancers. As precision medicine continues to evolve, such approaches are expected to play an increasingly prominent role in oncology drug development—particularly for populations that have historically lacked effective treatments.
The longer-term effectiveness and safety of Bizengri in cholangiocarcinoma will likely require further study, but the current approval offers a new, much-needed option for a small group of patients with limited alternatives.
