Partner Therapeutics’ Bizengri has received FDA approval for advanced cholangiocarcinoma driven by NRG1 gene fusions, marking the first approved therapy for this ultra-rare genetic driver. Partner said it acquired U.S. rights from Merus in 2024. The approval expands options for patients with a molecularly defined subset where treatment has historically been limited. For companies active in precision oncology, the decision reinforces demand for therapies targeting validated oncogenic fusions and other rare molecular events. The FDA approval also adds to the pipeline momentum around bispecific antibodies and other targeted biologics for genetically stratified populations. Follow-on commercialization strategy and further label expansions will be the next key datapoints for investors. Clinicians and payers will likely focus on testing workflows and the accuracy of companion diagnostics or FDA-authorized assays needed to identify eligible patients for NRG1 fusion status.