Three follow-up efficacy trials for BIIB092 have been initiated based on these data. Two studies were in patients with 4R-tauopathy, including PASSPORT (NCT03068468), which enrolled 490 PSP patients, and the TauBasket study (NCT03658135), which enrolled 22 patients with diverse clinical syndromes including CBS, nfvPPA, MAPT, and TES. In December 2019, Biogen announced that PASSPORT would be stopped after an interim futility analysis showed no efficacy on primary or secondary endpoints, and the TauBasket study was terminated at the same time. A parallel trial in AD-related tauopathy, TANGO (NCT03352557) remains open, with a goal to enroll 654 patients for 76 weeks of treatment, with safety as a primary endpoint and CDR as a secondary endpoint, and this study is expected to run through 2024.
