Therini Bio has dosed the first patient in a Phase 1b trial of THN391, a monoclonal antibody targeting the inflammatory epitope on fibrin, for early Alzheimer’s disease (AD) in patients with vascular risk factors. The study will evaluate safety, pharmacokinetics, and explore early efficacy signals using biomarkers, MRI imaging, and cognitive assessments. Initial data are expected in mid-2026.
This trial initiation marks an important step in Therini’s strategy to tackle neuroinflammation, a core driver of neurodegenerative diseases like AD, through a vascular-focused approach. While amyloid and tau remain dominant targets in AD drug development, Therini’s focus on fibrin reflects a growing recognition of the role vascular dysfunction plays in disease progression. This strategic choice positions the company to capitalize on an emerging therapeutic area with less crowded competition than the amyloid/tau space.
Targeting fibrin’s inflammatory epitope offers a potentially novel mechanism to disrupt the chronic neuroinflammation implicated in neuronal damage. Preclinical data suggest THN391 can protect against neuronal degeneration by blocking inflammatory cascades triggered by toxic fibrin deposits. If these findings translate to humans, THN391 could offer a new avenue for treating AD, especially in patients with pre-existing vascular risk factors, a population often excluded from other AD trials.
The trial design reflects the complexities and evolving understanding of AD. Inclusion of vascular risk factors recognizes the interplay between vascular health and neurodegeneration. The use of multiple biomarkers and imaging endpoints underscores the need for a more nuanced assessment of treatment effects beyond traditional cognitive measures. This approach aligns with broader industry trends toward incorporating more sensitive and objective endpoints in neurodegenerative disease trials.
Moving forward, Therini’s success hinges on demonstrating a clear link between fibrin modulation, neuroinflammation reduction, and clinically meaningful improvement in cognitive function. The Phase 1b data will be critical in validating the target engagement and establishing a foundation for later-stage trials. However, translating early biomarker changes into long-term cognitive benefits remains a significant hurdle in AD drug development, and Therini will need to carefully consider these challenges as it plans its Phase 2/3 strategy. Further, competition is heating up in the vascular-focused AD space, and Therini will need to differentiate its approach to attract further investment and partnership opportunities.
Jon Napitupulu is Director of Media Relations at The Clinical Trial Vanguard. Jon, a computer data scientist, focuses on the latest clinical trial industry news and trends.
