Investigational eIF2B activator DNL343 modulates the integrated stress response in preclinical models of TDP-43 pathology and individuals with ALS in a randomized clinical trial
Brittany N. Flores, Seungyoon B. Yu, Isaac Cohen, Melania H. Fanok, Wei Luan, Romeo Maciuca, Linus D. Sun, Richard M. Tsai, Maurits F. J. M. Vissers, Lars Smits, Tommy M. Bunte, Anna I. Bakardjiev, Srijana Balasundar, Meredith Calvert, Marcus Y. Chin, Sarah Dobbins, William E. Dowdle, Meng Fang, Jules A. A. C. Heuberger, Connie Ha, Fen Huang, Takashi Miyamoto, Maksim Osipov, Lidia Madrid San Martin, Katie Saund, David Tatarakis, Anthony Q. Vu, Chenling Xiong, G Yeo, Geert Jan Groeneveld, Leonard H. van den Berg, Shyeilla V. Dhuria, Anthony A. Estrada, Danna Jennings, Thomas Sandmann, Carole Ho, Kimberly Scearce‐Levie, Ernie Yulyaningsih, Adam K. Walker, Gilbert Di Paolo, Lesley A. Kane, Matthew D. Troyer, Joseph W. Lewcock
Abstract
Neuronal TDP-43 aggregates are a hallmark ALS pathology. The integrated stress response (ISR) occurs downstream of TDP-43 pathology and may promote neurodegeneration. Here we demonstrate that a CNS penetrant small molecule eIF2B activator inhibits the ISR in cellular models of ALS and the brain of an inducible mouse model of TDP-43 pathology, where it transiently slowed progression of locomotor deficits and neurodegeneration. ISR activation was observed in ALS patient spinal cord and CSF. The investigational drug DNL343 was advanced into Phase 1 and Phase 1b randomized, double-blind, placebo-controlled trials in healthy and ALS participants, respectively (NCT04268784/NCT05006352); the primary objective in both studies was to investigate the safety and tolerability DNL343. DNL343 demonstrated a half-life supporting once-daily dosing and showed extensive CSF distribution. DNL343 was generally well tolerated and reduced ISR biomarkers in peripheral blood mononuclear cells and CSF of ALS participants. Therefore, DNL343 is a useful investigational drug to explore the effects of ISR inhibition in ALS models and individuals with neurological diseases. Flores et al. show that brain-penetrant eIF2B agonists suppress ISR activation in cellular and mouse models of ALS and reduce ISR biomarkers in humans, enabling further clinical studies of ISR inhibition in individuals with neurological diseases