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

Summary

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. © 2025. The Author(s).

Authors Flores BN, Yu SB, Cohen IV, Fanok MH, Luan W, Maciuca RD, Sun LD, Tsai RM, Vissers M, Smits L, Bunte TM, Bakardjiev A, Balasundar S, Calvert MEK, Chin MY, Dobbins SK, Dowdle WE, Fang M, Heuberger JAAC, Ha CL, Huang F, Miyamoto T, Osipov M, Madrid San Martin L, Saund K, Tatarakis D, Vu AQ, Xiong C, Yeo GW, Groeneveld GJ, van den Berg LH, Dhuria S, Estrada AA, Jennings D, Sandmann T, Ho C, Scearce-Levie K, Yulyaningsih E, Walker AK, Di Paolo G, Kane LA, Troyer MD, Lewcock JW
Journal Nature communications
Publication Date 2025 Aug 18;16(1):7690
PubMed 40825784
PubMed Central PMC12361401
DOI 10.1038/s41467-025-63031-y

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