Alzheimer’s disease (AD) is most commonly associated with the pathological hallmarks of amyloid-beta and tau. However, mounting evidence suggests that damage to the genome, in the form of DNA breaks, may also play an important role in disease progression.
Neurons are long-lived and rarely replaced, making them particularly susceptible to accumulating DNA damage over time. Studies have shown that DNA double-strand breaks (DSBs) appear early in the course of AD, alongside chronic neuroinflammation, making both processes attractive targets for therapies aimed at slowing or modifying the disease.
In a new study, neuroscientists at King’s College London have demonstrated that KCL-286, a first-in-class, oral small molecule, can reduce neuronal DNA damage and dampen neuroinflammation in a mouse model of AD. Notably, the compound has already completed Phase 1 safety and tolerability studies in humans, having originally been developed for spinal cord injury. That prior clinical progress could significantly accelerate its path toward proof-of-concept trials in patients with AD.
Beyond amyloid and tau
For decades, AD drug development has largely focused on removing amyloid-beta plaques or preventing the build-up of tau tangles. While these proteins are defining features of the disease, treatments that target amyloid have shown only modest clinical benefits, prompting researchers to explore other biological processes.
Increasing attention has turned to pathways linked to neuroinflammation and DNA damage. In particular, retinoic acid receptors (RAR) and retinoid X receptors (RXR), proteins involved in the body's vitamin A signaling pathway, are known to underpin synaptic plasticity and adult neurogenesis, while also modulating inflammatory and amyloid‐clearance pathways.
Rather than controlling a single disease process, it regulates multiple pathways that are disrupted across both nerve injury and neurodegenerative diseases.
—Jonathan Corcoran, King’s College London
KCL-286 activates RAR-beta, a master regulator of genes central to repairing and maintaining the nervous system. “Rather than controlling a single disease process, it regulates multiple pathways that are disrupted across both nerve injury and neurodegenerative diseases,” Jonathan Corcoran, senior author and neuroscientist at King’s College London, told DDN. “These include extracellular matrix remodeling, synaptic dysfunction, metabolic dysfunction, neuroinflammation, and neuronal damage.”
In this study, activating RAR-beta reduced neuronal DNA damage and dampened glial activation, a key driver of neuroinflammation. By acting upstream of multiple pathological processes, the drug could restore several disease-relevant pathways simultaneously, rather than targeting a single hallmark of AD.
Repairing damage
Early intervention is widely considered critical in neurodegenerative disease, as the brain’s endogenous repair mechanisms become increasingly exhausted over time. However, AD is often diagnosed only after significant pathology has already developed.
To address this clinical reality, the King’s team tested KCL-286 in a late-stage mouse model with established amyloid plaques — and still observed evidence of brain repair.
“That’s encouraging because it suggests there may be a therapeutic window even after disease pathology has developed,” Corcoran said. “We also know that KCL-286 activates pathways involved in the resolution and clearance of pathology, so there is reason to believe the drug may support the brain's ability to deal with the disease process as well as repair the damage it causes.”
Lowering development risk
One of the most significant hurdles in AD drug development is the leap from preclinical models into human studies — a step where many candidates fail due to safety or tolerability issues. KCL-286 has already crossed that threshold.
The compound completed a Phase 1 study in healthy volunteers, with no drug-related adverse events reported at exposures predicted to be relevant for neurodegenerative disease. “That substantially reduces development risk because we already have human safety and pharmacokinetic data,” said Corcoran.
The next step, he suggested, could be a relatively small proof-of-concept that would determine whether the biological repair mechanisms seen in preclinical models are activated in patients — an early but crucial signal of therapeutic potential.
Broader implications
While the current focus is AD, the researchers believe the implications of this approach may extend further. Many neurological disorders have distinct causes but share common consequences, including DNA damage and chronic inflammation.
“By enhancing the brain’s own repair mechanisms, KCL-286 has the potential to be relevant across a range of neurodegenerative and nerve injury conditions,” Corcoran said. If successful, it could help shift the field toward therapies that restore neural resilience — rather than chasing individual pathological targets one by one.
