A team at ETH Zurich has identified a small molecule that slowed Alzheimer’s-like disease in mice and significantly extended their lives. The compound, known for now as “compound 10,” not only reduced hallmark brain changes but also improved memory performance in multiple animal models. Researchers now see it as a potential first-in-class drug candidate, although it remains years away from human use.
The findings suggest that calming a single overactive enzyme in the brain might blunt several damaging processes at once. That possibility is energizing scientists who have grown frustrated with treatments that only modestly clear amyloid plaques yet do little for patients’ day-to-day function.
What changed in ETH Zurich’s latest Alzheimer’s drug experiments
The ETH Zurich group focused on an enzyme called 17-beta-hydroxysteroid dehydrogenase type 10, or HSD10, which is located in mitochondria and helps regulate energy metabolism. In Alzheimer’s disease this enzyme becomes overactive and starts to disrupt mitochondrial function, according to the team’s mechanistic work described in ETH Zurich communications. Rather than targeting amyloid or tau directly, the scientists designed a molecule that tempers HSD10 activity and restores a healthier balance inside neurons.
The resulting candidate, compound 10, was tested in several mouse models that develop amyloid deposits, tau pathology, or both. In these animals the drug reduced the accumulation of amyloid-beta and tau aggregates in the brain and eased inflammatory responses in microglia, according to preclinical data summarized by ScienceDaily. It also appeared to normalize mitochondrial function, which is increasingly viewed as a central driver of neurodegeneration rather than a side effect.
Behavioral testing showed that treated mice performed better in memory and learning tasks than untreated controls. In maze experiments and object recognition tests, animals that received compound 10 retained information longer and navigated more efficiently, results that were highlighted in a detailed report on compound 10. These improvements suggest that the drug did not simply clear pathological proteins but helped preserve neural circuits that support cognition.
Perhaps the most striking finding came from lifespan analyses. In one Alzheimer’s-prone mouse line, chronic dosing with compound 10 extended survival by roughly one third compared with untreated littermates, according to experimental summaries shared through project updates. Longer life on its own does not guarantee better quality, yet in this case the survival gains occurred alongside measurable cognitive benefits and reduced brain pathology.
Mechanistic studies in cell cultures supported the in vivo results. When neurons were exposed to toxic amyloid-beta, compound 10 reduced oxidative stress and prevented the collapse of mitochondrial membranes. Researchers traced this protection to a direct interaction between the molecule and HSD10, which dampened the enzyme’s aberrant activity without shutting it down entirely, as described in a mechanistic overview on new Alzheimer’s discovery. This partial inhibition approach is intended to avoid the side effects that can come from fully blocking a metabolic enzyme that cells also need for normal function.
Why the ETH Zurich compound matters in the Alzheimer’s race
Alzheimer’s research has been dominated for decades by attempts to remove amyloid plaques or prevent their formation. Several antibodies that target amyloid have now reached patients, yet their clinical impact remains limited and they carry safety concerns related to brain swelling and microbleeds. The ETH Zurich work points to a different strategy that aims upstream at a mitochondrial enzyme that influences multiple pathological cascades at once.
By focusing on HSD10, the researchers are effectively treating mitochondrial dysfunction as a core feature of Alzheimer’s rather than a downstream consequence. In the mouse studies, compound 10 not only lowered amyloid-beta and tau but also improved synaptic health and reduced markers of oxidative damage, according to aggregated findings presented on a single enzyme. This multi-target impact is appealing in a disease that likely arises from several interacting failures rather than a single toxic protein.
The survival data in mice also set compound 10 apart from many earlier candidates. Extending lifespan by about one third in a rigorous Alzheimer’s model suggests that the intervention is altering the course of disease rather than simply masking symptoms. For families facing a progressive, fatal condition, a therapy that both slows cognitive decline and adds meaningful time would represent a significant shift from current options that mostly manage behavior or slightly delay worsening.
The ETH Zurich team emphasizes that compound 10 is still at the preclinical stage. Safety in humans, optimal dosing, and potential interactions with other medications remain unknown. Even so, the molecule’s design as a small, brain-penetrant compound could make it easier to manufacture and administer than large antibody therapies, a point highlighted in summaries of the group’s medicinal chemistry program on experimental drug coverage.
For the broader Alzheimer’s field, the work adds weight to a growing view that metabolic and mitochondrial pathways are promising drug targets. Other groups have explored interventions that modulate glucose metabolism, insulin signaling, or mitochondrial biogenesis, but few have tied those efforts to such clear changes in both pathology and lifespan in animal models. The ETH Zurich findings suggest that carefully tuning enzymes like HSD10 might deliver more durable benefits than approaches that focus solely on amyloid clearance.
The research also arrives at a moment when regulators and funders are more open to alternative mechanisms. As experience accumulates with existing anti-amyloid drugs, clinicians are looking for treatments that can be combined with those antibodies or potentially replace them for some patients. A small molecule that targets mitochondrial dysfunction might fit naturally into combination regimens, especially if it proves safe and convenient to use over long periods.
What comes next for ETH Zurich’s compound 10 and similar candidates
The immediate priority for the ETH Zurich group is to move compound 10 through the remaining preclinical steps that are required before human testing. That work includes detailed toxicology in multiple species, assessments of long term dosing, and studies of how the drug is absorbed, distributed, and cleared. According to project updates shared through recent releases, the team is also refining formulations to ensure consistent brain exposure with oral administration.
Parallel efforts are focused on biomarkers that could track HSD10 activity in patients. To evaluate the drug in early clinical trials, researchers will need measurable indicators that compound 10 is hitting its target and normalizing mitochondrial function. Work described in ETH Zurich reports includes looking for metabolic signatures in cerebrospinal fluid and imaging markers that reflect mitochondrial health or oxidative stress in specific brain regions.
If those preparations succeed, the first-in-human studies would likely begin with healthy volunteers to assess safety and pharmacokinetics, followed by small trials in people with early-stage Alzheimer’s or mild cognitive impairment. Given the complex biology involved, researchers will probably combine cognitive testing with imaging and fluid biomarkers to detect early signs of benefit long before any clear change in daily function emerges.
Beyond compound 10 itself, the ETH Zurich findings are spurring interest in related molecules that interact with HSD10 or neighboring mitochondrial pathways. Medicinal chemists are already exploring analogs that might offer improved potency or selectivity, building on the structure activity relationships described in technical summaries linked through neuroscience coverage. A family of compounds could eventually provide options tailored to different stages of disease or to patients with specific genetic backgrounds.
There is also a broader strategic question for the field: how to integrate mitochondrial modulators with existing treatments. One scenario would pair a drug like compound 10 with an amyloid antibody, with the former stabilizing neuronal metabolism while the latter removes extracellular plaques. Another possibility is combining HSD10 inhibitors with lifestyle interventions that support mitochondrial health, such as structured exercise programs or dietary changes, to test whether a multipronged approach yields additive benefits.
