As the end of the year approaches, we reflect on the remarkable scientific discoveries made in 2025 across various fields, ensuring that all methodologies, including the use of animals, are integrated into the most contemporary biomedical research. 

Here is a selection of the most-read research news from 2025 from EARA’s website:

1) In Spain, researchers at CNIO and CSIC developed an ultra-thin light probe that can penetrate deeply into the brains of mice and detect changes caused by tumours or brain injuries.“This technology allows us to study the brain in its natural state without the need for prior alteration… The difference with existing technology is that we can now perform this analysis in a minimally invasive way, regardless of whether the tumour is superficial or deep,” said Manuel Valiente, senior author of the study published in Nature Methods, at CNIO.

2) A game-changing painkiller – the first in 30 years that is not based on potentially addictive opioids – was approved in February by regulators in the US. Suzetrigine, marketed as Journavx by Vertex Pharmaceuticals, is a new painkiller to treat acute pain. Animal studies with rats and mice were the first to show that suzetrigine could block pain signalling in the gastrointestinal tract. Many other similar studies, including those using monkeys, also examined its safety and effectiveness.

3) Researchers at the Weizmann Institute of Science, in Israel, discovered that human cells can naturally produce compounds that kill bacteria and fight infections in mice. The proteosome, a cellular waste disposal system, generates small protein fragments that have antibiotic action. This discovery, published in Nature, may open the door to future treatments that are alternatives to antibiotics in the fight against drug-resistant bacteria.

4) In August, a transplant of genetically altered pancreatic cells was tested for the first time in a human, allowing a patient with type 1 diabetes to produce their own insulin. In type 1 diabetes, a lifelong condition, the immune system destroys a type of pancreatic cell that makes insulin.

Researchers from Sana Biotechnology, a US-based company, used CRISPR gene editing technology to modify pancreatic cells, removing the proteins that trigger the immune system to recognise and attack them. The treatment was first tested in mice and monkeys. This year, it was given to a 42-year-old man with long-standing type 1 diabetes, in a first-in-human study led by EARA member Uppsala University. Four months after the procedure, the gene-edited transplanted cells were still producing insulin without provoking an immune response or significant side effects.

5) In September, uniQure announced a groundbreaking therapy for Huntington’s disease that slowed disease progression by 75% in human clinical trials.  

The therapy AMT-130 involves delivering a virus that instructs brain cells to block production of the huntingtin protein in Huntington’s patients. Accumulation of the defective huntingtin protein in the brain is a hallmark of the disease, as is motor impairment and cognitive decline.

“My patients in the trial are stable over time…, and one of them is my only medically retired Huntington’s disease patient who has been able to go back to work,” said Ed Wild, clinical researcher at University College London.

This breakthrough was only possible due to numerous years of preclinical research, including studies in brain cells from Huntington’s patients and studies using mice, pigs, rats and monkeys, essential to inform the design of the therapy and its efficacy.