Experimental treatment restored movement and vision in mice with MS-like disease.
A new experimental drug has shown the ability to reverse some signs of multiple sclerosis (MS) damage in mice, raising hopes for treatments that could do more than slow the disease. Researchers at the University of Virginia Health System reported that the drug, called Kamuvudine K-9, helped restore movement and vision in animals affected by an MS-like condition. Current MS medicines mainly work to reduce inflammation and prevent future attacks. The new findings suggest that K-9 may also help repair some damage that has already occurred, although its effects in people remain unknown.
The experimental drug was developed by Jayakrishna Ambati, a physician and researcher at the University of Virginia. K-9 is related to a group of HIV medicines known as nucleoside or nucleotide reverse transcriptase inhibitors, often shortened to NRTIs. These medicines are already approved for treating HIV, but researchers have been studying whether they may also affect harmful inflammation linked to other illnesses. In the mouse experiments, K-9 helped protect nerve fibers and the myelin that surrounds them. Myelin acts like insulation around electrical wires, allowing signals to travel properly between the brain and the rest of the body. In MS, the immune system attacks this protective covering, disrupting communication and causing problems that can include weakness, vision changes, fatigue, and difficulty moving.
The team also tracked a blood marker called neurofilament light chain, or NfL. Higher levels of this marker can point to damage to nerve cells. In the treated mice, K-9 stopped NfL levels from rising, suggesting that the drug helped limit further harm to nerve tissue. Animals given an approved MS medicine did not regain as much function as those treated with K-9 in the reported experiments.
The researchers also examined health insurance records from more than three million people to study the use of NRTIs and MS. Their analysis found that people who used these HIV medicines had a 41% lower risk of developing MS. Among people already diagnosed with the disease, NRTI use was linked to a 36% lower yearly rate of relapses. These findings show an association, however, and do not prove that the medicines directly caused the lower rates.
MS is a long-term condition in which the immune system mistakenly attacks parts of the nervous system. It often begins between ages 20 and 40 and affects nearly one million people in the United States. Symptoms and disease patterns vary widely. Some people experience periods of worsening symptoms followed by remission, while others face a steady decline in movement or other abilities. Although available medicines can reduce flare-ups and slow disease activity, there is currently no cure.
Ambati’s team believes K-9 may work by blocking inflammasome activation, a process involved in inflammation. The researchers developed the compound as a possible alternative to existing NRTIs, with the hope that it could offer improved safety and effectiveness. K-9 is already being tested in clinical trials for certain eye conditions, including diabetic macular edema and thyroid eye disease. That work may help researchers learn more about its safety as they consider further studies.
The team stressed that the MS results come from animal research. More testing is needed to find out whether K-9 can safely produce similar benefits in people, and whether any regained movement or vision could last over time. The drug is also being considered for study in other illnesses involving nerve damage and inflammation, including amyotrophic lateral sclerosis, or ALS. Related compounds may be explored for conditions such as Alzheimer’s and Parkinson’s diseases, but their value for those disorders has not been established.
The findings were published in Science Translational Medicine. The researchers say the results provide a reason to continue studying K-9, while further clinical trials will be needed before it can be considered a treatment for people with MS.
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Experimental drug reverses multiple sclerosis damage in mouse model
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