A modified parasite treatment originally approved by the FDA for tapeworms has shown promise in mice against endometriosis, a painful condition affecting roughly 190 million people. Published in August in Advanced Healthcare Materials, the nanotechnology-based approach targets rogue immune cells, potentially pointing toward non-surgical therapies.
Endometriosis remains a clinical failure for the millions of people who live with it. Characterized by uterine tissue growing outside the uterus, the chronic inflammatory disease brings severe abdominal and pelvic pain, fertility struggles, and a stubborn resistance to lasting solutions. Standard approaches lean heavily on surgery and hormone therapy. Yet nearly half of patients who undergo surgical removal of lesions see them return within five years, while hormonal treatments often suppress the menstrual cycle alongside side effects like mood swings, hot flushes, depression, and osteoporosis. Because the condition can only be definitively diagnosed through surgery, many cases go underdiagnosed and undertreated.
How Nanotechnology Restructures Niclosamide
To bypass the limitations of current options, researchers turned to an unexpected candidate: niclosamide, a medication approved by the US Food and Drug Administration to treat parasitic infections like tapeworms. While earlier work demonstrated that niclosamide possesses anti-inflammatory properties capable of attenuating endometrial tissue growth, the drug suffers from poor water solubility. Patients would need high doses to achieve therapeutic effects, leading to cramps, nausea, and appetite loss—making standard formulations impractical for managing a chronic condition.
To solve this hurdle, investigators collaborated with nanomedicine specialists to redesign the drug. They attached niclosamide to a molecule known as a dendrimer to improve how it dissolves in blood. They also equipped the modified compound with a folate receptor designed to home in on a specific group of rogue immune cells found within endometrial lesion tissue.
Basically, the dendrimer is like the Uber, the folate is like the GPS, and the drug is like the passenger.
Anjali Sharma, nanomedicine specialist at the University of Michigan
That molecular carshare design ensures the medication remains inactive while circulating systemically until it reaches diseased cells, where it is slowly released over a two-week period.
Results in Animal Models and Expert Reactions
In mouse models, a single injection of the targeted formulation directly affected endometrial tissue, lowering inflammation, reducing pain, and slowing or entirely stopping the growth of new lesions. Researchers and outside specialists have greeted these preliminary laboratory findings with cautious optimism.
The drug is attached in such a way that when it is in systemic circulation, nothing happens until it goes inside the diseased cells.
Anjali Sharma, nanomedicine specialist at the University of Michigan
Elise Courtois, a molecular biologist at the Jackson Laboratory in Farmington, Connecticut, hailed the study as a beautiful first step
toward non-surgical, non-hormone-based alternatives. Kanako Hayashi, a reproductive biologist at Washington State University in Pullman who previously worked on a 2016 study examining niclosamide’s anti-inflammatory impact on endometrial tissue that had been implanted into mice, noted that replicating these findings in humans could represent a “breakthrough” in endometriosis treatment.
Other specialists agree that repositioning existing compounds offers a pragmatic path forward. Ioannis Simitsidellis, a postdoctoral researcher at the University of Edinburgh’s Centres for Reproductive Health and Inflammation Research who was not involved in the work, pointed out that there is potential in repurposing of drugs that have been tested in clinical trials to see if they would be effective in endometriosis.
Next Steps Toward Clinical Trials
Despite the encouraging laboratory outcomes, significant hurdles remain before the treatment can be evaluated in people. Mice do not menstruate or develop endometriosis, meaning animal models cannot fully replicate the human condition.
The research team intends to scale up testing by examining the modified drug in larger sample sizes. If those subsequent animal studies prove successful, the researchers hope to advance toward formal human clinical trials.