Experimental Drug Shows Promise in Reducing Lymphedema Swelling

Scientists at Stanford University are making progress on a potential first-in-its-kind drug to treat lymphedema, a chronic condition characterized by fluid buildup and swelling, primarily in the arms or legs, which affects an estimated 10 million Americans.

Currently, there is no cure for lymphedema, nor are there medications specifically approved for its treatment. Patients typically rely on manual lymphatic drainage, compression garments, exercise, and in severe cases, surgery. These existing treatments can be labor-intensive and may only reduce swelling by up to 50 percent.

Promising Trial Results

A new study involving 23 patients with lymphedema in their legs explored the efficacy of acebilustat, an experimental anti-inflammatory drug. Participants took the medication once daily for a year. Researchers observed a 4.7 percent average decrease in leg volume, indicating a significant reduction in swelling. Beyond volume reduction, patients reported improvements in skin thickness, scarring, and overall quality of life, including reduced limb heaviness and increased self-confidence.

Ultrasound scans on 20 participants revealed changes in tissue density and structure, suggesting the drug may help address long-term damage caused by the condition. The study, published in Scientific Reports, involved adults with stage two lymphedema, an advanced stage where swelling is resistant to simple remedies.

Participants were, on average, 46 years old and slightly overweight. About 57 percent were women, and a similar percentage had lymphedema in one limb. Approximately two-thirds of participants had primary lymphedema, meaning it was not caused by external factors like cancer treatment. They continued their usual self-care treatments alongside the experimental drug.

How Acebilustat Works

The drug targets inflammation by inhibiting leukotriene B4 (LTB4), a molecule found in higher concentrations in lymphedema patients that contributes to inflammation. Lymphedema occurs when the lymphatic system, responsible for draining excess fluid from tissues, is impaired. This impairment can stem from damage to the lymphatic system due to cancer treatments, infections, or injuries, known as secondary lymphedema, or from improper development of the lymphatic system, often genetic, known as primary lymphedema.

Patient Experience

Matthew Holbreich, who has lived with lymphedema for 23 years, described the experimental drug as a "life-changing" prospect. He noted significant improvements in his leg volume and skin smoothness since starting acebilustat, calling it the "most significant breakthrough for lymphedema treatment in my lifetime."

Safety and Next Steps

The clinical trial reported no major side effects. Two participants experienced elevated liver enzymes, which normalized after discontinuing the medication. Two others had a single instance of cellulitis, a bacterial skin infection, which was successfully treated with antibiotics.

Dr. Stanley Rockson, the lead study author and professor at Stanford University School of Medicine, expressed hope that acebilustat could eventually supplement or even replace current self-care measures. The research team has initiated a phase 2 trial to compare acebilustat against a placebo in patients with arm lymphedema. If these trials continue to show promise, the team plans to seek approval from the Food and Drug Administration (FDA).