Repurposed Tapeworm Drug Shows Promise in Colon Cancer

Niclosamide modifies a signaling pathway crucial for the survival of colon cancer cells.

Despite improved treatment options for cancer, certain subtypes can be resistant to chemotherapy and biologic therapy. Patients with colon cancer that is unaffected by current therapies may have a new option through a repurposed drug, according to a press release from the Duke Cancer Institute.

Researchers reported that niclosamide, an anthelmintic used to treat tapeworms overseas, may be an effective therapy for colon cancer.

The team of researchers recently started a proof of principle study that investigates the drug’s efficacy in colon cancer. Thus far, 4 patients have enrolled in the study, which is expected to expand to 12 patients with colon cancer.

Currently, niclosamide is not distributed in the United States due to the availability of more effective treatments for tapeworms, but it is highly used around the world.

During the study, patients will take a 7-day course of the treatment prior to surgery. After surgery, the investigators will examine resected tissue to determine whether niclosamide affected the WNT-beta-catenin signaling pathway, according to Duke.

The researchers believe that niclosamide works by breaking down molecules in the pathway that drive proliferation and are prevalent among colon cancer cases. The authors report that it has been difficult to find drugs that can modify the WNT-beta-catenin pathway.

The investigators were working on different types of screening techniques for specific pathways when they came across niclosamide.

“[Researcher Wei] Chen[, PhD] was screening the WNT/beta-catenin pathway and he was going through the commercially available library of all FDA-approved drugs, and niclosamide came up as a hit and then we did additional work to show it really does have anti-cancer activity and isn’t not just a non-specific toxin,” said researcher Michael Morse, MD, FACP, MHS.

The investigators expect to see significant results during the clinical trial.

“We saw an impact on this pathway in mouse models, and we expect we’ll see this in the colon cancers of people as well,” Dr Morse said.

Positive study results could result in future clinical trials in patients with colon cancer, according to the release.

Niclosamide is commonly used around the world and is on the World Health Organization’s List of Essential Medicines. It is also known to have minimal side effects. The investigators do not expect there will be any significant safety issues when used among patients with colon cancer.

“It’s quite safe and millions of people in other parts of the world have taken it for tapeworm infections without any special monitoring,” Dr Morse concluded.