National Cancer Institute Launches Preclinical Study of Ivermectin's Anticancer Properties

The National Cancer Institute has initiated a preclinical study to investigate ivermectin's potential as a cancer treatment, marking a controversial shift in research priorities that has alarmed career scientists at the federal agency.

NCI Director Anthony Letai announced the study during a January 30 event titled "Reclaiming Science: The People's NIH," stating that the institute decided to pursue research based on public interest rather than new scientific evidence. "There are enough reports of it, enough interest in it, that we actually did — ivermectin, in particular — did engage in sort of a better preclinical study of its properties and its ability to kill cancer cells," Letai said.

Study Details and Timeline

The preclinical study, conducted in laboratory settings before potential human trials, aims to assess whether the antiparasitic drug may be useful against cancer and to evaluate potential harms. Letai indicated that results should be available within a few months, though he did not elaborate on whether NCI scientists are conducting the research internally or if funding has been directed to outside institutions.

The FDA has approved ivermectin for treating parasitic worm infections in humans and has approved topical formulations for lice and rosacea. Two scientists involved in the drug's discovery won the Nobel Prize in 2015 for its success in treating certain parasitic diseases.

Scientific Community Response

The decision has generated significant concern among NCI researchers. "I am shocked and appalled," one NCI scientist said, speaking anonymously due to fear of retaliation. "We are moving funds away from so much promising research in order to do a preclinical study based on nonscientific ideas. It's absurd."

The scientist questioned whether sufficient initial evidence exists to justify spending taxpayer funds on investigating ivermectin's anticancer potential. A second NCI scientist noted that the notion that NIH was not open to investigating off-label drugs in cancer research is "ridiculous," adding "This is not a new idea they came up with."

Existing Research and Clinical Evidence

Previous laboratory research has demonstrated that ivermectin could have anticancer effects by promoting cell death and inhibiting tumor cell growth. "It actually has been studied both with NIH funds and outside of NIH funds," Letai acknowledged.

However, human clinical evidence remains limited. Preliminary data from a small clinical trial that administered ivermectin to patients with metastatic breast cancer in combination with immunotherapy found no significant benefit from adding ivermectin to the treatment regimen.

Clinical Concerns and Patient Safety

Physicians report regular inquiries from cancer patients about ivermectin, primarily driven by social media exposure. Jeffery Edenfield, executive medical director of oncology for South Carolina-based Prisma Health Cancer Institute, emphasized the limitations of preclinical research: "Many, many, many things work in a test tube. Quite a few things work in a mouse or a monkey. It still doesn't mean it's going to work in people."

Edenfield described persuading a patient to discontinue ivermectin use and noted that a colleague recently encountered a patient who decided "to forgo highly effective standard therapy in favor of ivermectin." He observed that patients often arrive at consultations "having largely already made up their mind" about alternative treatments.

The FDA has warned that large doses of ivermectin can be dangerous, with overdoses potentially causing seizures, comas, or death. A case report from Cincinnati Children's Hospital Medical Center detailed an adolescent patient with metastatic bone cancer who experienced ivermectin-related neurotoxicity after self-medicating based on social media posts, requiring emergency care for nausea, fatigue, and other symptoms.

Policy Context and Expectations

The study aligns with the Trump administration's "Make America Healthy Again" agenda, with NIH Director Jay Bhattacharya stating that the agency has "an obligation" to investigate treatments that generate significant public interest. "What you're hearing at the NIH now is an openness to ideas — even ideas that scientists would say, 'Oh, there's no way it could work' — but nevertheless applying rigorous scientific methods to those ideas," Bhattacharya said.

Despite initiating the research, Letai tempered expectations about potential outcomes. "At least on a population level," he said, "it's not going to be a cure-all for cancer."

The National Cancer Institute, HHS, and the Florida Department of Health did not respond to questions about funding amounts, study protocols, or related research initiatives.