Exploring Ivermectin’s Anti-Cancer Potential
Ivermectin, primarily known for its anti-parasitic properties, has garnered attention for its potential role in cancer treatment. Approved for human use in 1987 to treat parasitic infestations such as river blindness and scabies, scientific inquiry now explores its anti-cancer capabilities.
The idea of ivermectin acting against cancer cells stems from laboratory observations. These suggest it can interfere with several cellular processes crucial for cancer progression, including cell proliferation, migration, and survival. This potential effect has led to studies exploring its mechanisms of action in various cancer types.
One mechanism involves ivermectin’s potential to induce programmed cell death in cancer cells, specifically apoptosis and autophagy. Apoptosis is a regulated process of cell self-destruction, while autophagy involves the cell recycling its own damaged components. Ivermectin appears to trigger excessive autophagy, pushing cancer cells towards self-destruction by blocking pathways like PAK1/Akt.
Ivermectin may also disrupt mitochondrial function, which is critical for the high energy demands of rapidly growing cancer cells. It inhibits mitochondrial complex I, leading to metabolic collapse in cancer cells. Additionally, ivermectin may target cancer stem cells and could potentially reverse multidrug resistance in some cancer cells.
Pre-Clinical Research: Lab and Animal Studies
Pre-clinical investigations, involving in vitro (cell culture) and in vivo (animal model) studies, have explored ivermectin’s anti-cancer activity. These studies represent an early stage of research, providing insights into potential mechanisms and efficacy. A significant body of evidence from these settings suggests ivermectin can inhibit cancer cell growth and induce cell death.
In cell culture experiments, ivermectin has demonstrated anti-proliferative effects and induced apoptosis in various cancer cell lines. These include breast, colon, ovarian, leukemia, glioblastoma, lung adenocarcinoma, and prostate cancer cells. For instance, ivermectin inhibited glioblastoma cell proliferation and induced apoptosis.
Animal models, particularly mice, have also provided evidence of ivermectin’s anti-tumor effects. Studies in tumor-bearing mice show ivermectin can reduce tumor size and weight, sometimes at doses comparable to clinically feasible concentrations. For example, in a mouse model, ivermectin enhanced anti-PD1 therapy, leading to improved tumor regression.
These pre-clinical findings highlight ivermectin’s ability to modulate specific signaling pathways frequently dysregulated in cancer. It also appears to induce mitochondrial dysfunction and oxidative stress in cancer cells. However, results from lab and animal studies do not directly guarantee efficacy or safety in humans due to inherent differences.
Human Trials and Regulatory Stance
Despite promising pre-clinical findings, human clinical trials investigating ivermectin for cancer treatment are limited. There is a notable gap between extensive laboratory research and conclusive large-scale human clinical evidence. The majority of scientific publications on ivermectin and cancer are pre-clinical.
Only one active phase 1/2 clinical trial is testing ivermectin with immunotherapy drugs for metastatic triple-negative breast cancer (TNBC). This trial aims to evaluate side effects, optimal dose, and combined effectiveness in shrinking tumors. While expected to conclude by 2026, positive results would still necessitate further phase 3 testing.
Preliminary results from an early abstract of this phase 1/2 study, involving eight evaluable patients, showed one patient with stable disease, one with a partial response, and six experiencing disease progression. These early human data do not yet provide strong evidence of ivermectin’s standalone efficacy in cancer. The National Cancer Institute (NCI) does not support ivermectin as a “cure for cancer.”
Major health organizations, including the U.S. Food and Drug Administration (FDA) and the World Health Organization (WHO), state ivermectin is not an approved cancer treatment. They do not recommend it for this purpose outside of controlled clinical trials. The FDA has only approved ivermectin tablets for specific parasitic infections and topical formulations.
Risks of Unproven Use
Using ivermectin for cancer treatment outside of approved clinical settings carries significant risks. Self-medication with unproven treatments can lead to adverse health outcomes and may delay or interfere with effective, evidence-based cancer care. This delay can result in worse prognoses for patients.
Higher doses of ivermectin, sometimes suggested for off-label use in cancer, can lead to more severe side effects than those with approved parasitic treatments. Common side effects include headache, muscle aches, dizziness, nausea, vomiting, and diarrhea. At elevated doses, individuals may experience serious issues like confusion, mental status changes, balance problems, seizures, coma, and even death.
There is also concern about possible drug interactions between ivermectin and conventional cancer therapies or other medications. For example, ivermectin can interact with blood thinners, increasing the risk of excessive bleeding. The lack of data on the long-term, daily ivermectin use further highlights these risks.