Real-World Clinical Outcomes of Ivermectin and Mebendazole in Cancer Patients
Published April 7, 2026 | Version v1
Abstract
Background: Drug repurposing offers a pathway to identify accessible, low-toxicity cancer therapies. Ivermectin and mebendazole have demonstrated multi-target anti-cancer activity in preclinical models, including the inhibition of cancer cell proliferation and the targeting of cancer stem cells. This paper evaluates real-world patient-reported outcomes, safety, and adherence in a cohort of cancer patients utilizing this combination protocol.
Methods: We analyzed a prospective observational cohort of 197 cancer patients who were prescribed ivermectin and mebendazole off-label through a telemedicine platform by licensed U.S. healthcare providers. Participants received compounded oral capsules containing 25 mg ivermectin and 250 mg mebendazole. As part of a clinical program evaluation, data were collected via voluntary, standardized digital surveys at baseline and at approximately 6-month follow-up. Of the initial cohort (N = 197), baseline characteristics, including cancer type and disease status, were assessed. A total of 122 participants completed the follow-up survey (61.9% response rate) to evaluate self-reported cancer outcomes, medication adherence, and adverse events. 95% confidence intervals (CI) were calculated for primary outcome measures using the Wilson score method. Dose-stratified analyses for outcomes and safety were conducted using Chi-square statistics.
Results: The cohort represented a diverse clinical profile of cancer patients, with mean age of 67 years and nearly balanced sex distribution (52.3% male, 47.7% female). Cancer types included prostate (27.9%), breast (18.3%), lung (8.6%), colon (5.1%), urologic (4.6%), pancreatic (3.0%), liver (2.5%), gynecologic (2.5%), and hematologic (2.5%) malignancies. At enrollment, participants had a median duration since initial diagnosis of 1.2 years, with 37.1% experiencing active disease progression. At 6-month follow-up, medication adherence was high with 86.9% of participants completing the full initial 90-capsule ivermectin-mebendazole prescription and 66.4% remaining on the protocol at 6 months. The Clinical Benefit Ratio (CBR) was 84.4% (95% CI: 77.0–89.8%). Notably, 48.4% (95% CI: 39.7–57.1%) of the cohort reported the strongest positive outcomes, consisting of regression (15.6%; 95% CI: 10.2–23.0%) or no current evidence of disease (NED, 32.8%; 95% CI: 25.1–41.5%). Disease stability was reported to be maintained in 36.1% (95% CI: 28.1–44.9%) of participants, while 15.6% (95% CI: 10.2–23.0%) reported disease progression. While 25.4% reported mild side effects (primarily gastrointestinal), 93.6% of those affected continued treatment through minor dose adjustments. Some participants reported concurrent conventional therapies, including chemotherapy (27.9%), radiation therapy (21.3%), and surgery (19.7%), as well as adjunctive interventions such as supplement use (49.2%), dietary modification (37.7%), and other integrative approaches.
Conclusions: In this prospective real-world cohort, the combination of ivermectin and mebendazole was associated with high rates of self-reported clinical benefit, with nearly half of participants reporting tumor regression or no current evidence of disease across a heterogeneous population of cancer patients. These findings provide a compelling clinical signal that these well-tolerated, repurposed agents may offer therapeutic benefit. However, given the observational design, reliance on self-reported outcomes, and potential for selection bias and uncontrolled confounding, these findings should be interpreted as hypothesis-generating. Urgent prospective, randomized, placebo-controlled clinical trials are warranted to validate these observations and further define optimal dosing strategies.
18 page PDF of paper also attached
https://zenodo.org/records/19455636