Are there ongoing or completed European clinical trials testing ivermectin in oncology and what were their results?
This fact-check may be outdated. Consider refreshing it to get the most current information.
Executive summary
European investigators have moved ivermectin from petri dishes into a very small number of human studies, but robust evidence of benefit in cancer is lacking: a 2025 ASCO abstract reported a phase I/II trial of ivermectin plus the PD‑1 agonist balstilimab in metastatic triple‑negative breast cancer (trial NCT05318469) that found the combo “safe and well tolerated” with a modest clinical benefit rate in a heavily pretreated cohort (ASCO abstract) [1]. Multiple reviews and editorials in 2025 emphasize that clinical evidence in humans remains sparse and that, as of mid‑2025, there was essentially only one active cancer trial of ivermectin identified by reviewers [2] [3].
1. Small, early human trials have begun — but they’re exploratory
European and international groups have translated preclinical signals into at least one formal early‑phase human trial: a phase I/II study combining oral ivermectin with balstilimab for metastatic triple‑negative breast cancer was reported as an ASCO 2025 abstract (clinicaltrials.gov: NCT05318469) and concluded the combination was safe and “encouraging CBR [clinical benefit rate] was observed,” justifying further study [1]. Independent reviews and news coverage from 2025 record that only a very small number of active clinical investigations existed and that the human program remained limited to early‑phase, exploratory work rather than definitive randomized trials [2] [4].
2. Preclinical enthusiasm drove the trials — but translational gaps are clear
Laboratory studies across multiple cancer types show ivermectin can kill cancer cells or sensitize them to other agents in cell lines and mice — examples include pancreatic and lung cancer models and combinations with agents like recombinant methioninase or paclitaxel [5] [6]. Yet reviews and cancer specialty summaries repeatedly warn that doses effective in mice or cell culture may be toxic or impractical in humans, and that clinical evidence in people was lacking as of 2025 [2] [3] [7].
3. Outcomes reported so far are modest and inconsistent
Conference reporting of the TNBC trial showed a safety signal but limited efficacy data: small numbers were evaluated and signals like one partial response, one stable disease, and multiple progressions were described in press coverage summarizing ASCO presentations — these are preliminary and from early cohorts, not randomized efficacy endpoints [4] [1]. Oncology commentators and news outlets characterized the ASCO abstract as showing “no real benefit” for many patients, underscoring disagreement about interpretation of early results [8] [4].
4. Expert reviews and oncology societies urge caution — misinformation complicates the landscape
Multiple 2025 reviews and commentaries stress that there is no high‑quality clinical evidence supporting ivermectin for cancer and that interest on social media and patient demand risks self‑medication and diversion from proven therapies [2] [3] [9]. An Annals of Oncology analysis explicitly concluded there was no clinical evidence in humans supporting ivermectin’s role in cancer and noted only one active trial at the time of its review [2].
5. Where the evidence could go next — required trials and hurdles
Authors of reviews and later 2025 systematic pieces call for properly powered randomized trials, optimization of formulation/dosing, and combination strategies with immunotherapy or chemotherapy — but they also note practical obstacles: safety at potentially higher anticancer doses, regulatory oversight, and the need to move beyond single‑site, small phase I/II studies to phase III efficacy trials before any change in practice [10] [2].
6. What’s missing from reporting and how to read the signal
Available sources do not report large‑scale randomized controlled trials of ivermectin in any cancer type as of the cited 2025 literature; they also do not show regulatory approval of ivermectin for oncology indications [2] [9]. Media pieces and oncology summaries sometimes differ in tone — some highlight promising preclinical science and early safety, others emphasize the absence of human efficacy data and risks of off‑label self‑use [11] [8]. The balance of expert reviews is cautionary: laboratory promise has not yet translated into human proof [3] [2].
Limitations and final context: the picture above is drawn from conference abstracts, reviews, and early‑phase reports available in 2025; full peer‑reviewed phase II/III results — if completed after these reports — are not found in the provided sources. For patients and clinicians, the prudent stance from oncology authorities in these sources is clear: ivermectin remains investigational in cancer and use should be confined to clinical trials [2] [3] [9].