What clinical trials are currently testing ivermectin in cancer patients and what are their designs?
Executive summary
Two clinical studies are publicly associated with testing ivermectin in oncology, but only one—the Cedars‑Sinai phase I/II trial NCT05318469—has detailed, actively reported design elements: it combines oral ivermectin with an anti‑PD‑1 checkpoint inhibitor for metastatic triple‑negative breast cancer (mTNBC) and is a dose‑finding plus early efficacy study (phase I/II) expected to report by 2026; broader clinical evidence remains very limited and mostly preclinical [1] [2] [3] [4].
1. Which trials are currently registered or reported
The clearest, repeatedly cited study is NCT05318469, a phase I/II investigator‑initiated trial at Cedars‑Sinai evaluating ivermectin combined with balstilimab (an anti‑PD‑1) in metastatic triple‑negative breast cancer, and listed in conference abstracts and trial registries [1] [2] [5]. Some sources mention a second ClinicalTrials.gov record (NCT04447235) that includes ivermectin in a different context, but public details for that record are sparse in the materials reviewed and it is not portrayed as a cancer immunotherapy trial in the reporting examined [6] [5]. Multiple reviews and news articles state that only one active phase I/II oncologic ivermectin trial is enrolling or reported publicly as of 2024–2025 [3] [7].
2. Trial designs: phase, combination strategy and dosing schedules reported
The Cedars‑Sinai study is designed as a combined phase I/II trial to assess safety, tolerability, dose‑finding and early signs of efficacy when oral ivermectin is added to an immune checkpoint inhibitor regimen—balstilimab (and sometimes discussed with pembrolizumab in related materials)—on a 21‑day cycle, with ivermectin given intermittently in the first three days of each week‑three cycle and the PD‑1 antibody given on day 1; treatment may continue for up to 35 cycles (roughly two years) or until progression or toxicity, with post‑treatment follow‑up [8] [5] [2]. Conference reporting and institution summaries frame the study as a safety/dose escalation phase followed by expansion cohorts to look for signals of activity typical of phase I/II oncology designs [1] [2].
3. Patient populations, endpoints and expansion cohorts
The trial targets adults with metastatic triple‑negative breast cancer after prior lines of therapy, including expansion cohorts specifically for PD‑L1–negative TNBC in some reports, which reflects an intent to test whether ivermectin can “turn cold tumors hot” and sensitize PD‑L1 negative tumors to checkpoint blockade [2] [5]. Primary endpoints reported are safety, maximum tolerated dose and recommended phase II dose; secondary and exploratory endpoints include objective responses, progression‑free survival and biomarker assessments such as T‑cell infiltration and PD‑L1 status—typical translational endpoints for combination immunotherapy trials [2] [1].
4. Context, limitations and competing narratives
The clinical effort is small and early: most literature emphasizes that ivermectin’s anticancer rationale is drawn predominantly from in vitro and animal studies demonstrating apoptosis, pathway modulation and tumor reduction, not from large human randomized trials, and cautions against extrapolating lab findings to clinical efficacy [4] [9] [10]. Media and integrative‑medicine outlets sometimes amplify anecdotal case compilations and off‑label use narratives, but peer‑reviewed and registry sources point to only a formal phase I/II program in TNBC as the substantive clinical test to date; some outlets claim two registered U.S. studies but give limited corroborating design detail beyond the Cedars‑Sinai protocol [5] [11] [3].
5. What to watch next and why it matters
The trial’s safety readout, recommended dose and any objective responses in expansion cohorts will determine whether ivermectin progresses to larger randomized testing; even promising phase I/II results would still require phase III RCTs before changing practice, a point stressed across reviews and oncologist commentary [4] [7] [3]. Given the drug’s widespread public visibility and off‑label use, transparent publication of dosing, toxicity and biomarker data from NCT05318469 is essential to separate robust science from anecdote and to guide whether additional trials—across tumor types or as combination strategies—are warranted [1] [10].