Medically Reviewed By: Dr. Imran Khan, MD, IFMCP
Last Updated: September 12, 2026
Understanding ASCO Abstract e13146 and Trial NCT05318469
ASCO abstract e13146 reports preliminary findings from a Phase I/II study evaluating ivermectin with immune checkpoint therapy in patients with metastatic triple-negative breast cancer (mTNBC). The findings reported at the 2025 ASCO Annual Meeting specifically involved ivermectin with balstilimab, an anti-PD-1 antibody.
As of September 2026, trial NCT05318469 remains a recruiting Phase I/II trial, with the current protocol evaluating ivermectin in combination with balstilimab or pembrolizumab. The preliminary results reported in 2025 specifically involved ivermectin in combination with balstilimab.
Medical Disclaimer: This article is for educational purposes only and is not medical advice or a treatment protocol. Ivermectin is not FDA-approved for cancer treatment, and fenbendazole is not FDA-approved for human use. Neither should replace treatment recommended by your oncology team.
What Results Did ASCO Abstract e13146 Report?
At the time of the 2025 report, 9 patients had enrolled and 8 were evaluable for tumor response. Among those eight patients, researchers reported:
- 1 partial response
- 1 case of stable disease
- 6 cases of progressive disease
The study reported a four-month clinical benefit rate of 37.5% (95% CI, 15.3%–91.7%) among the eight evaluable patients. The wide confidence interval reflects the uncertainty of this early finding. Overall survival was still too early to assess at the time of the 2025 report.
Treatment-related adverse events included rash, anemia, diarrhea, altered taste, muscle weakness, hypothyroidism, and vomiting. The investigators reported that the combination was sufficiently tolerated to support continued investigation.
What Do the Early Results Mean?
The ivermectin and balstilimab results reported in ASCO abstract e13146 provide early human data, but they do not establish ivermectin as an effective cancer treatment.
The study population was very small, the findings were preliminary, and ivermectin was given in combination with balstilimab. As a result, the study cannot determine whether ivermectin itself contributed to the observed clinical response. Larger studies are needed to evaluate effectiveness.
Why Was Ivermectin Combined With Balstilimab?
Preclinical research cited in ASCO abstract e13146 reported increased T-cell infiltration in a mouse model of triple-negative breast cancer. This provided the scientific rationale for studying ivermectin alongside an immune checkpoint therapy.
Balstilimab is an anti-PD-1 antibody. Trial NCT05318469 is investigating whether combining these approaches warrants further study in metastatic triple-negative breast cancer, not whether ivermectin can replace established cancer treatments.
Where Does Fenbendazole Fit Into Current Research?
Fenbendazole is a separate antiparasitic drug being studied for potential anticancer activity. Most available evidence remains preclinical, and a 2024 review published in Anticancer Research identified important gaps in human pharmacokinetics, safety, dosing, and clinical evidence.
Fenbendazole was not part of the study reported in ASCO abstract e13146. Readers interested in the separate evidence can learn more in our Fenbendazole for Cancer research overview.
What Patients Should Know About Early-Phase Cancer Research
Early-phase research can provide important information, but the findings need to be interpreted within the study design. For the findings reported in ASCO abstract e13146, key limitations include:
- Phase I research primarily evaluates safety and dosing.
- Small studies cannot establish treatment effectiveness.
- Conference abstracts provide preliminary rather than definitive evidence.
- A response to a drug combination cannot automatically be attributed to one drug.
- Experimental treatments should not replace established oncology care.
These distinctions are especially important when preliminary findings are discussed without the full context of the study.
How Personalized Cancer Testing May Support Care Discussions
Cancer testing can provide information about tumor characteristics, biomarkers, and circulating tumor cells that may contribute to individualized care discussions. Results should be interpreted alongside a patient's diagnosis, treatment history, and established oncology plan.
IHAWMD offers RGCC Testing, Circulating Tumor Cell Testing, and a Repurposed Drug Assay as part of its personalized approach to cancer care. These tests should not be interpreted as proof that ivermectin or fenbendazole will effectively treat an individual patient's cancer.
Medical Disclaimer: This article is for educational purposes only and is not medical advice or a treatment protocol. Ivermectin is not FDA-approved for cancer treatment, and fenbendazole is not FDA-approved for human use. Discuss experimental or complementary approaches with your treating oncology team.
Discuss Emerging Cancer Research With IHAWMD
If you have questions about emerging cancer research or how experimental findings may relate to your broader care, schedule a consultation with IHAWMD.
Our medical team can help you understand current evidence and its limitations alongside your existing oncology care. Learn more about our personalized cancer care services.
About Dr. Imran Khan
Internal medicine physician in practice since 2011, board certified in internal medicine by ABIM from 2013 to 2023, with residency training at Case Western Reserve University / MetroHealth and practice experience at Cleveland Clinic, Baylor St. Luke's Medical Center, and Memorial Hermann Memorial City. Certified by the Institute for Functional Medicine.
At Internal Healing and Wellness MD, Dr. Khan helps patients explore personalized and functional approaches alongside their established medical care.
Frequently Asked Questions
e13146 is the identifier for a 2025 ASCO conference abstract reporting preliminary ivermectin and balstilimab findings. The associated study is registered as trial NCT05318469; its current protocol includes ivermectin with balstilimab or pembrolizumab.
At the time of the 2025 report, nine patients had enrolled. Among eight evaluable patients, one had a partial response, one had stable disease, and six had progressive disease.
No. ASCO abstract e13146 reports preliminary human data from a small early-phase study and does not establish ivermectin as an effective cancer treatment.
No. The study reported in ASCO abstract e13146 evaluated ivermectin in combination with balstilimab. Fenbendazole was not part of the reported study.
Yes. As of September 2026, trial NCT05318469 is ongoing and recruiting participants. The current protocol includes ivermectin with balstilimab or pembrolizumab, while the 2025 preliminary results specifically involved ivermectin with balstilimab.
References
- Yuan Y, Bitar JS, Walker ML, et al. A phase I/II study evaluating the safety and efficacy of ivermectin in combination with balstilimab in patients with metastatic triple negative breast cancer. Journal of Clinical Oncology. 2025;43(16_suppl). doi:10.1200/JCO.2025.43.16_suppl.e13146.
- ClinicalTrials.gov. Ivermectin in Combination With Balstilimab or Pembrolizumab in Patients With Metastatic Triple Negative Breast Cancer. NCT05318469.
- Nguyen J, Nguyen TQ, Han BO, Hoang BX. Oral Fenbendazole for Cancer Therapy in Humans and Animals. Anticancer Research. 2024;44(9):3725–3735. doi:10.21873/anticanres.17197.
