Ivermectin & Fenbendazole for Lung Cancer: 63 Cases Analyzed (2026)

Medically reviewed by Dr. Frank Yap, MD | Written by OneDayMD Editorial Team | First published October 1, 2026 | Updated October 17, 2026 (v3.0)

Source disclosure. 48 of the 63 entries (76%) come from posts by one individual, William Makis, with an ivermectin cancer clinic in Florida. Five entries (50–54) come from Leading Edge Clinic (Dr. Pierre Kory). The rest are anonymous patient or family testimonials. None was independently verified.

Quick Answer

The primary case series lists 63 entries. After removing 7 non-analyzable entries and 4 duplicate patients, 52 unique lung-primary patients remain.

• Small cell lung cancer (SCLC): 8 patients (15.4%), Cases 1, 4, 23, 28, 30, 41, 46, 57.
• Biomarker-defined: 13 patients (25.0%). Four state a driver (EGFR ×3, ALK ×1); nine more imply one through a named targeted drug. None reports PD-L1, TMB or a sequencing panel.
• Immunotherapy: 9 patients (17.3%), plus 1 head-and-neck primary with lung metastases.
• Concurrent standard therapy disclosed: 29 of 52 (55.8%). Only 3 state that they had none.

These cases are hypothesis-generating and do not establish that fenbendazole, ivermectin, or mebendazole directly caused the reported tumor responses. Establishing causality requires well-designed clinical studies that account for other treatments, disease characteristics, and potential confounding factors.

Contents

1. Abstract
2. Methods and counting rules
3. Results: SCLC, biomarkers, immunotherapy
4. Case-level matrix (63 entries)
5. Corrections to the previous version
6. Interpretation and limitations
7. FAQ
8. Using this page with AI assistants
9. Sources and disclosures

1. Abstract

• Background: Fenbendazole, ivermectin and mebendazole are antiparasitic drugs with preclinical anticancer activity in lung cancer. 
• Objective: To classify a public archive of 63 lung cancer narratives by histology, biomarker status, immunotherapy exposure and concurrent standard treatment. 
• Methods: Each entry in the primary case series (September 2026 update) was re-read and coded from its source text; duplicates were merged. 
• Results: 52 unique patients were analyzable: 8 SCLC, 25 NSCLC, 3 other neuroendocrine, 1 rare biphasic tumor and 15 without stated histology. Thirteen had an explicit or implied driver alteration, 9 received immunotherapy, and 29 disclosed concurrent chemotherapy, radiotherapy, immunotherapy or targeted therapy. 
• Conclusion: The archive is E0–E2 evidence (about CEBM Level 4–5). Attribution to the antiparasitic drugs is not possible; prospective, biomarker-annotated trials are needed.

Introduction

Lung cancer remains one of the most challenging and deadly malignancies worldwide, with limited effective treatment options for advanced stages despite advances in targeted therapies and immunotherapies. Patients with metastatic or treatment-resistant disease often face poor prognoses and unmet clinical needs, prompting exploration of novel and adjunctive therapeutic approaches.

For patients with actionable mutations identified through molecular profiling, targeted therapies are the preferred treatment approach. In particular, for "PD-L1 High Non-Small Cell Lung Cancer", single-agent immunotherapy may be more effective and better tolerated than chemotherapy in selected patients.

The preference for targeted treatments reflects their demonstrated efficacy in improving outcomes in these molecularly defined subgroups, underscoring the importance of comprehensive genomic profiling in guiding personalized therapy decisions. However, targeted agents are only applicable to small patient subsets.

Repurposing existing drugs with known safety profiles represents a promising strategy to expand the therapeutic arsenal against lung cancer. Fenbendazole, ivermectin, and mebendazole—widely used antiparasitic agents—have recently garnered attention for their potential anticancer properties demonstrated in preclinical studies and emerging clinical observations. These drugs exhibit multiple mechanisms of action, including inhibition of cancer cell proliferation, induction of apoptosis, disruption of microtubule dynamics, and enhancement of anticancer immune responses.

The potential applications of Ivermectin and Fenbendazole in cancer treatment have sparked significant interest online, with growing communities exploring these compounds for therapeutic use. While both have roots in anti-parasitic medicine, emerging research and anecdotal evidence suggest they may offer benefits in combating lung cancers.

In 2025 (Malak et al) - 2025 Paper from Middle East identifies how Ivermectin kills Lung Cancer cells. Authors concluded that in this mouse model (which keeps the immune system intact, unlike some other models), Ivermectin acted as a powerful anti-cancer agent. Ivermectin shrank tumors, reduced inflammation, slowed growth, triggered cancer cell death, and shut down a critical survival/growth pathway (EGFR/PI3K/AKT/mTOR/VEGF), while also promoting apoptosis. The authors concluded that Ivermectin shows promise as a repurposed drug for NSCLC Lung Cancer and call for more studies, including human clinical trials.

In 2020 (Juarez et al) - Antitumor effects of ivermectin at clinically feasible concentrations support its clinical development as a repositioned cancer drug. Ivermectin was tested at 2mg/kg/day which translates to roughly 5uM in vitro concentration. Lung cancer cell line was ranked no. 4 as one of the most sensitive cancer cell lines.

This review aims to classify a public archive of 63 lung cancer narratives by histology, biomarker status, immunotherapy exposure and concurrent standard treatment. Each entry in the primary case series (September 2026 update) was re-read and coded from its source text; duplicates were merged. By re-examining these real-world therapeutic successes and the underlying scientific rationale, we aim to provide an evidence-informed overview of how these repurposed agents may contribute to potential improved outcomes for patients with metastatic, advanced or treatment-resistant lung cancer.

2. Methods and counting rules

• Histology is taken as written; “lung cancer” without a type is “unspecified”.
• Explicit biomarker (E): the mutation is named. Inferred (I): a biomarker-matched drug is named (osimertinib → EGFR, sotorasib → KRAS G12C, selpercatinib → RET). Inferred calls are not confirmed results.
• Immunotherapy: a checkpoint inhibitor, or “immunotherapy”, is stated in the source.
• Duplicates: same age, sex, location, doses and scan figures or quotes in two posts.
• Counts reflect what the posts say, not verified records. The image-only Cases 11 and 12 could not be read.

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Step	Entries	Detail
Entries on primary page	63	Cases 1–63 (50–54 are five Leading Edge Clinic patients)
Excluded	−7	11, 12 (image-only); 3 (no drug or outcome in text); 19 (ivermectin + chlorine dioxide, hearsay); 20 (head-and-neck primary); 42, 56 (mesothelioma)
Analyzable lung-primary entries	56
Duplicate patients merged	−4	9 = 14; 26 = 33; 32 = 45; 40 = 61
Unique analyzable patients	52	Denominator for all percentages

3. Results

3.1 Histology (n = 52)

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Group	n	%	Cases
SCLC	8	15.4	1, 4, 23, 28, 30, 41, 46, 57
NSCLC (adenocarcinoma 5, squamous 1, NOS 19)	25	48.1	5, 6, 10, 14, 15, 16, 21, 22, 25, 26, 31, 32, 34–36, 40, 44, 47, 48, 50–53, 59, 63
Other neuroendocrine (not SCLC)	3	5.8	27 (NSCLC + LCNEC), 29, 43 (LCNEC)
Biphasic tumor	1	1.9	54
Histology unspecified	15	28.8	2, 7, 8, 13, 17, 18, 24, 37, 38, 39, 49, 55, 58, 60, 62

3.2 Small cell lung cancer (8 patients)

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Case	Stage / sites	Conventional therapy in source	Reported outcome	Note
1	IV (Joe Tippens, 2017)	Not stated on page	“Complete scan response”	Independent fact-checks report concurrent enrolment in a pembrolizumab trial. The source page also calls his cancer NSCLC elsewhere.
4	IV; vertebrae, brain	Chemotherapy (failed), nivolumab	Brain disease resolved	Immunotherapy
23	III, 8 cm	Not stated	Near-complete regression, 2 mo	Standard care for limited-stage disease is chemoradiation; unreported use cannot be excluded
28	IV; brain, liver	Chemotherapy ×2; hyperbaric oxygen	Lung mass no longer visible	SCLC responds quickly to chemotherapy
30	IV; multiple brain	Not stated	Brain lesions −33 to −86% (volume)	Brain radiotherapy not mentioned
41	IV; brain, nodes	Chemotherapy, radiotherapy, immunotherapy	Lung 10.8 → 2.0 cm; brain resolved	Immunotherapy; albendazole + fenbendazole
46	IV; bone	Chemotherapy	“Almost cancer free”	No imaging data
57	IV; pleura	Selpercatinib (RET inhibitor)	“Cancer free”, 8 mo	RET alterations are very unusual in SCLC; histology should be verified

Summary: 5 of 8 document conventional therapy on the page (chemotherapy ×4, selpercatinib ×1); 3 involve immunotherapy (Cases 1, 4, 41); only Cases 23 and 30 are silent. Case 43 (LCNEC) is neuroendocrine but not SCLC.

3.3 Biomarker-defined cases (13 patients, 25.0%)

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Biomarker	Basis	Patients (cases)	Matched drug
EGFR (explicit)	E	3 (35, 51, 52)	Osimertinib in 52; chemotherapy only in 35; none in 51
ALK (explicit)	E	1 (50)	Alectinib
EGFR (inferred)	I	6 (10, 14=9, 32=45, 36, 60, 61=40)	Osimertinib
KRAS G12C (inferred)	I	1 (44)	Sotorasib + chemotherapy
RET (inferred)	I	1 (57, SCLC)	Selpercatinib
Driver unknown	I	1 (8)	“Targeted gene therapy drug”, unnamed

• Totals: EGFR 9 patients (17.3%); 7 of them on osimertinib. Eleven of the 13 received a matched targeted drug, so their responses are expected from that drug.
• Possible but unconfirmed: Case 63 names amivantamab (an EGFR–MET antibody) in its commentary without stating mutation or treatment.
• Case 6 says mutation testing was done and was “not favorable” but gives no result. Case 43 reports Ki-67 90%; Cases 40/61 track CEA. Neither is a driver biomarker.
• Not reported anywhere: PD-L1, tumor mutational burden, next-generation sequencing panels, TP53/RB1 (SCLC), STK11/KEAP1. Thirty-nine patients (75%) have no driver information at all; Case 31 is a never-smoker with no biomarker or targeted drug disclosed.

3.4 Immunotherapy (9 lung-primary patients, 17.3%)

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Agent	n	Cases	Histology
Pembrolizumab (Keytruda)	4	5 (+ chemotherapy), 16 (since Apr 2024), 47, 55 (+ proton RT)	NSCLC 3, unspecified 1
Nivolumab (Opdivo)	1	4 (+ failed chemotherapy)	SCLC
“Immunotherapy”, agent unnamed	4	6 (+ chemotherapy), 34, 41 (+ chemoradiation), 49	NSCLC 2, SCLC 1, unspecified 1
Not counted	2	20 (head-and-neck primary, pembrolizumab); 1 (Tippens, external reports)

None of the nine reports PD-L1. Checkpoint inhibitors can cause delayed or durable responses, so regression after adding an antiparasitic drug (Case 16 had been on pembrolizumab nine months) cannot be assigned to it. Overall, 20 of 52 patients (38.5%) were on immunotherapy or a matched targeted drug; a further 9 had chemotherapy or radiotherapy only.

3.5 Duplicate patients

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Pair	What changed between posts
40 and 61	The later post adds osimertinib to chemotherapy; same CEA 719 and doses
32 and 45	Same 6.4 × 5.3 cm mass; osimertinib in both, tumor 3.5 vs 2.9 cm at 3 vs 8 months
26 and 33	The later post adds carboplatin/paclitaxel + radiation; identical radiologist quote
9 and 14	The later post adds osimertinib; same 6 → 3.6 cm adrenal lesion

In three of four pairs the earlier post omitted standard treatment that a later post disclosed, so “none stated” should be read as “unknown”.

4. Case-level matrix (63 entries)

Key: E/I = explicit/inferred biomarker; osi = osimertinib; IO = immunotherapy; EXC = excluded; NOS = not otherwise specified; mo = months. “Calc” = percentage computed by a chatbot from reported dimensions. Evidence tier: all E0–E1 except Cases 50–54 (E2). Attribution: A0–A1.

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#	Diagnosis / stage	Biomarker	Conventional therapy	Outcome as reported	Flag
63	NSCLC IV; brain, adrenal	EGFR/MET? unconfirmed	Not stated	Brain mets “cleared”, 8 mo	New
62	Lung mass 6 cm, NOS	—	Not stated	“Complete resolution”, 6 mo
61	NSCLC IV; brain, bone	EGFR (I)	Chemo + osi	CEA 719 → 9.1	= 40
60	Recurrent lung ca, NOS	EGFR (I)	Osi	“NED”, 5 mo
59	NSCLC IV	—	Chemo	Tumor smaller, 3 mo
58	Lung ca IV; bone, brain	—	Not stated	Survived “almost three years” (past tense)
57	SCLC IV; pleura	RET (I)	Selpercatinib	“Cancer free”, 8 mo	SCLC
56	Pleural mesothelioma + salivary ca	—	Not stated	PET “no cancer”	EXC
55	Lung ca, NOS (85F)	—	Pembrolizumab + proton RT	“Cancer free”, 6 mo	IO
54	Biphasic tumor, recurrent	—	Carbo/etoposide + RT	Irradiated nodules shrank; others grew
53	Squamous IV; liver	—	Liver RT; prior SBRT	Stable, 7 mo
52	Adenocarcinoma IV	EGFR (E)	Osi	Tumor and nodes smaller, 16 mo
51	Adenocarcinoma IIIC	EGFR (E)	None (stated)	Stable, 6 mo
50	Adenocarcinoma IV	ALK (E)	Alectinib	Complete remission
49	Lung ca IV; bone, NOS	—	IO (agent unnamed)	Bone lesions smaller, 4 mo	IO
48	NSCLC IV	—	Not stated; later keyhole surgery	“Cancer free”, 12 mo
47	NSCLC IV; liver	—	Pembrolizumab	Liver mets smaller or resolved	IO
46	SCLC IV; bone	—	Chemo	“Almost cancer free”	SCLC
45	NSCLC IV; soft tissue	EGFR (I)	Osi	−93% volume (calc)	= 32
44	NSCLC IV; bone	KRAS G12C (I)	Chemo + sotorasib	>50% regression after drug added
43	LCNEC, Ki-67 90%	Ki-67 only	Not stated	“Cancer free”, 5 mo	Not SCLC
42	Pleural mesothelioma IV	—	Chemo	Nodules smaller	EXC
41	SCLC IV; brain, nodes	—	Chemo + RT + IO	Lung 10.8 → 2.0 cm	SCLC, IO
40	NSCLC IV; brain, bone	CEA only	Chemo	CEA 719 → 18	= 61
39	“Early-stage” lung ca	—	None (stated)	−30% volume (calc)
38	Multifocal lung ca	—	Not stated	−83% volume (calc)
37	Lung ca IV; brain (dx 2019)	—	None since start; prior therapy unknown	Brain and chest stable or smaller
36	NSCLC IV; bone	EGFR (I)	Osi	Regression; bone healing
35	NSCLC IV	EGFR (E)	Chemo	SUV 11.2 → 3.0; effusion resolved
34	NSCLC IV	—	IO (agent unnamed)	Shrinkage, 12 mo	IO
33	NSCLC III, bulky	—	Carbo/paclitaxel + RT	SUV 12.1 → 1.4	= 26
32	NSCLC IV	EGFR (I)	Osi + RT	−84% volume	= 45
31	NSCLC IV; brain, bone, nodes	—	Not stated	Lung and brain clear; bone residual
30	SCLC IV; brain (India)	—	Not stated	Brain lesions −33 to −86% volume	SCLC
29	Multifocal neuroendocrine	—	Not stated	2.2 → 0.8 cm	Not SCLC
28	SCLC IV; brain, liver	—	Chemo ×2	Lung mass not visible	SCLC
27	NSCLC + LCNEC	—	Not stated	~2 cm smaller, 3 mo
26	NSCLC III	—	Not stated here	−89% volume	= 33
25	NSCLC IV; bone	—	Not stated	FDG falls; active nodule remains
24	Lung ca, new	—	Not stated	4.5 → 1.7 cm
23	SCLC III, 8 cm	—	Not stated	Near-complete regression, 2 mo	SCLC
22	NSCLC IV	—	Chemo	−76% volume (calc)
21	NSCLC IV; brain, adrenal	—	Not stated	“Resolving”, 5 mo
20	Head-and-neck primary; lung mets	—	Pembrolizumab + RT	Stable / no recurrence	EXC, IO
19	Lung ca (hearsay)	—	Surgery	“No cancer found”	EXC
18	Lung ca IV (video)	—	Not stated	Regression claimed
17	Lung ca IV; multi-site	—	Chemo	All lesions smaller
16	NSCLC IV; nodes, adrenal	—	Pembrolizumab (since 2024)	Near-complete nodal resolution	IO
15	NSCLC IV; 20+ brain	—	Not stated	Brain lesions smaller, 2 mo
14	NSCLC IV; nodes, liver, adrenal	EGFR (I)	Osi	~75% burden reduction	= 9
13	Lung ca IV; brain, liver, bone	—	Not stated	Liver and bone metabolic resolution	Overlap with 17?
12	Image only	?	?	?	EXC
11	Image only	?	?	?	EXC
10	NSCLC IV	EGFR (I)	Osi	3 → 2 cm; effusion resolved
9	NSCLC IV	—	Not stated	Adrenal 6 → 3.6 cm	= 14
8	Lung ca IV	Unknown (I)	Unnamed targeted drug	6.4 → 2.6 cm
7	Lung ca IV; liver	—	Not stated	Liver mets smaller
6	Adenocarcinoma II → IV	Tested, no result	Chemo ×2 + IO; ADT for prostate ca	Pleural disease resolved	IO
5	Adenocarcinoma IV	—	Chemo + pembrolizumab	Nodules resolved	IO
4	SCLC IV	—	Chemo + nivolumab	Brain disease resolved	SCLC, IO
3	Lung ca IV	—	Chemo + RT	Source text ends; no outcome	EXC
2	Lung ca, metastatic	—	Not stated	5 nodules → 2
1	SCLC IV (Tippens)	—	Not stated on page	“Complete scan response”	SCLC

5. Corrections to the previous version

• Counts: the title said 63 cases, the body said 62, and the matrix omitted Case 63 (September 2026). All 63 are now listed.
• Table layout: rows 50 and 5–1 had shifted columns; rebuilt.
• Case 40: chemotherapy was disclosed in the source (previously “not clearly specified”); it is the same patient as Case 61.
• Case 19: the regimen was ivermectin plus ingested chlorine dioxide, relayed second-hand, not an antiparasitic-only protocol. It is excluded; the FDA has warned against ingesting chlorine dioxide products.
• Case 57: “targeted therapy” is selpercatinib (RET), unusual in SCLC. Case 58: the past-tense survival wording implies the patient has died. Case 3: the source text contains no drug or outcome.
• Cases 11–12: the source is a January 2025 anonymous Substack compilation of subscriber comments by a seller of ivermectin and fenbendazole products; the images could not be read or confirmed as lung cancer.
• Percentages: volume figures computed by a chatbot overstate change relative to diameter. In Case 29, 2.2 → 0.8 cm is a 64% diameter reduction, reported as 95% volume.
• Language: removed statements that mechanisms “align well with observed tumor responses”, that cases suggest chemo- or radiosensitizing effects, and the “tip of the iceberg” conclusion. The Juárez et al. 2020 premise that a 2 mg/kg/day dose approximates the 5 µM used in vitro is now flagged as contested; ASCO cautions that concentrations needed to reproduce laboratory effects may exceed safe human doses.

6. Interpretation and limitations

The dominant pattern is multimodal treatment. Among the 29 patients with disclosed therapy, 9 received immunotherapy, 11 a matched targeted drug (osimertinib, alectinib, sotorasib, selpercatinib) and 9 chemotherapy or radiotherapy only. These treatments produce objective responses on their own, so regression in these patients cannot be credited to the antiparasitic agents. Of the 23 patients with no therapy stated, only three (Cases 37, 39, 51) explicitly report none, and each lacks a verified baseline, chronology or independent imaging review. Case 37 was diagnosed in 2019 and her earlier treatment is not described.

Limitations: self-selected successes, one source for 76% of entries, no denominators for non-responders, unverified imaging, chatbot-calculated volumes, inconsistent follow-up (weeks to years), and unreported toxicity. Recording biomarkers, PD-L1 and treatment dates at entry would make any future registry interpretable.

What would settle the question

A planned University of Florida trial of ivermectin in cancer (ICONIC, NCT07487805) was listed as not yet recruiting at last review. The only larger observational dataset, Hulscher et al. (197 enrolled), carries a June 2026 Anticancer Research Expression of Concern and a disclosed Wellness Company conflict of interest. Related reading: Lung cancer in 2026: precision oncology, biomarker map, case registry.

7. FAQ

How many SCLC cases are in the archive?

Eight of 52 unique patients (15.4%): Cases 1, 4, 23, 28, 30, 41, 46 and 57. Five document chemotherapy, immunotherapy or a targeted drug on the page.

How many cases report biomarkers such as EGFR?

Four state a driver (EGFR ×3, ALK ×1) and nine more imply one through a named targeted drug: 13 of 52 (25.0%). No case reports PD-L1.

How many cases were on immunotherapy?

Nine lung-primary patients (17.3%): pembrolizumab ×4, nivolumab ×1, unnamed immunotherapy ×4.

Do these cases show the drugs work against lung cancer?

No. More than half disclose concurrent standard therapy, and none has verified imaging or follow-up.

What does ASCO recommend?

ASCO’s May 2026 notice advises against ivermectin and fenbendazole for cancer outside clinical trials.

8. Using this page with AI assistants

• Claude: “Using the matrix, list the SCLC cases that had no chemotherapy or immunotherapy stated.”
• ChatGPT: “Summarize the biomarker table and explain why osimertinib confounds Cases 10, 14, 32, 36 and 60.”
• Gemini: “Compare these counts with typical real-world SCLC and EGFR proportions in lung cancer.”
• Perplexity: “Find current trials of ivermectin or mebendazole in lung cancer and their status.”

9. Sources and disclosures

1. Primary case series: OneDayMD, September 2026 update.
2. Leading Edge Clinic cases: Kory blog.
3. Malak et al. 2025 (mouse NSCLC model, preclinical): PubMed 40174264. Juárez et al. 2020: summary.
4. ASCO clinical notice, May 2026: coverage.
5. Tippens trial context: PolitiFact.

Navigation: Ivermectin, Fenbendazole and Mebendazole for Cancer (All Cancer Types) > Review for Lung Cancer > Primary Lung Cancer Case Series.

Evidence scale. E0 testimonial; E1 structured narrative; E2 formal case report; E3 prospective observational; E4 comparative; E5 randomized. E0–E2 corresponds to CEBM Level 4–5.
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Disclaimer: Educational content only, not medical advice. Ivermectin, fenbendazole and mebendazole are not approved for cancer. Discuss any treatment decision with your oncologist.