Itraconazole: The Antifungal Drug With Phase II Cancer Data

The Bottom Line

Itraconazole is a common antifungal drug with Phase II clinical trial data showing activity in prostate cancer and non-small cell lung cancer (NSCLC). It inhibits three cancer-relevant pathways simultaneously: Hedgehog signaling, angiogenesis (via VEGFR2), and mTOR. The prostate cancer trial showed PSA stabilization and progression-free survival benefit. The NSCLC trial showed improved overall survival. It crosses the blood-brain barrier and costs $15-30/month generic.

How It Works

Hedgehog pathway inhibition: Blocks Smoothened (SMO), a key component of Hedgehog signaling that drives cancer stem cell maintenance in basal cell carcinoma, medulloblastoma, prostate, and pancreatic cancers
Anti-angiogenic: Inhibits VEGFR2 glycosylation, blocking VEGF signaling and new blood vessel formation. Mechanism distinct from bevacizumab.
mTOR inhibition: Blocks mTORC1 via cholesterol trafficking disruption, adding a metabolic layer to its anticancer activity
Multi-target advantage: Hitting three pathways simultaneously reduces resistance development compared to single-target drugs

Human Clinical Trial Data

Prostate Cancer Phase II (Antonarakis et al., 2013)

29 men with non-metastatic biochemically recurrent prostate cancer
Itraconazole 200mg twice daily
PSA progression-free survival improved; Hedgehog pathway markers reduced

NSCLC Phase II (Rudin et al., 2013)

23 patients with previously treated NSCLC
Itraconazole 200mg twice daily
Improved overall survival and progression-free survival vs. control arm

Safety

FDA-approved antifungal with decades of use. Main concerns: liver toxicity (monitor LFTs), heart failure risk at high doses, and significant drug interactions (CYP3A4 inhibitor). Do not combine with statins, certain chemo drugs, or calcium channel blockers without medical guidance.

Our Assessment

Itraconazole has legitimate Phase II data in two cancer types, a well-characterized multi-target mechanism, and a known safety profile. It's one of the better-evidenced repurposed drugs on our list. The Hedgehog pathway inhibition is particularly relevant for cancers with stem cell-driven resistance. Worth discussing with an oncologist, particularly for prostate cancer or cancers with known Hedgehog pathway activation.

Sources

Clinical Cancer Research 2013: Phase II prostate cancer (Antonarakis et al.)
Oncologist 2013: Phase II NSCLC (Rudin et al.)
ecancer.org: ReDO Project itraconazole review
PMC: "Repurposing itraconazole as an anticancer agent" (comprehensive review)