What clinical trials have tested repurposed drugs (like itraconazole or remetinostat) for basal cell carcinoma and what were their outcomes?

1. Itraconazole — old antifungal, new target: trial design and biological signal

Itraconazole, an established antifungal, was repurposed because it inhibits the Hedgehog signaling pathway that drives many BCCs; preclinical mouse work showed tumor suppression and this biology motivated a Stanford phase II open‑label trial that enrolled 29 patients with 101 tumors to assess oral itraconazole’s anti‑BCC activity (patients received regimens including 200 mg twice daily for one month or lower doses) ^{[5] [6] [2]}.

2. Itraconazole — outcomes reported and what they mean

The Stanford study reported pathway effects—a mean reduction in HH pathway activity of about 65% in the higher‑dose group—and a median tumor size reduction roughly in the mid‑20% range, leading authors to conclude itraconazole demonstrates anti‑BCC activity in humans and merited larger, longer trials to compare against established HH inhibitors ^{[2] [1]}.

3. Itraconazole — limits and follow‑on work

Interpretation of that signal is constrained: the study was small, open‑label, of short duration, and measured biochemical pathway suppression alongside tumor diameter changes rather than randomized clinical endpoints; the authors explicitly framed the results as exploratory and a rationale for larger trials rather than definitive evidence that itraconazole should replace standard HH inhibitors ^{[1] [6]}. A topical itraconazole trial (NCT02120677) was registered to explore local formulation and Hedgehog (Gli) response as a primary outcome, indicating continued interest but not yet producing large definitive efficacy results in the sources reviewed ^[6].

4. Remetinostat — a topical epigenetic approach: trial setup

Remetinostat is a topical pan‑HDAC inhibitor designed for strong skin activity with rapid systemic metabolism to limit systemic exposure; investigators tested 1% gel applied three times daily for six weeks in a single‑arm, phase II, single‑institution trial that measured tumor diameter at baseline and week eight and performed surgical excision afterward for pathology ^{[7] [8] [9]}.

5. Remetinostat — efficacy and safety outcomes

Published trial results reported a clinically meaningful reduction in BCC disease burden with an overall response rate reported around 69.7%, which included 17 complete responses and 6 partial responses among evaluable lesions; the study concluded remetinostat was well tolerated with no systemic serious adverse events and the most common toxicity being an eczema‑like local skin reaction ^{[4] [3] [10]}.

6. Context, competing options, and remaining questions

Both repurposing efforts must be read against existing HH pathway drugs (for example, vismodegib) and standard surgical management; the itraconazole work signals biological activity but lacks the randomized, comparative data needed to displace approved agents, while remetinostat’s topical route and high local response rate in a single‑arm trial are promising yet require randomized trials assessing durability, longer‑term recurrence rates, and comparative effectiveness versus surgery or systemic therapy ^{[1] [3]}. Sources emphasize the need for larger, longer, and controlled studies to establish where these therapies fit in clinical practice and to quantify risks and benefits beyond early‑phase signals ^{[1] [6] [3]}.

7. Bottom line

Clinical trials of repurposed itraconazole demonstrated Hedgehog pathway inhibition and modest tumor shrinkage in a small phase II cohort (supporting “anti‑BCC activity” but not proving superiority to standard agents), while the topical HDAC inhibitor remetinostat produced a high response rate with primarily local skin toxicity in a phase II single‑arm trial; both lines of research justify further randomized studies to determine long‑term outcomes, comparative efficacy, and optimal clinical roles ^{[2] [1] [3] [4]}.