Topical remetinostat gel effective for treatment of basal cell carcinoma, Study finds

The study is published in the Clinical Cancer Research Journal.

James M. Kilgour and colleagues previously conducted a drug repositioning screen using molecular data from human basal cell carcinoma and identified histone deacetylase (HDAC) inhibitors as a potential treatment for basal cell carcinoma and now are able to conduct the first proof-of-principle study of a topical pan-HDAC inhibitor, remetinostat, in human basal cell carcinoma.

The team of researchers conducted a phase II, open-label, single-arm, single-institution trial of a topical HDAC inhibitor. Participants with at least one basal cell carcinoma were recruited.

All participants applied 1% remetinostat gel three times daily for 6 weeks, with measurements of tumor diameter conducted at baseline and week 8.

Surgical excision of the remaining tumor was conducted at the end of the study and microscopic evaluation was performed. Thirty-three per-protocol tumors from 25 participants were included in the analysis.

The results of the study showed that the overall response rate, defined as the proportion of tumors achieving more than 30% decrease in the longest diameter from baseline to week 8, was 69.7% [90% confidence interval (CI), 54%–82.5%].

On pathologic examination, 54.8% of tumors demonstrated complete resolution. Pharmacodynamic analysis demonstrated similar levels of acetylated histone H3 in skin tissue before and after treatment, however, phosphorylation was increased. No systemic adverse events were reported.

As a result, it was concluded that remetinostat is a well-tolerated and effective topical treatment for reducing basal cell carcinoma disease burden in a clinically significant manner. This provides in-human validation of histone deacetylase inhibitors as a therapy for basal cell carcinoma.

DOI: 10.1158/1078-0432.CCR-21-0560