A randomized, phase II, double-blinded study of the efficacy of oleogel-S10 (AP101) gel for the treatment of grade 2/3 radiation dermatitis in breast cancer patients.

Abstract

e24199 Background: Radiation therapy is a cornerstone of treatment for early-stage breast cancer; however, up to one third of patients develop grade 2–3 acute radiation dermatitis (ARD), which is associated with pain, pruritus, and impaired quality of life. Therapeutic options for established grade 2-3 ARD are limited, and not all patients respond adequately to topical corticosteroids. Oleogel-S10 (Filsuvez) is a topical betulin-based gel approved by the U.S. Food and Drug Administration for dystrophic and junctional epidermolysis bullosa that promotes keratinocyte migration and epidermal barrier regeneration. Prior phase III studies have demonstrated accelerated wound healing with Oleogel-S10. We hypothesized that Oleogel-S10 could facilitate healing of high-grade ARD following breast irradiation. Methods: This IRB-approved (Memorial Sloan Kettering Cancer Center IRB #21-091), single-center, phase II, double-blind, randomized controlled trial enrolled women ≥18 years who developed grade 2–3 ARD during conventionally fractionated whole-breast radiation therapy. Patients were randomized 1:1 to Oleogel-S10 or placebo and instructed to apply standard-of-care triamcinolone 0.1% cream daily with study gel nightly for three weeks. The primary endpoint was percent change in ARD body surface area from baseline to day 14, assessed using novel Canfield three-dimensional (3D) imaging. Secondary endpoints included ARD resolution, pigmentation changes, patient-reported outcomes (PRO-CTCAE), and adverse events. Results: Nineteen patients were enrolled, of whom 11 completed the study (six placebo, five Oleogel-S10); attrition rates were similar between groups. No significant difference was observed between groups in percent change in ARD surface area at day 14. Hyperpigmentation at follow-up was lower in the Oleogel-S10 arm, although this difference did not reach statistical significance. Skin pain severity was lower in the Oleogel-S10 group by CTCAE and PRO-CTCAE assessments, but this difference was not statistically significant. Adverse event rates were similar between groups, with no grade 4 or 5 adverse events reported. Conclusions: Although Oleogel-S10 did not improve the primary endpoint of wound surface area as calculated by a novel 3D imaging tool compared with standard-of-care triamcinolone, treatment was associated with a trend toward improvement in skin pain and hyperpigmentation. These findings may represent early signals of therapeutic activity in ARD, particularly for patient-centered outcomes. Interpretation is limited by early study closure related to COVID-19–associated recruitment challenges and small sample size. Larger, adequately powered studies are warranted to further evaluate the role of Oleogel-S10 in the management of grade 2-3 ARD. Clinical trial information: NCT05190770 .