A new ecamsule-containing SPF 40 sunscreen cream for the prevention of polymorphous light eruption: a double-blind, randomized, controlled study in maximized outdoor conditions.

Polymorphous light eruption (PMLE) is an idiopathic photodermatosis elicited by UV radiation (UVR). The objective of this double-blind, randomized, controlled, intraindividual, bilateral comparison was to determine the efficacy of the UVA filters (ecamsule, avobenzone) present in the new sun protection factor (SPF) 40 sunscreen cream in preventing PMLE in maximized outdoor conditions (ie, exaggerated sun exposure). Safety also was assessed. Each participant was treated with SPF 40 sunscreen cream containing ecamsule 3%, octocrylene 10%, avobenzone 2%, and titanium dioxide 5% (tetrad) on one side of the body and either an ecamsule-deprived (triad-E) or avobenzone-deprived (triad-A) cream on the other side. Participants were subsequently exposed to incremental doses of sunlight for up to 6 days. The primary efficacy assessment was a composite relative success rate with 3 components. Success was defined as either a delayed time to onset of PMLE or a lower global severity of PMLE comparing one side of the body to the other side in the same participant. Safety evaluations included systemic adverse events (AEs). Of the 144 participants enrolled and randomized, 22 did not experience PMLE during the study duration under these maximized sun exposure conditions. A significantly greater number of successes were detected on the tetrad-treated side compared with either triad: 41 of 73 participants (56%) versus 8 of 73 participants (11%; P<.001) in the triad-E treatment group and 26 of 71 participants (36%) versus 11 of 71 participants (16%; P=.02) in the triad-A treatment group. Polymorphous light eruption appeared later with the tetrad than with either triad. The global severity of the PMLE flares was significantly lower with the tetrad than with both triads at end point (P<.001 and P=.02 for tetrad vs triad-E and tetrad vs triad-A, respectively). In this study, the SPF 40 sunscreen cream containing ecamsule 3%, octocrylene 10%, avobenzone 2%, and titanium dioxide 5% prevented PMLE flares significantly better than similar formulations with only one of the UVA filters (triad-E treatment group, P<.001; triad-A treatment group, P=.02). The inclusion of both ecamsule and avobenzone provides clinical benefit to patients with PMLE compared with formulations containing only one UVA filter.