A black box warning describes a potential risk of malignancy associated with topical use of pimecrolimus to treat atopic dermatitis due to its similarity to oral calcineurin inhibitors used in solid-organ transplantation and spontaneous reporting of malignancies, including lymphomas and cutaneous malignancies.
Overall, 7457 children were enrolled in the Pediatric Eczema Elective Registry, for a total of 26 792 person-years. Children used a mean (SD) of 793 (1356) g of pimecrolimus when enrolled in the study. As of May 2014, five malignancies had been reported. These include 2 leukemias, 1 osteosarcoma, and 2 lymphomas. No skin cancers were reported. The standardized incidence ratio for all malignancies (primary outcome) based on the age-standardized SEER population was 1.2 (95% CI, 0.5-2.8). As secondary analyses, the standardized incidence ratios (based on 2 cases for each) were 2.9 (95% CI, 0.7-11.7) for lymphoma and 2.0 (95% CI, 0.5-8.2) for leukemia. None of these findings were statistically significant.
Based on more than 25 000 person-years of follow-up, it seems unlikely that topical pimecrolimus as it was used in the Pediatric Eczema Elective Registry cohort to treat atopic dermatitis is associated with an increased risk of malignancy.
Margolis DJ, Abuabara K, Hoffstad OJ, Wan J, Raimondo D, Bilker WB. Association Between Malignancy and Topical Use of Pimecrolimus. JAMA Dermatol. 2015;151(6):594–599. doi:10.1001/jamadermatol.2014.4305