24-month follow-up of intralesional cidofovir protocol for pediatric RRP

Abstract

Objectives: Intralesional injection of cidofovir is a potentially useful adjunctive therapy in the treatment of pediatric recurrent respiratory papillomatosis (RRP). However, questions remain regarding the optimal dosing schedule and side-effect profile. The objective of this study was to assess long-term efficacy and safety of cidofovir use. Methods: Eleven pediatric patients originally treated with a standardized stepped-dose protocol of cidofovir therapy for RRP were followed for an additional 24 months following conclusion of the original study. Additional interventions, including further cidofovir injections, were performed as necessary during the extended follow-up period. Effects on disease severity and adverse outcomes were recorded. Results: Of the 7 patients who experienced resolution of their RRP at the end of the stepped-dose protocol, 4 have maintained good results, 2 have relapsed requiring further interventions, while 1 has been lost to follow up. Of the remaining 4 patients with persistent disease following the original cidofovir protocol, 1 has experienced spontaneous regression of disease while the other 3 have required multiple subsequent interventions. In total, 5 of 11 patients have required no further treatments following the original cidofovir protocol. Mean follow-up time for all patients from the conclusion of the original study was 17.7 months (833). No adverse side effects were recorded. Conclusions: Intralesional injection of cidofovir seems to be a safe and effective adjunct in the treatment of RRP. In patients with mild disease, cidofovir might help induce sustained remission, while its continued use may mitigate severity in refractory disease.