Clinical update on 10 children treated with intralesional cidofovir injections for severe recurrent respiratory papillomatosis

Objectives: To continue assessment of the benefits and risks of intralesion al administration of cidofovir, an acyclic nucleoside phosphonate, for trea ting severe recurrent respiratory papillomatosis (RRP) in pediatric patient s,and to discuss guidelines for larger prospective multi-institutional stud ies of the use of cidofovir. Design: Prospective case series. getting: Tertiary care children's hospital . Patients: A total of 10 patients with severe RRP (defined as requiring debu lking procedures to maintain airway patency at least once a month) underwen t intralesional cidofovir therapy. The original 5 patients have received mo re than 1 year of follow-up since their last cidofovir injection, and 5 sub sequent patients have been treated with a revised injection protocol. Intervention: Microsuspension laryngoscopy with intralesional injection of cidofovir after repetitive carbon dioxide laser treatments and mechanical d ebulking of papillomas. Main Outcome Measures: Papilloma stage at the time of serial laryngoscopies . Histologic examination of biopsy specimens of laryngeal tissue obtained 1 year or more after last cidofovir injection. Results: There was evidence of marked improvement in the 4 of the 5 new pat ients enrolled under the revised injection protocol, continuation of a dise ase-free state in 1 of the original 5 patients, and sustained improvement i n 4 of the 5 original patients, resulting in a significantly reduced interv al of intervention. Conclusions: Intralesional cidofovir therapy continues to show benefit in t he treatment of severe RRP in pediatric patients. Safety profiles have not been fully established, but current histologic data are reassuring.