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 intralesional administration of cidofovir, an acyclic nucleoside phosphonate, for treating severe recurrent respiratory papillomatosis (RRP) in pediatric patients, and to discuss guidelines for larger prospective multi-institutional studies of the use of cidofovir. DESIGN Prospective case series. SETTING Tertiary care children's hospital. PATIENTS A total of 10 patients with severe RRP (defined as requiring debulking procedures to maintain airway patency at least once a month) underwent intralesional cidofovir therapy. The original 5 patients have received more than 1 year of follow-up since their last cidofovir injection, and 5 subsequent 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 debulking 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 patients enrolled under the revised injection protocol, continuation of a disease-free state in 1 of the original 5 patients, and sustained improvement in 4 of the 5 original patients, resulting in a significantly reduced interval of intervention. CONCLUSIONS Intralesional cidofovir therapy continues to show benefit in the treatment of severe RRP in pediatric patients. Safety profiles have not been fully established, but current histologic data are reassuring.