3.5-Year follow-up of intralesional cidofovir protocol for pediatric recurrent respiratory papillomatosis.

OBJECTIVES: Intralesional injection of cidofovir has been described as an adjunctive treatment for pediatric recurrent respiratory papillomatosis (RRP). However, questions remain regarding the optimal dosing schedule and side-effect profile. The objective of this study was to describe patient outcomes following a standardized cidofovir protocol.

METHODS: Eleven pediatric patients originally treated with a standardized stepped-dose protocol of intralesional cidofovir for RRP were followed for an extended observational period. Additional interventions, disease severity, and adverse outcomes were recorded.

RESULTS: Five of 11 patients have required no further treatments following the original cidofovir protocol. Two patients initially achieved remission but have subsequently required additional treatment for recurrent disease. Four patients never achieved remission and have undergone multiple additional interventions. Mean follow-up time for all patients from the conclusion of the original study was 30.2 months (10-45). No adverse outcomes were noted.

CONCLUSIONS: Intralesional injection of cidofovir may have some potential as an adjunct in the treatment of RRP. Response to cidofovir is unpredictable. Further study of cidofovir is necessary to more clearly define whether the favorable responses observed represent a true treatment effect or simply reflect the natural history of the disease. Perhaps as important is to refine treatment protocols and informed consents that reflect the concern about the carcinogenic potential of cidofovir and to better characterize the drug's side-effect profile.