Abstract 155P
Background
Recurrent respiratory papillomatosis (RRP) is a benign neoplasm of the respiratory system caused by the human papilloma virus. A prospective, multi-center, single-arm, multi-cohort, phase 2 trial was conducted to investigate the efficacy and safety of angiogenesis inhibition with bevacizumab or programmed death 1 blockade with sintilimab in patients with aggressive RRP. Herein, we report results of the pediatric cohort treated with bevacizumab.
Methods
Eligible patients were aged 18 years old or younger and diagnosed with RRP. Patients with an aggressive course had lung involvement or underwent frequent surgeries (≥ 4 times in the previous 12 months). All patients received systemic bevacizumab treatment for up to 6 months (investigator’s choice of 5mg/Kg on day1, 14 days per cycle; or 7.5mg/Kg on day1, 21 days per cycle). The primary endpoint was the change in the number of surgeries per 12 patient-months before and after bevacizumab treatment. Secondary endpoints included objective response rate and adverse events (AEs).
Results
A total of 20 patients were treated. The median age was 5 years old (range 2-10), with 70% of patients being male. Three patients (15%) had undergone tracheotomy, and eight patients (40%) had pulmonary papilloma. The median number of surgeries one year before treatment was 4.5 (range 0-12). Twelve patients (60%) had at least 12 months of follow-up data available. Using each patient's surgical history as their own control, we observed a significant reduction in the number of surgeries required after bevacizumab treatment (p＜0.001). However, papilloma recurrence/progression occurred within a median duration of 4.9 months (range 1.2-10.8) after discontinuation of bevacizumab. Subsequent response was observed in all patients when bevacizumab treatment was resumed. According to RECIST 1.1 criteria, all evaluable lesions showed an objective response. The most common treatment-related AEs of any grade were lip cyanosis (15%) and hand-foot syndrome (10%). No ≥ grade 3 AEs or treatment-related death occurred.
Conclusions
Systemic bevacizumab is a safe and effective alternative to frequent surgical treatment in pediatric patients with aggressive RRP.
Clinical trial identification
ChiCTR2200059627.
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.