RARE-06. CLINICAL BURDEN AMONG PATIENTS WITH NEUROFIBROMATOSIS TYPE 1 (NF1) AND PLEXIFORM NEUROFIBROMA (PN) IN THE UNITED STATES (US)

BACKGROUND: Plexiform neurofibromas (PNs) occur in 30–50% of pediatric patients with neurofibromatosis type 1 (NF1), often resulting in debilitating pain and dysfunction. Real-world evidence describing the clinical disease burden among these patients is limited. This study aimed to characterize this burden among pediatric NF1 PN patients in the United States (US). METHODS: Caregivers of 82 patients ages 2–18 years with NF1 PN in the US who were treatment naïve or new users of selumetinib (defined as ≤1 month of use) were recruited through the Children’s Tumor Foundation to participate in an online cross-sectional survey from December 1, 2020 through January 14, 2021. Participants responded to items measuring patient demographic and clinical characteristics and the burden of debulking surgeries. RESULTS: On average, patients were 11.5 [standard deviation (SD)=4.0] years old and predominantly treatment naïve (97.6%). Most were white/Caucasian (85.4%), and 53.7% were female. Most patients had been diagnosed with NF1 and PN for >5 years (80.5% and 68.3%, respectively). A majority of patients (58.5%) had >20 café-au-lait spots. Most patients (59.8%) had >1 PN, with 11.0% reporting >5 PNs, frequently located on the back (40.2%) and head (32.9%). Common symptoms included pain (64.6%), disfigurement (32.9%), and motor dysfunction (28.0%). Common comorbidities included attention-deficit disorder (56.1%) and headaches (47.6%). Few patients had received complete resections of their tumors (12.2%), and 39.0% reported ≥1 debulking surgery. Among the 32 patients with debulking surgeries, 5 patients (15.6%) reported complications, including acute complications (60.0%) and post-operative symptoms (40.0%). Debulking surgery-related emergency room visits and hospitalizations were common (25.0% and 53.1%, respectively); mean length of stay per hospitalization was 5.9 (SD=6.2) days. CONCLUSION: The clinical disease burden of NF1 PN among this pediatric patient population is substantial. While debulking surgeries are used for symptom management, they were related to considerable clinical sequelae.