A Mixed Methods Study of Medication Adherence in Adults with Neurofibromatosis Type 1 (NF1) on a Clinical Trial of Selumetinib

Background: Oral therapeutic options for plexiform neurofibromas (PNs) in individuals with neurofibromatosis type 1 (NF1) are receiving attention in clinical research. The MEK inhibitor (MEKi) Selumetinib is FDA-approved in children ages 2+ years with inoperable PNs, and shows activity in adults. Prolonged therapy with selumetinib is necessary to maintain tumor reduction. Therefore, investigating long-term adherence is vital to understand patterns of adherence over time and its impact on clinical outcomes. Mixed methods research offers rich information about adherence that can inform future intervention trials, and can assist practitioners in addressing medication adherence concerns. Methods: This mixed-method pilot study is the first examination of the feasibility of a technology-based adherence assessment method, the medication events monitoring system (MEMSTM), among individuals with NF1-PN. Adherence was monitored in a small sample of patients (N = 12; mean age = 34.36 years; 58% male) with NF1 and PN across eighteen 28-day treatment cycles. Qualitative data were obtained from individual interviews using inductive and deductive techniques for thematic analysis. Results: The predetermined criterion was met, suggesting that using MEMSTM is feasible despite some challenges with the caps. Depression and overall stress were significantly related to reduced adherence, although these results should be considered hypothesis-generating. Barriers to medication adherence included forgetting and the timing of doses related to eating. Facilitators included consistency, reminders, and social support. Conclusions: This study highlights patient characteristics that may be related to increased risk for nonadherence, as well as challenges with electronic pill caps that should be considered in future clinical trials for NF1-related PN. Results can inform future adherence interventions for adults with NF1 and PNs. Future research with larger samples is needed to fully explore factors related to long-term medication adherence among individuals with NF1.