OBJECTIVES: Pexidartinib (Turalio^®) is the only systemic therapy approved by the FDA for the treatment of adult patients with symptomatic tenosynovial giant cell tumor (TGCT) associated with severe morbidity or functional limitations and not amenable to improvement with surgery. The objective of this study was to assess symptom change over time among patients who were newly initiated on pexidartinib for TGCT in a real-world setting.

METHODS: This was a longitudinal observational study based on surveys with TGCT patients who were newly initiated on pexidartinib. Participants completed patient-reported outcome (PRO) assessments electronically at baseline when initiating pexidartinib and were followed within 12 months. Validated instruments used in the assessments included Patient-Reported Outcomes Measurement Information System physical function (PROMIS-PF), one-item Numeric Rating Scale (NRS) for worst joint stiffness and worst pain, and patients’ global impression of change (PGIC) in overall symptom since initiating pexidartinib. Random slope regression models were developed to adjust for the time since first pexidartinib dose to describe changes in patient-reported domain scores from baseline to last follow-up.

RESULTS: Eleven patients completed the baseline survey and at least one follow-up survey, and median follow-up was 242 days. Mean (SD) age at baseline was 42.2 (12.2) years, and 54.5% were female. Random slope regression model with time (year) since first dose of pexidartinib as an independent variable resulted in statistically significant reduction in worst pain NRS (average rate of change [ARoC] = -2.44; p-value = 0.033), while reduction in worst stiffness NRS (ARoC = -1.82; p-value = 0.199) and improvement in PROMIS-PF (ARoC = 6.33; p-value = 0.243) were not statistically significant. The majority of patients (88.9%) reported “very much improved” or “much improved” in overall symptoms since initiating pexidartinib.

CONCLUSIONS: Most patients reported overall symptom improvement since pexidartinib initiation. Larger real-world studies about PROs of newly initiated pexidartinib patients should be evaluated.