Author(s)
Taylor F1, Shields A1, Li S1, Yip C1, Padilla B1, Green T2, Radia D3, Deininger M4, Gotlib JR5, Bose P6, Drummond MW7, Hexner E8, Robinson W9, Quiery, Jr. A10, Winton EF11, DeAngelo DJ12, Mar B2
1Adelphi Values, Boston, MA, USA, 2Blueprint Medicines, Cambridge, MA, USA, 3Guy's and St. Thomas' NHS Foundation Trust, London, UK, 4University of Utah, Huntsman Cancer Institute, Salt Lake City, UT, USA, 5Stanford Cancer Institute, Stanford, CA, USA, 6University of Texas MD Anderson Cancer Cente, Houston, TX, USA, 7Beatson West of Scotland Cancer Centre, Glasgow, UK, 8Abramson Cancer Center at the University of Pennsylvania, Philadelphia, PA, USA, 9University of Colorado Hospital, Aurora, CO, USA, 10Rogel Cancer Center, Ann Arbor, MI, USA, 11Winship Cancer Institute of Emory University, Atlanta, GA, USA, 12Dana Farber Cancer Institute, Boston, MA, USA
OBJECTIVES: To psychometrically evaluate the Advanced Systemic Mastocytosis Symptom Assessment Form (AdvSM-SAF) scores among patients with advanced systemic mastocytosis (AdvSM). METHODS: Designed to assess AdvSM symptoms, the tool was administered as a daily diary (scored as a 7-day average) in BLU-285-2101, a Phase I trial designed to evaluate the effect of the KIT inhibitor avapritinib in subjects with AdvSM. The AdvSM-SAF has 10 items that create a Total Symptom Score (TSS), Gastrointestinal Symptom Score (GSS), and Skin Symptom Score (SSS). Psychometric evaluation of the AdvSM-SAF is supported by other assessments in BLU-285-2101: European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30), Patient Global Impression of Severity (PGIS), and Eastern Cooperative Oncology Group Performance Status (ECOG-PS). RESULTS: Thirty-one patients with this rare malignancy contributed to the analyses (51.6% female; mean age=63.7 [±10.3]). At Baseline, internal consistency reliability (α) for the weekly TSS, GSS, and SSS was 0.844, 0.801, and 0.789, respectively. Test-retest reliability among patients who exhibited no change in ECOG-PS between Baseline and Day 8 was assessed using the intra-class correlation coefficient (ICC); ICCs (95% confidence intervals) for the weekly TSS, GSS, and SSS were 0.945 (0.863, 0.978), 0.883 (0.716, 0.952), and 0.955 (0.888, 0.982), respectively. Construct validity and known-groups analysis showed AdvSM‑SAF scores more strongly (r≥0.60) correlated to EORTC QLQ-C30 symptom items than to more distal concepts at multiple timepoints and were able to distinguish among clinically unique groups specified by PGIS at Baseline (p<0.05; exclusive of weekly DDS [p=0.688]). Observed correlations of AdvSM-SAF and other assessment change scores over time reflect evidence of score sensitivity. CONCLUSIONS: The AdvSM-SAF produced reliable, construct-valid, and sensitive scores when administered in the target patient population. These results, along with its strong development history and evidence of content validity, support its use in clinical studies designed to evaluate AdvSM treatments.
Conference/Value in Health Info
2019-11, ISPOR Europe 2019, Copenhagen, Denmark
Code
PRO143
Topic
Patient-Centered Research
Topic Subcategory
Patient-reported Outcomes & Quality of Life Outcomes
Disease
Oncology, Rare and Orphan Diseases
