1. Assessing tolerability with the Functional Assessment of Cancer Therapy item GP5: psychometric evidence from LIBRETTO-531, a phase 3 trial of selpercatinib in medullary thyroid cancer
- Author
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Antoine Regnault, Laurine Bunod, Angely Loubert, Marcia S. Brose, Lisa M. Hess, Patricia Maeda, Yan Lin, Rebecca M. Speck, Adrienne M. Gilligan, and Nalin Payakachat
- Subjects
Medullary thyroid cancer ,Patient-reported tolerability ,Psychometric analysis ,FACT item GP5 ,Public aspects of medicine ,RA1-1270 - Abstract
Abstract Background This psychometric analysis generated evidence to support the use of the Functional Assessment of Cancer Therapy item GP5 (GP5) as a measure of tolerability and confirms the appropriateness of categorizing “high side-effect burden” using a rating of 3 or 4 (score ranges 0–4) in patients with advanced/metastatic RET-mutant medullary thyroid cancer (MTC). Methodology Blinded, pooled interim data from the safety population (n=290) enrolled in the phase 3 LIBRETTO-531 trial (NCT04211337) were used. Intraclass correlation coefficients (ICC) were calculated for test-retest reliability using data from cycles 1-2 post-baseline. Construct validity was evaluated by examining the correlations of GP5 ratings with (a) symptomatic adverse events (AEs; measured by the PRO-CTCAE), and (b) functioning scores of EORTC QLQ-C30. The ability to detect change over time was examined by Cochrane-Mantel-Haenszel tests for GP5 ratings and PRO-CTCAE. The relationship of “high side-effect burden” categories with QLQ-C30 functioning scores was examined. Results ICCs for the GP5 ratings after cycle 1 ranged between 0.80 and 0.85, indicating good reliability. Correlations between GP5 and PRO-CTCAE items ranged from 0.18 to 0.62 and ranged from -0.37 to -0.50 for QLQ-C30 functioning scores, consistent with study assumptions. Post-baseline GP5 ratings showed significant associations with PRO-CTCAE scores (p more...
- Published
- 2024
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