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

Authors

Antoine Regnault
Laurine Bunod
Angely Loubert
Marcia S. Brose, Thomas Jefferson UniversityFollow
Lisa M. Hess
Patricia Maeda
Yan Lin
Rebecca M. Speck
Adrienne M. Gilligan
Nalin Payakachat

Document Type

Article

Publication Date

12-19-2024

Comments

This article is the author's final published version in Journal of Patient-Reported Outcomes, Volume 8, Issue 1, December 2024, Article number 149.

The published version is available at https://doi.org/10.1186/s41687-024-00823-8.

Copyright © 2024 The Author(s).

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

CONCLUSIONS: This analysis generated evidence supportive of the psychometric properties of the GP5 as a fit-for-purpose measure to assess treatment tolerability in patients with advanced/metastatic MTC. The definition of "high side-effect burden" was associated with the clinical feature of tolerability.

Recommended Citation

Regnault, Antoine; Bunod, Laurine; Loubert, Angely; Brose, Marcia S.; Hess, Lisa M.; Maeda, Patricia; Lin, Yan; Speck, Rebecca M.; Gilligan, Adrienne M.; and Payakachat, Nalin, "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" (2024). Department of Medical Oncology Faculty Papers. Paper 282.
https://jdc.jefferson.edu/medoncfp/282

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 License.

PubMed ID

39694978

Language

English