Qualitative Trial Interviews to Explore the Experience of Adult and Pediatric Patients Participating in a Pivotal Phase 3 Trial of DTX401 for Glycogen Storage Disease Type Ia
Author(s)
Diane M. Turner-Bowker, PhD1, Shayna Egan, MPH1, Jessica Butler, BA1, Richard Collis, MD1, Martha Gauthier, MA2, Blaise Cureg, MPH2, Adriana Voci, BS2, Manpreet K. Sidhu, PhD1, John J. Mitchell, MD3.
1Ultragenyx Pharmaceutical Inc., Novato, CA, USA, 2Lumanity, Boston, MA, USA, 3Montreal Children's Hospital, Montreal, QC, Canada.
1Ultragenyx Pharmaceutical Inc., Novato, CA, USA, 2Lumanity, Boston, MA, USA, 3Montreal Children's Hospital, Montreal, QC, Canada.
OBJECTIVES: Glycogen Storage Disease type Ia (GSDIa) is a rare, inherited, autosomal recessive disease with deficiency of glucose-6-phosphatase-α (G6PC) requiring the frequent consumption of exogenous glucose (e.g., uncooked cornstarch) for patient survival. Qualitative trial interviews explored patient treatment experiences in a Phase 3, double-blind, randomized, placebo-controlled crossover study of DTX401, an investigational gene therapy for GSDIa in patients ≥8 years (NCT05139316).
METHODS: Following ethics approval, 30-minute telephone/Zoom interviews were conducted using semi-structured interview guides at trial Week 48 (primary efficacy analysis period) and Week 96 (crossover period). Interviews were audio-recorded, and data were transcribed, coded, and content analyzed.
RESULTS: Interviews included 40 (n=22 Placebo, n=18 DTX401) participants at Week 48 and 38 (n=20 Crossover-DTX401, n=18 DTX401) participants at Week 96. Across timepoints, DTX401-treated participants most frequently reported reductions in cornstarch intake, less hypoglycemia, less tiredness, and improved physical function, social, and diet/daily regimen impacts, which were all identified as most important to treat during Baseline interviews. At Week 48, both groups reported less hypoglycemia; however, DTX401 participants more frequently reported less worry about blood sugar, improved self-regulation of blood sugar, and that it was easier to manage GSDIa at their Week 48 timepoint. DTX401 participants also more frequently described improvements in GSDIa and overall quality of life (QoL), citing reduction in cornstarch intake, improved blood sugar levels, diet liberalization, increased independence, and ability to live a more normal life. Generally, most Week 48 DTX401 group results appear sustained or improved at Week 96, while a higher proportion of Crossover-DTX401 participants reported positive outcomes at Week 96 than Week 48 (as Placebo participants). Perspectives on treatment were positive for both treatment groups at Week 48 and Week 96.
CONCLUSIONS: During qualitative interviews, adult and pediatric Phase 3 trial participants described reduced treatment burden, improvements in GSDIa, and improved overall QoL following treatment with DTX401.
METHODS: Following ethics approval, 30-minute telephone/Zoom interviews were conducted using semi-structured interview guides at trial Week 48 (primary efficacy analysis period) and Week 96 (crossover period). Interviews were audio-recorded, and data were transcribed, coded, and content analyzed.
RESULTS: Interviews included 40 (n=22 Placebo, n=18 DTX401) participants at Week 48 and 38 (n=20 Crossover-DTX401, n=18 DTX401) participants at Week 96. Across timepoints, DTX401-treated participants most frequently reported reductions in cornstarch intake, less hypoglycemia, less tiredness, and improved physical function, social, and diet/daily regimen impacts, which were all identified as most important to treat during Baseline interviews. At Week 48, both groups reported less hypoglycemia; however, DTX401 participants more frequently reported less worry about blood sugar, improved self-regulation of blood sugar, and that it was easier to manage GSDIa at their Week 48 timepoint. DTX401 participants also more frequently described improvements in GSDIa and overall quality of life (QoL), citing reduction in cornstarch intake, improved blood sugar levels, diet liberalization, increased independence, and ability to live a more normal life. Generally, most Week 48 DTX401 group results appear sustained or improved at Week 96, while a higher proportion of Crossover-DTX401 participants reported positive outcomes at Week 96 than Week 48 (as Placebo participants). Perspectives on treatment were positive for both treatment groups at Week 48 and Week 96.
CONCLUSIONS: During qualitative interviews, adult and pediatric Phase 3 trial participants described reduced treatment burden, improvements in GSDIa, and improved overall QoL following treatment with DTX401.
Conference/Value in Health Info
2025-11, ISPOR Europe 2025, Glasgow, Scotland
Value in Health, Volume 28, Issue S2
Code
PCR200
Topic
Clinical Outcomes, Patient-Centered Research
Topic Subcategory
Patient-reported Outcomes & Quality of Life Outcomes
Disease
Diabetes/Endocrine/Metabolic Disorders (including obesity), Genetic, Regenerative & Curative Therapies, Rare & Orphan Diseases