STRUCTURAL EQUATION MODELING (SEM) OF PATIENT SATISFACTION WITH ISATUXIMAB ADMINISTRATION: PERCEIVED TIME SAVINGS AND A LATENT INJECTION EXPERIENCE CONSTRUCT INDEPENDENTLY PREDICTED SATISFACTION
Author(s)
James Marcus, PhD1, Donald Stull, PhD2, Alexia Tellier, MSc3, Maeva Kyheng, PhD4, Perman Gochyyev, PhD5, Jérôme Msihid, MSc3, Maya Stefanova-Urena, MD5, Florence Suzan Teisserenc, MD6, Benoit Arnould, PhD7.
1IQVIA, Washington, DC, USA, 2IQVIA, Port Townsend, WA, USA, 3Sanofi, Gentilly, France, 4Aixial Group, Boulogne-Billancourt, France, 5Sanofi, Morristown, NJ, USA, 6Sanofi, Vitry-sur-Seine, France, 7Sanofi, Lyon, France.
1IQVIA, Washington, DC, USA, 2IQVIA, Port Townsend, WA, USA, 3Sanofi, Gentilly, France, 4Aixial Group, Boulogne-Billancourt, France, 5Sanofi, Morristown, NJ, USA, 6Sanofi, Vitry-sur-Seine, France, 7Sanofi, Lyon, France.
OBJECTIVES: In the IRAKLIA phase 3 trial (NCT05405166) of patients with relapsed/refractory multiple myeloma, the 9-item Patient Experience and Satisfaction Questionnaire Follow-Up (PESQ-FU) captured treatment- and injection-related attributes across isatuximab administration routes. Item 8 assessed injection satisfaction using a single 5-point ordinal item. Subcutaneous administration of isatuximab via an on-body injector showed higher satisfaction than intravenous delivery at C5D15 (70.0% vs 53.4%). A structural equation modeling (SEM) analysis evaluated whether injection satisfaction reflected distinct contributions of injection experience and perceived time savings.
METHODS: SEM was conducted in the IRAKLIA intent-to-treat population with PESQ-FU data at C5D15. The model was guided by theory, observed associations from prior psychometric analyses, and predictors identified in logistic regression. Injection experience was modeled as a 3-item latent construct: discomfort (Item 1), pain (Item 2), and injection side effects (Item 4). Injection satisfaction (Item 8) was the observed endogenous outcome predicted by Injection Experience and time saved (Item 5). Model fit was assessed using standard fit indices (CFI/TLI, SRMR, RMSEA).
RESULTS: The SEM analysis included 392 patients and showed strong model fit (CFI=0.998; TLI=0.994; RMSEA=0.020; SRMR=0.014). Factor loadings supported the Injection Experience construct: discomfort=0.721, pain=0.909, and injection side effects=0.602. Standardized path coefficients (β) showed that time saved and Injection Experience significantly predicted injection satisfaction (β=0.481 and β=0.277, respectively), with time saved showing the stronger association. Both were weakly correlated (r=0.170), supporting their interpretation as related but distinct aspects of the patient experience. Together, they explained 35% of the variance in injection satisfaction.
CONCLUSIONS: SEM indicated that patient satisfaction with isatuximab administration reflected both perceived time savings and a latent Injection Experience construct. Perceived time savings showed the stronger independent association with satisfaction. These findings support considering convenience-related treatment attributes alongside injection-local tolerability when interpreting patient-reported satisfaction with administration.
METHODS: SEM was conducted in the IRAKLIA intent-to-treat population with PESQ-FU data at C5D15. The model was guided by theory, observed associations from prior psychometric analyses, and predictors identified in logistic regression. Injection experience was modeled as a 3-item latent construct: discomfort (Item 1), pain (Item 2), and injection side effects (Item 4). Injection satisfaction (Item 8) was the observed endogenous outcome predicted by Injection Experience and time saved (Item 5). Model fit was assessed using standard fit indices (CFI/TLI, SRMR, RMSEA).
RESULTS: The SEM analysis included 392 patients and showed strong model fit (CFI=0.998; TLI=0.994; RMSEA=0.020; SRMR=0.014). Factor loadings supported the Injection Experience construct: discomfort=0.721, pain=0.909, and injection side effects=0.602. Standardized path coefficients (β) showed that time saved and Injection Experience significantly predicted injection satisfaction (β=0.481 and β=0.277, respectively), with time saved showing the stronger association. Both were weakly correlated (r=0.170), supporting their interpretation as related but distinct aspects of the patient experience. Together, they explained 35% of the variance in injection satisfaction.
CONCLUSIONS: SEM indicated that patient satisfaction with isatuximab administration reflected both perceived time savings and a latent Injection Experience construct. Perceived time savings showed the stronger independent association with satisfaction. These findings support considering convenience-related treatment attributes alongside injection-local tolerability when interpreting patient-reported satisfaction with administration.
Conference/Value in Health Info
2026-11, ISPOR Europe 2026, Vienna, Austria
Value in Health, Volume 29, Issue 12S
Code
PT17
Topic
Clinical Outcomes, Methodological & Statistical Research, Patient-Centered Research
Topic Subcategory
PRO & Related Methods
Disease
No Additional Disease & Conditions/Specialized Treatment Areas, Oncology