OBJECTIVES: The EQ-5D is a generic preference-based measure of HRQoL, which may not fully capture health-related impacts of certain diseases. KarMMa-3 (NCT03651128), a Phase-3 randomized clinical trial, reported meaningful HRQoL improvements for patients receiving idecabtagene vicleucel versus standard regimens with the EORTC QLQ-C30, EORTC QLQ-MY20, and EQ-5D visual analogue scale. Utilizing KarMMa-3 HRQoL data, this study compared the sensitivity of health state utility values (HSUVs) to treatment effect, based on the EQ-5D-3L crosswalked from EQ-5D-5L (van Hout et al. 2012) and EQ-5D-3L mapped from EORTC QLQ-C30 with/without MY20.

METHODS: A targeted literature review identified five mapping algorithm publications for EORTC QLQ-C30 with/without MY20 to EQ-5D-3L in MM patients, of which three allowed for a UK tariff: Longworth et al. 2014 (EORTC QLQ-C30), Proskorovsky et al. 2014 (EORTC QLQ-C30 with/without MY20), and Kharroubi et al. 2015 (EORTC QLQ-C30 with MY20). Only Longworth and Proskorovsky were validated and used in previous MM reimbursement submissions. A linear mixed effects model to account for repeated measures was used to estimate treatment-specific HSUVs for progression-free (PF) and a combined HSUV for progressed disease (PD), assuming a UK tariff.

RESULTS: Longworth resulted in PF utilities of 0.744 (standard error [SE] 0.008) for idecabtagene vicleucel and 0.721 (SE 0.010) for standard regimens, and a PD utility of 0.650 (SE 0.012). The remaining algorithms showed similar trends, with higher absolute values from Proskorovsky and lower absolute values from Kharroubi. All mapping algorithm modelled PF utilities resulted in a statistically significant treatment effect (p<0.05) compared to crosswalked EQ-5D-3L (p=0.370). The greatest difference between PF treatment-specific utilities was observed with Kharroubi (Δ 0.036), compared to crosswalked EQ-5D-3L (Δ 0.008).

CONCLUSIONS: The EQ-5D may not capture myeloma-specific elements most important to patients with TCE RRMM. Decision-makers should consider HSUVs from disease-specific measures to fully capture improvements in HRQoL with new interventions.