PIH70 exploring variability in Patient-Reported Pain and Treatment Efficacy in Patients with Endometriosis

Abstract

Objectives To explore variability in patient-reported pain and potential differential treatment response in clinical studies among patients with endometriosis.

Methods Data came from two clinical studies of daily oral dienogest for treatment of endometriosis: study 307041 (dienogest 2 mg / day arm only over 12 weeks; n=102); and study 97085 (dienogest 2 mg / day versus leuprorelin acetate 3.75 mg / 4 weeks over 24 weeks; n=252). Heterogeneity of patient responses on the Bodily Pain (BP) domain of the SF-36v2 at both baseline and the follow-up time point were analysed using latent transition analysis (LTA) regardless of treatment group. The model combined cross-sectional measurement of latent (i.e., unobserved) variables and the longitudinal description of change in the latent variable over time. The latent-class variables identified data-driven subgroups based on the similarity of responses on the BP domain. One latent-class variable was identified for the baseline time point; a second latent-class variable was identified for the follow-up time point. Demographic and clinical characteristics were investigated between identified subgroups.

Results Large variability around mean BP was observed in both trials. In study 97085, 4 potential subgroups with differential response were identified: 3 of these showed improvement across the 24-week period (mean improvement range = 10.8 to 52.7) and were comprised of 92% of patients (n=232); the remaining 8% (n=16) showed a reduction (worsening) of BP scores from a mean (SD) of 36.9 (23.4) to 24.1 (11.5). In study 307041, 2 subgroups were identified: all patients improved across the 12 week period (mean improvement range: 12.3 to 45.2). Variables that were significantly related to subgroup membership included endometriosis-associated pelvic pain and concomitant analgesic use.

Conclusions While variability in treatment response is high, pain was relieved for most patients. Presence and causality of differential response to endometriosis treatments require more research including cross-over studies.