Clinically Important Improvements and Disease Stability with Fluticasone Furoate/Umeclidinium/Vilanterol Once-Daily Single-Inhaler Triple Therapy in the ELLITHE Trial: A Post Hoc Responder Analysis

Responder analyses provide information about characteristics associated with therapeutic benefits. Short-term responses may predict long-term benefits. We evaluated responders, clinically important improvement (CII), disease stability (DS), and the relation of short- to long-term responses in patients with chronic obstructive pulmonary disease (COPD) in ELLITHE. ELLITHE was a multicenter, open-label, non-interventional effectiveness study between 2020 and 2022 evaluating the effects of treatment initiation with once-daily single-inhaler triple therapy (odSITT) FF/UMEC/VI (100/62.5/25 µg via ELLIPTA) on COPD Assessment Test (CAT), forced expiratory volume in 1 s (FEV1), and exacerbations over 12 months. Post hoc responder analyses for CAT (≥ 2 units improvement), FEV1 (≥ 100 ml change), and exacerbations (no event) were performed. Composite endpoints CII and DS (CII = response to at least two outcomes; DS = absence of clinically important deterioration for all outcomes) were also evaluated. A total of 786 patients had available data for any analysis. At study completion, 53.3% of patients were CAT, 36.7% FEV1, and 90.2% exacerbation responders, with 22.1% responding to all outcomes; 64.3% had a CII, and 52.7% showed DS. CII and DS were more frequent in subjects with higher baseline CAT score, and DS in patients on prior ICS/LABA therapy (all p < 0.05). Early (3 months) CAT, FEV1 and CII response strongly predicted respective responses at study end (odds ratios = OR ranging from 6.3 to 7.4), and DS (OR from 3.0 to 4.2). In the patient subset with available baseline eosinophil counts, response was generally similar at < 150 versus ≥ 150 cells/μl. Despite overlapping responses to single and composite outcomes with odSITT, individual patterns support a multidimensional approach to evaluate benefits in COPD. Responders had higher baseline CAT scores and frequency of prior dual therapies. Short-term responses of FEV1 and/or CAT were reasonable predictors of long-term responses, including DS. DS was achievable for the majority of patients and may represent a useful outcome for future COPD research and management.