Rituximab versus intravenous cyclophosphamide in patients with connective tissue disease-associated interstitial lung disease in the UK (RECITAL): a double-blind, double-dummy, randomised, controlled, phase 2b trial.

BACKGROUND: Rituximab is often used as rescue therapy in interstitial lung disease (ILD) associated with connective tissue disease (CTD), but has not been studied in clinical trials. This study aimed to assess whether rituximab is superior to cyclophosphamide as a treatment for severe or progressive CTD associated ILD. METHODS: We conducted a randomised, double-blind, double-dummy, phase 2b trial to assess the superiority of rituximab compared with cyclophosphamide. Patients aged 18-80 years with severe or progressive ILD related to scleroderma, idiopathic inflammatory myositis, or mixed CTD, recruited across 11 specialist ILD or rheumatology centres in the UK, were randomly assigned (1:1) to receive rituximab (1000 mg at weeks 0 and 2 intravenously) or cyclophosphamide (600 mg/m2 body surface area every 4 weeks intravenously for six doses). The primary endpoint was rate of change in forced vital capacity (FVC) at 24 weeks compared with baseline, analysed using a mixed-effects model with random intercepts, adjusted for baseline FVC and CTD type. Prespecified secondary endpoints reported in this Article were change in FVC at 48 weeks versus baseline; changes from baseline in 6 min walk distance, diffusing capacity of the lung for carbon monoxide (DLCO), physician-assessed global disease activity (GDA) score, and quality-of-life scores on the St George's Respiratory Questionnaire (SGRQ), King's Brief Interstitial Lung Disease (KBILD) questionnaire, and European Quality of Life Five-Dimension (EQ-5D) questionnaire at 24 and 48 weeks; overall survival, progression-free survival, and time to treatment failure; and corticosteroid use. All endpoints were analysed in the modified intention-to-treat population, which comprised all patients who received at least one dose of study drug. This trial is registered with ClinicalTrials.gov (NCT01862926). FINDINGS: Between Dec 1, 2014, and March 31, 2020, we screened 145 participants, of whom 101 participants were randomly allocated: 50 (50%) to receive cyclophosphamide and 51 (50%) to receive rituximab. 48 (96%) participants in the cyclophosphamide group and 49 (96%) in the rituximab group received at least one dose of treatment and were included in analyses; 43 (86%) participants in the cyclophosphamide group and 42 (82%) participants in the rituximab group completed 24 weeks of treatment and follow-up. At 24 weeks, FVC was improved from baseline in both the cyclophosphamide group (unadjusted mean increase 99 mL [SD 329]) and the rituximab group (97 mL [234]); in the adjusted mixed-effects model, the difference in the primary endpoint at 24 weeks was -40 mL (95% CI -153 to 74; p=0·49) between the rituximab group and the cyclophosphamide group. KBILD quality-of-life scores were improved at 24 weeks by a mean 9·4 points (SD 20·8) in the cyclophosphamide group and 8·8 points (17·0) in the rituximab group. No significant differences in secondary endpoints were identified between the treatment groups, with the exception of change in GDA score at week 48, which favoured cyclophosphamide (difference 0·90 [95% CI 0·11 to 1·68]). Improvements in lung function and respiratory-related quality-of-life measures were observed in both treatment groups. Lower corticosteroid exposure over 48 weeks of follow-up was recorded in the rituximab group. Two (4%) of 48 participants who received cyclophosphamide and three (6%) of 49 who received rituximab died during the study, all due to complications of CTD or ILD. Overall survival, progression-free survival, and time to treatment failure did not significantly differ between the two groups. All participants reported at least one adverse event during the study. Numerically fewer adverse events were reported by participants receiving rituximab (445 events) than those receiving cyclophosphamide (646 events). Gastrointestinal and respiratory disorders were the most commonly reported adverse events in both groups. There were 62 serious adverse events of which 33 occurred in the cyclophosphamide group and 29 in the rituximab group. INTERPRETATION: Rituximab was not superior to cyclophosphamide to treat patients with CTD-ILD, although participants in both treatment groups had increased FVC at 24 weeks, in addition to clinically important improvements in patient-reported quality of life. Rituximab was associated with fewer adverse events. Rituximab should be considered as a therapeutic alternative to cyclophosphamide in individuals with CTD-ILD requiring intravenous therapy. FUNDING: Efficacy and Mechanism Evaluation Programme (Medical Research Council and National Institute for Health Research, UK).

The need for a holistic approach for SSc-ILD - achievements and ambiguity in a devastating disease.

Systemic sclerosis (SSc) is a multi-organ autoimmune disease with complex interactions between immune-mediated inflammatory processes and vascular pathology leading to small vessel obliteration, promoting uncontrolled fibrosis of skin and internal organs. Interstitial lung disease (ILD) is a common but highly variable manifestation of SSc and is associated with high morbidity and mortality. Treatment approaches have focused on immunosuppressive therapies, which have shown some efficacy on lung function. Recently, a large phase 3 trial showed that treatment with nintedanib was associated with a reduction in lung function decline. None of the conducted randomized clinical trials have so far shown convincing efficacy on other outcome measures including quality of life determined by patient reported outcomes. Little evidence is available for non-pharmacological treatment and supportive care specifically for SSc-ILD patients, including pulmonary rehabilitation, supplemental oxygen, symptom relief and adequate information. Improved management of SSc-ILD patients based on a holistic approach is necessary to support patients in maintaining as much quality of life as possible throughout the disease course and to improve long-term outcomes.

Pharmacological Treatment of Idiopathic Pulmonary Fibrosis: Current Approaches, Unsolved Issues, and Future Perspectives.

Idiopathic pulmonary fibrosis (IPF) is a devastating condition with a 5-year survival of approximately 20%. The disease primarily occurs in elderly patients. IPF is a highly heterogeneous disorder with a clinical course that varies from prolonged periods of stability to episodes of rapid deterioration. In the last decade, improved understanding of disease mechanisms along with a more precise disease definition has allowed the design and completion of a number of high-quality clinical trials. Yet, until recently, IPF was essentially an untreatable disease. Finally, pirfenidone and nintedanib, two compounds with antifibrotic properties, have consistently proven effective in reducing functional decline and disease progression in IPF. This is a major breakthrough for patients and physicians alike, but there is still a long way to go. In fact, neither pirfenidone nor nintedanib is a cure for IPF, and most patients continue to progress despite treatment. As such, comprehensive care of patients with IPF, including management of comorbidities/complications and physical debility and timely referral for palliative care or, in a small number of highly selected patients, lung transplantation, remains essential. Several agents with high potential are currently being tested and many more are ready to be evaluated in clinical trials.