Efficacy of rituximab versus cyclophosphamide in connective tissue disease‑related interstitial lung disease: a systematic review and meta-analysis.

OBJECTIVE

This study systematically compares the efficacy and adverse events of rituximab (RTX) and cyclophosphamide (CYC) in patients with connective tissue disease-related interstitial lung disease (CTD-ILD).

METHODS

The EMBASE, Cochrane, and PubMed databases were systematically searched to find all relevant studies. Quality assessment, study selection, and data extraction were independently conducted by two reviewers. The mean changes in percentage of predicted forced vital capacity (FVC%) and percentage of predicted diffusing capacity for carbon monoxide (DLco%) of the patients were selected to be primary outcome measures. RevMan 5 software was used for the pooled analysis.

RESULTS

Among 1106 titles screened from multiple databases, six studies met the inclusion criteria (two randomized controlled trials and four retrospective observational studies). Patients of four studies were systemic sclerosis-related interstitial disease(SSc-ILD), one study was anti-synthetase syndrome-related interstitial lung disease (AsyS-ILD), and one study was CTD-ILD (included idiopathic inflammatory myositis (IIM), systemic sclerosis (SSc) or mixed connective tissue disease (MCTD), rheumatoid arthritis(RA)). The summary weight mean difference of FVC% change in the RTX group compared with the CYC group was 0.86 (95% CI:-1.51,3.24; P = 0.48), and the summary weight mean difference of DLco% change in the RTX group compared with the CYC group was 6.43 (95% CI: 1.62, 11.23; P = 0.009). Our pooled analysis suggested no significant difference in FVC% improvement between RTX and CYC. RTX seems to be slightly superior to CYC in terms of DLco% improvement in our meta-analysis. However, only three out of six enrolled studies provided data on DLco% change. Therefore, the results for DLco% change should be cautiously interpreted. Studies enrolled showed that adverse events were fewer in the RTX group. RTX appears to offer a favorable balance between efficacy and safety.

CONCLUSIONS

RTX demonstrated similar efficacy to CYC in improving lung function (FVC% and DLco%), with fewer adverse events.