Rituximab should be considered an alternative treatment option to cyclophosphamide for treating interstitial lung disease (ILD) associated with connective tissue disease (CTD), according to researchers whose trial showed improvements in FVC and quality of life.

Data from the retrospective RECITAL trial, published in The Lancet Respiratory Medicine, showed that while rituximab was not superior to cyclophosphamide it was comparable on safety and efficacy, according to UK respiratory consultant Professor Toby Maher.

Presneting the results at the ACR 2022 meeting in Philadelphia he noted that while cyclophosphamide was standard of care for CTD-ILD patients the treatment had “challenges” such as tolerance and bladder cancer risks, creating a need for alternative treatment options. Furthermore, although rituximab was used in clinical practice for the treatment of CTD-ILD, no evidence base existed to guide therapy.

 The RECITAL trial involved 101 participants with severe or progressive ILD linked with idiopathic inflammatory myositis (IIM), systemic sclerosis (SSc) or mixed connective tissue disease (MCTD) were randomly assigned to receive either cyclophosphamide (50) or rituximab (51).

Forty-three participants in the cyclophosphamide group and 42 in the rituximab arm completed 24 weeks of treatment and follow-up.

At 24 weeks, FVC was improved from baseline in both the cyclophosphamide group (unadjusted mean increase 99mL; +5%) and the rituximab group (97 mL; +4%), showing that each drug “almost certainly had a patient benefit”, delegates heard.

Also, KBILD quality-of-life scores were improved at 24 weeks by a mean 9.4 points versus 8.8 points, respectively, while lower corticosteroid exposure over 48 weeks of follow-up was observed in the rituximab arm.

“Overall survival, progression-free survival, and time to treatment failure did not significantly differ between the two groups,” and “numerically fewer adverse events were reported by participants receiving rituximab (445 events) than those receiving cyclophosphamide (646 events),” according to the authors who said the results were “important” for patients with CTD-ILD and clinicians involved in their treatment.

“The improvements in FVC and quality of life at 24 weeks following administration of rituximab suggest that the drug offers an effective treatment option for this group of patients,” said the study authors, which included Professor Christopher Denton, a Professor of Experimental Rheumatology at UCL and Consultant Rheumatologist.

“Furthermore, rituximab appeared to be better tolerated and associated with lower corticosteroid use than cyclophosphamide, the existing first-line treatment option for CTD-ILD”, they added.