Rituximab, initially developed to treat certain types of cancer, is increasingly being used “off-label” to treat patients with cold agglutinin disease (CAD), a rare autoimmune disorder, according to a retrospective study published in EJHaem in July 2025.
The study, conducted by researchers at the USC Norris Comprehensive Cancer Center and Montefiore Medical Center/Albert Einstein College of Medicine, examined treatment patterns and safety outcomes associated with rituximab use in the United States. Researchers Caroline Piatek of USC and Irina Murakhovskaya of Montefiore led the study, which involved analysis of patient data. The research team likewise included members from Sanofi, Aetion and BMAPS SARL.
CAD is an autoimmune hemolytic anemia where antibodies attack red blood cells at low temperatures. Conventional therapies for the disease have proven largely ineffective, prompting clinicians to explore alternative treatments like rituximab, an anti-CD20 antibody. A prospective trial involving 27 patients and 37 courses of rituximab showed that 14 of the 27 patients responded to their first course of treatment, according to research published in Blood.
The EJHaem study highlights the limited real-world data available on rituximab’s use for CAD, despite its growing adoption. The retrospective analysis aimed to address this gap by evaluating treatment patterns and identifying potential safety concerns. The study’s findings contribute to a growing body of evidence supporting the use of rituximab in CAD, although further research is needed to fully understand its long-term efficacy and safety profile.
A case reported on coldagglutininnews.com details the successful use of rituximab in a rare instance of a dual autoimmune blood disorder, further illustrating the potential of the drug in complex autoimmune conditions.
The National Institutes of Health notes that CAD is associated with autoimmune phenomena, but does not involve underlying aggressive lymphoma, malignancies, or specific infections.
