BACKGROUND: Rituximab, an anti-CD20 B-cell depleting monoclonal antibody, is 
increasingly prescribed off-label for a range of autoimmune diseases. There has 
not previously been an audit of off-label rituximab use in the Northern 
Territory, where the majority of patients are Aboriginal.
AIMS: To evaluate retrospectively off-label rituximab use in autoimmune diseases 
in the Top End of the Northern Territory.
METHODS: We performed a retrospective audit of 8 years of off-label rituximab 
use at the Royal Darwin Hospital, the sole tertiary referral centre for the 
Darwin, Katherine and East Arnhem regions. Electronic and paper records were 
reviewed for demographic information, diagnosis/indication for rituximab, doses, 
previous/concomitant immunosuppression, clinical outcomes and specific adverse 
events.
RESULTS: Rituximab was prescribed off-label to 66 patients for 24 autoimmune 
diseases. The majority of patients (62.1%) were Aboriginal and 60.6% female. The 
most common indications were refractory/relapsing disease despite standard 
therapies (68.7%) or severe disease with rituximab incorporated into an 
induction immunosuppressive regimen (19.4%). Systemic lupus erythematosus was 
the underlying diagnosis in 28.8% of cases. A clinically significant response 
was demonstrated in 74.2% of cases overall. There were 18 clinically significant 
infections; however, 13 were in patients receiving concurrent immunosuppressive 
therapy. There was a total of nine deaths from any cause.
CONCLUSION: Rituximab has been used off-label for a range of autoimmune diseases 
in this population with a high proportion of Aboriginal patients successfully 
and safely in the majority of cases.