Infusion reaction rates to rituximab may be more significant among patients with systemic lupus erythematosus than other diseases, according to findings published in BMC Rheumatology.
“There would obviously be a clear benefit in identifying those patients most at risk of developing significant adverse reactions and understanding the precise mechanism of individual [infusion reactions],” Ashleigh Hennessey, MBBS, FRACP, of the University of Queensland School of Medicine, Brisbane, Australia, and colleagues wrote. “This would allow more targeted treatment and risk assessment and therefore help guide decisions regarding retreatment of individual patients. There are now well-established desensitization protocols for patients who have a true hypersensitivity reaction to [rituximab], which could potentially allow retreatment with this often highly effective drug for SLE.”
To determine the rates of clinically significant adverse infusion reactions to rituximab (Rituxan, Genentech) among patients with SLE, Hennessey and colleagues conducted a retrospective analysis of the entire cohort of patients with the disease at University College London Hospitals who received the drug from June 2000 to May 2016. The researchers examined patient files and medical records, including clinic letters and discharge summaries, for the presence of significant reactions for each rituximab infusion.
Among the information analyzed in the study included details of the nature and timing of each reaction, as well as the decision-making process regarding patient management. To differentiate between cytokine release or antibody mediated reactions, the researchers considered the timing on reaction onset, signs and symptoms, response to treatment and whether treatment was required to control the infusion reaction. They also collected data on patients’ demographics, organ involvement and autoantibody information, retreatments and subsequent infusions.
Hennessey and colleagues analyzed the records of 136 patients with SLE. However, 11 patients, representing 21 cycles, were excluded due to missing information, providing a total of 481 individual rituximab infusions across 125 patients, including 118 women and seven men.
According to the researchers, 17.6% of patients experienced 28 documented clinically significant infusion reactions, accounting for 5.8% of total infusions. The average age at first infusion with rituximab among patients without a reaction was 37 years, compared with 30 years among those who experienced a reaction. In addition, 18.2% of men included in the study experienced an infusion reaction. Among the documented reactions, 17.9% involved cutaneous rash, flushing and generalized pruritus. There were six cases, accounting for 21.4% of reactions, in which the adverse event occurred 48 hours after the infusion. There was one death. A total of 6.4% of those who had a reaction were not retreated.
“Rates of [infusion reactions] to [rituximab] appear to be more significant than in SLE than in other disease cohorts,” Hennessey and colleagues wrote. “They can occur at any time during individual treatments and during different cycles and are likely to have several different underlying etiologies. In our cohort reactions were more common in men. Further prospective studies are needed to establish relevant mechanisms, and hence best practice for treatment and prevention.” – by Jason Laday
Disclosure: Hennessey reports financial support to attend international conferences from Bristol Myers Squibb. Please see the full study for additional authors’ disclosures.