Rituximab treatment is more effective than cyclophosphamide in GPA

Treatment with rituximab is superior to cyclophosphamide in achieving remission in patients with granulomatosis with polyangiitis (GPA), according to a single-center study in Iran.

Although the safety profiles of the two treatments were comparable, the rituximab treatment was more effective, the study found. Specifically, nearly 90% of patients treated with rituximab achieved disease remission within six months, compared to 68% of those treated with cyclophosphamide.

“By emphasizing the superiority of [rituximab] including remission, we may be able to improve patient outcomes and guide treatment decisions,” the researchers wrote.

The study, “Comparison of Rituximab and Cyclophosphamide for induction therapy in patients with granulomatosis with polyangiitis.,” was published as a letter to the editor at International Journal of Rheumatic Diseases.

Both rituximab and cyclophosphamide are used in the treatment of AAV

GPA is a form of ANCA-associated vasculitis (AAV), a group of autoimmune diseases characterized by inflammation and destruction of small blood vessels that are often associated with autoantibodies called ANCAs. This common type is often characterized by symptoms affecting the respiratory tract and kidneys.

Currently available AAV treatments aim to induce remission, which is temporarily asymptomatic, and maintain remission. These immunosuppressive drugs mainly consist of glucocorticoids combined with cyclophosphamide or rituximab.

Cyclophosphamide (marketed as Cytoxan and others, with generics available) has long been used for AAV off-label. Meanwhile, rituximab (marketed as Rituxan in the US and Japan, with biosimilars available) was approved more than a decade ago in the US for the treatment of GPA and microscopic polyangiitis (MPA ), two common types of AAV. It is available both as induction therapy and as maintenance therapy.

Data from previous trials have shown comparable treatment responses between patients treated with rituximab and cyclophosphamide. However, in the real world, data comparing both treatments in GPA patients are limited.

Now, researchers at Tehran University of Medical Sciences evaluated the safety and efficacy of rituximab as induction therapy versus cyclophosphamide among GPA patients followed at their institution between 2016 and 2020.

During that time, 155 adults were diagnosed with GPA and had complete medical records. A total of 29 rituximab-treated patients and 28 cyclophosphamide-treated patients matched for age, sex, disease severity, organ involvement, and ANCA type at study initiation were included in the analysis. last.

The primary outcome measure was to evaluate disease healing rates after six months of implant therapy. Mortality reduction was defined as a score of zero on the Birmingham Vasculitis Activity Score for Wegener granulomatosis (BVAS/WG), and a dose of prednisolone, a glucocorticoid, up to 10 mg.

The results showed that the proportion of patients who achieved remission was higher in the rituximab group than in the cyclophosphamide group (89.7% vs. 67.9%).

Overall, our study suggests so [rituximab] shows greater success [cyclophosphamide] for induction therapy in GPA patients while maintaining the same level of safety. … Therefore, [rituximab] is the preferred choice for induction therapy in GPA patients.

The presence of ANCAs against proteinase 3 (PR3), the common target of these autoantibodies – found in 58.6% of patients treated with rituximab and 46.4% of those treated with cyclophosphamide – was associated with low effectiveness of treatment.

In particular, among those positive for anti-PR3 ANCAs, approximately 76.5% of those on rituximab and 53.8% of those on cyclophosphamide achieved disease remission.

The most commonly reported complication during the six-month follow-up in both treatment groups was infection, with similar rates in both patient groups.

“In general, our study suggests that [rituximab] shows greater success [cyclophosphamide] for induction therapy in GPA patients while maintaining the same level of safety,” the researchers wrote. “Therefore, [rituximab] is the preferred choice for induction therapy in GPA patients. ”

However, the team noted that “the results should be treated with caution” due to the retrospective nature of the study and the small number of patients included.