AAV add-on therapy cuts steroid use, doesn’t boost kidney health

People with ANCA-associated vasculitis (AAV) and severe kidney damage did not see better kidney outcomes with rituximab plus Tavneos (avacopan) than with rituximab alone, a study found.

However, the results showed that adding Tavneos to rituximab may help limit the use of glucocorticoids, which can have serious long-term side effects.

“In our [group] of patients with AAV and severe [kidney] involvement treated with rituximab-based induction, [add-on Tavneos] did not improve [kidney health outcomes] … but achieved significant and faster glucocorticoid reduction with an acceptable safety profile,” the researchers wrote.

The study, “Rituximab With or Without Avacopan in ANCA-Associated Vasculitis With Severe Renal Involvement,” was published in Kidney International Reports.

AAV is an autoimmune disease marked by inflammation in small blood vessels, which can damage the kidneys and other organs. AAV is caused in most cases by self-reactive antibodies, called ANCAs, that target proteins in certain immune cells.

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Treatments work in different ways

Rituximab and Tavneos are AAV treatments for approved for granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA), the two most common types of AAV. While the two therapies broadly aim to reduce the abnormal immune system activity that drives AAV, they work via different mechanisms.

Rituximab (sold as Rituxan, MabThera, and generics) is designed to kill antibody-producing B-cells, while Tavneos works by suppressing a part of the immune system that contributes to AAV-related small blood vessel damage.

Each therapy is typically given in combination with glucocorticoids as an induction treatment, intended to achieve disease remission. However, because of glucocorticoids’ known side effects, patients typically undergo a glucocorticoid taper to reduce the dose or stop the medication altogether.

An international team of researchers said they wanted to see if combining rituximab and Tavneos led to better kidney outcomes than rituximab alone in people with AAV and severe kidney dysfunction, “and secondarily to evaluate its glucocorticoid-sparing effect and safety profile in this severe subgroup.”

They retrospectively analyzed data from 150 people with severe kidney damage due to AAV: 120 received rituximab alone, and 30 were given rituximab plus Tavneos. All were treated at Mayo Clinic sites between 2010 and 2025. Demographic and clinical features, including kidney disease severity, were balanced between the two treatment groups.

Results showed that kidney health outcomes did not differ significantly between the two groups. Safety findings were also largely comparable.

However, patients given add-on Tavneos had a markedly reduced need for glucocorticoids. Most were able to stop glucocorticoids within four months, whereas most patients treated with rituximab alone continued glucocorticoids for more than seven months.

“In patients with AAV and severe [kidney] involvement treated with rituximab-based induction, the addition of [Tavneos] was associated with significantly lower glucocorticoid exposure and faster discontinuation, but did not improve [kidney health measures] compared with rituximab alone,” the researchers wrote.

The scientists stressed that the study was limited by its small sample size and retrospective design, noting that further research will be needed to better understand the benefits of add-on Tavneos in people with severe AAV.

Regulatory agencies in the U.S. and European Union have recommended that Tavneos be withdrawn following allegations of manipulated data in its regulatory application and concerns about the therapy’s benefit-risk ratio.

While some clinical trial data have suggested that AAV patients with severe kidney involvement may benefit from Tavneos treatment, “our real-world findings add evidence in this specific population, showing that while adding [Tavneos] reduces glucocorticoid exposure, it does not improve kidney outcomes,” the researchers concluded.

“These findings raise questions about the additive [kidney] benefit of [Tavneos] in this particularly severe subgroup and highlight the need for [appropriately controlled] trials to define its optimal role in patients with severe AAV,” the scientists concluded.