Treatment with abatacept observed to be effective in some forms of vasculitis, but not all.
Two new studies published by Arthritis & Rheumatology revealed new information regarding vasculitis, which may lead to improved treatment methods.
Vasculitis is a group of conditions that cause blood vessels to become inflamed, and can cut off blood supply to vital organs and tissues.
The investigators set out to determine if a drug that impacts T cells would effectively treat the most common and the rarest forms of vasculitis, which both affect large blood vessels.
In the studies, patients were initially treated with prednisone and abatacept, which affects T cells. After 12 weeks of treatment, the patients were then randomized to receive abatacept or placebo. The patients underwent prednisone tapering, with treatment fully discontinued at 28 weeks, according to the study.
There were 41 patients with new or relapsing giant cell arteritis (GCA)— the most common form of vasculitis— included in the first trial, and 26 patients with Takayasu’s arteritis (TAK)— one of the rarest forms—included in the second trail.
In the trial of GCA, 48% of patients treated with abatacept were relapse-free at 12 months, while only 31% of patients in the placebo group were relapse-free, according to the study.
Patients treated with abatacept were in remission for a median of 9.9 months, while patients treated with placebo were only in remission for a median of 3.9 months.
"Prednisone is effective but associated with significant potential side effects, particularly in the older population who are affected by this disease. As relapses occur frequently in GCA, this has often meant that patients require repeated courses of prednisone," said lead author Carol Langford, MD, MHS. "The results from this study are encouraging and could lead to a novel treatment option in people with GCA."
In the trial of TAK, the opposite effects were discovered. At 12 months, only 22% of patients taking abatacept were relapse-free, while 40% of patients in the placebo group were relapse-free.
Abatacept was also not linked to longer duration for patients with TKA. Patients treated with placebo were in remission for 5.7 months, and patients treated with abatacept only remained in remission for 5.5 months, according to the study.
"This study was important in being the first international trial that compared two different treatment approaches in TAK to determine which was more effective," Dr Langford said. "Although abatacept was not found to provide additional benefit beyond prednisone, the study was very significant in how it was conducted and what was learned. By demonstrating that comparative studies in TAK are possible, this work will advance future investigations of novel treatment approaches in people with TAK."
The authors said that there were no differences in adverse events between patients in either trial. They also noted that the studies were designed to be conducted by the same team of investigators who use the same study protocol.
"This approach was taken with the goal of exploring the similarities and differences between these two forms of large-vessel vasculitis," Dr Langford concluded. "The observation of contrasting results raises intriguing questions about these diseases and highlights the importance of continued research in vasculitis."