A recent clinical trial has revealed that a limited course of the experimental monoclonal antibody ianalumab may significantly improve outcomes for patients with primary immune thrombocytopenia (ITP), an autoimmune disorder that can lead to severe bleeding. In the study, more than half of the participants maintained safe platelet counts for at least one year without experiencing serious bleeding episodes. The findings were published in the New England Journal of Medicine and were presented at the 67th American Society of Hematology (ASH) Annual Meeting in Orlando, Florida.
ITP occurs when the immune system mistakenly attacks platelets, blood cells essential for clotting. It affects approximately 50,000 people in the United States and can manifest at any age. Symptoms include abnormal bleeding from the skin and mucous membranes, such as nosebleeds, gum bleeding, and heavy menstruation. In severe cases, low platelet counts can lead to significant bruising and fatigue. While some patients may not require treatment, those with low platelet counts or recurrent bleeding typically begin with steroid therapies. However, these treatments do not work for everyone, necessitating alternative options.
Current second-line treatment options approved by the FDA, while effective, often require lifelong management, either through daily medication or weekly injections. These treatments can result in various side effects and financial burdens. Dr. Adam Cuker, MD, MS, section chief for Hematology and clinical director of the Penn Blood Disorders Center, noted the limitations of existing therapies. He emphasized that the study’s results provide a significant advantage for patients by demonstrating that durable responses without ongoing therapy are achievable.
Details of the Clinical Trial
The double-blind, multicenter clinical trial, known as the VAYHIT2 study, involved 152 adult patients with ITP. Participants were randomly assigned to receive either a higher-dose of ianalumab, a lower-dose, or a placebo. Ianalumab operates by targeting the B-cell-activating factor (BAFF) receptor, which leads to a reduction in autoreactive B cells responsible for the anti-platelet antibodies that trigger ITP.
Eligible patients had either relapsed after steroid treatment or had not responded to steroids. The study protocol involved administering ianalumab intravenously once a month for four months. To facilitate the transition, all participants also received eltrombopag, a commonly used oral medication for ITP, which was intended to be tapered off during the trial.
The primary measure of success was “time to treatment failure,” which included indicators such as low platelet counts, the requirement for additional therapy, or death. Results showed an estimated probability of avoiding treatment failure at 12 months was 54.2% in the high-dose group and 50.5% in the low-dose group, compared to only 30% in the placebo group. Furthermore, at the six-month mark, 62% of patients in the high-dose group maintained stable platelet counts, in contrast to 39.2% in the placebo group.
Future Implications and Ongoing Research
Further clinical trials for ianalumab are currently underway, exploring its potential in treating other autoimmune conditions. The antibody is not yet approved by the FDA for patient use, but researchers intend to monitor the long-term responses of participants involved in the study.
Dr. Cuker expressed optimism about the findings, stating, “Improving the long-term reality of living with ITP is not something we’ve been able to think about before. The goal has always been to improve platelet counts or reduce the risk of bleeding, but this research is ushering in a new era of hope for patients with ITP.”
The study received funding from Novartis, highlighting the ongoing collaboration between academia and the pharmaceutical industry in advancing treatment options for complex medical conditions.
