Ianalumab Shows Promise for Patients with Immune Thrombocytopenia

A recent clinical trial has demonstrated that the investigational drug ianalumab, when combined with standard therapy, significantly extends the time to treatment failure for patients suffering from immune thrombocytopenia (ITP). This condition, characterized by a low platelet count due to the immune system mistakenly attacking platelets, affects approximately 50,000 individuals in the United States, with women being more frequently impacted than men.

The findings were presented at the 67th American Society of Hematology (ASH) Annual Meeting and published in the journal Blood. The study represents the first examination of a novel drug for ITP early in the disease course. According to lead author Hanny Al-Samkari, MD, who holds the Peggy S. Blitz Endowed Chair in Hematology/Oncology at Mass General Brigham Cancer Institute and is an associate professor of medicine at Harvard Medical School, the treatment yielded promising results in terms of long-term disease control.

In the trial, patients who received four once-monthly infusions of ianalumab alongside standard therapy experienced a longer duration without bleeding episodes that required urgent treatment compared to those administered a placebo. The study enrolled 152 patients with ITP who had either not responded to or relapsed after standard first-line therapy, with about two-thirds of participants being women. All patients had a baseline platelet count of less than 30,000 per microliter of blood.

Eltrombopag, a medication that stimulates platelet production, was also given to all participants for a period of 16 to 24 weeks. Patients were randomised to receive either a lower dose of ianalumab (3 mg/kg), a higher dose (9 mg/kg), or a placebo. The primary endpoint of the study was defined as the time to treatment failure, which was determined by the occurrence of bleeding episodes requiring rescue therapy or the initiation of new ITP treatment after discontinuing study therapy.

The results showed that patients receiving the higher dose of ianalumab had a median time to treatment failure of 13 months, while those on the placebo experienced treatment failure in just 4.7 months. For the lower-dose group, the time to treatment failure was deemed “not estimable,” indicating that too few patients experienced significant bleeding episodes to calculate a median time.

At the six-month mark, approximately 62% of patients on the higher dose and 56.9% of those on the lower dose achieved a stable response, meaning their platelet counts remained above 50,000 without the need for rescue therapy. In contrast, only 39.2% of the placebo group reached this benchmark.

Additionally, patients receiving ianalumab reported improved quality of life, noting reduced fatigue levels, a common symptom of ITP. Despite the benefits, those treated with ianalumab experienced higher rates of transient neutropenia, a temporary decrease in white blood cells, though this condition resolved quickly and did not lead to a higher incidence of infections compared to the placebo group.

The study highlights a significant unmet need for effective therapies in ITP, particularly as long-term steroid use can result in adverse side effects such as obesity and osteoporosis. Dr. Al-Samkari stated, “The longer people have ITP, the more difficult it becomes to treat. One of the major unmet needs in ITP treatment is a therapy that truly changes the course of the disease.”

While promising, the study did have limitations. Patients had received only one prior treatment for ITP, leaving questions about the effectiveness of ianalumab for individuals with more extensive treatment histories. Furthermore, the follow-up period was not yet sufficiently long to determine whether ianalumab can halt long-term disease progression. Dr. Al-Samkari noted that patients will be followed for an extended period of 39 months to assess the long-term durability of the treatment.

Another trial, known as VAYHIT1, is currently underway to evaluate the efficacy of ianalumab combined with steroids in previously untreated ITP patients. This study aims to shed further light on the potential of ianalumab as a transformative therapy in the management of ITP.

The findings from the VAYHIT2 trial underscore a significant advancement in the treatment landscape for patients with immune thrombocytopenia, offering hope for better disease management and quality of life for those affected.