Positive Phase 2 Results Reported at ASH For MAB for ITP

Rozanolixizumab touted as possible alternative to standard therapy of corticosteroids, intravenous immunoglobulin

UCB has announced positive results from a phase 2 study of its novel, first-in-class subcutaneous monoclonal antibody, rozanolixizumab, in patients with primary immune thrombocytopenia (ITP). The data were presented during an oral presentation at the 61st American Society of Hematology Annual Meeting & Exposition in Orlando, Florida.

Primary ITP is an acquired autoimmune disorder characterized, in most cases, by the presence of pathogenic IgG autoantibodies, which target platelets and megakaryocytes, leading to the removal and destruction of both circulating and newly formed platelets, ultimately resulting in a propensity for bleeding.

Individuals living with ITP experience unpredictable and debilitating symptoms, including spontaneous bruising, bleeding and fatigue, that can greatly impact their activities of daily life. Additionally, the limited current treatment options for people with ITP can be time-consuming and invasive.

The standard of care for patients with newly diagnosed ITP consists of corticosteroids or intravenous immunoglobulin. Patients intolerant to corticosteroids or with contraindications are treated with IVIg or anti-D (where appropriate), either alone or in combination. Subsequent treatments include immunosuppressive agents (e.g., azathioprine and mycophenolate mofetil), rituximab, TPO receptor agonists (e.g., eltrombopag and romiplostim) or splenectomy. 

Rozanolixizumab is an anti-neonatal Fc receptor (FcRn) therapy. It’s a subcutaneously administered, humanized monoclonal antibody designed to block the interaction of FcRn and IgG, inhibiting IgG recycling and inducing the removal of pathogenic IgG autoantibodies. 

In the phase 2 study, 66 patients received either a single dose or multiple doses of rozanolixizumab. The total weekly dose was similar in all treatment groups, ranging from 15 to 21 mg/kg. Clinically relevant improvements in platelet count and decreases in immunoglobin G levels were observed across all dose groups, with higher response rate and shorter time to response achieved by the 1 x 15 mg/kg and 1 x 20 mg/kg rozanolixizumab dose groups, compared with patients in the multiple-dose cohorts.

Rozanolixizumab was well tolerated across all dose groups, consistent with previous rozanolixizumab studies. The most commonly reported adverse event was headache, with mild-to-moderate headaches seen at higher doses; other reported adverse events included diarrhea and vomiting. These events were usually of short duration and the majority of events resolved without treatment. No patient discontinued the study due to side effects.

Source: UCB, Dec. 9, 2019