The efficacy of omalizumab in Cutaneous Mastocytosis: A case series

Abstract

Background: Mastocytosis describes a heterogeneous group of disorders arising from a clonal proliferation of mast cells. Given the lack of curative treatments for the cutaneous form, there is a significant need for superior therapies. Omalizumab is a recombinant DNA‐derived humanized IgG monoclonal antibody that selectively binds to human immunoglobulin E (IgE). It represents a potential treatment for the management of cutaneous mastocytosis, which currently has no standard treatment. Methods: Two patients were treated with subcutaneous omalizumab 300 mg every 4 weeks. Discussion: Patient 1 experienced 50% reduction in cutaneous infiltration and moderate improvement in pruritus. Patient 2 underwent 90% complete clearance of cutaneous lesions and reported full resolution of pruritus. The median duration of treatment was 24 weeks and time to response was 8 weeks. No significant changes in tryptase levels were observed. Both patients experienced injection site reactions. Conclusion: We provide evidence from two cases supporting the efficacy of IgE‐mediated therapy in the treatment of cutaneous mastocytosis. Even at a higher‐than‐standard dose (300 mg vs. 150 mg), the drug was well‐tolerated. As we await the results of pivotal clinical trials, omalizumab appears to be a promising treatment option in patients with cutaneous mastocytosis unresponsive to traditional therapies.

Mediator-Related Symptoms and Anaphylaxis in Children with Mastocytosis

“…Recently, omalizumab has been proposed for mastocytosis patients to treat severe mediator-related symptoms and to prevent anaphylaxis (3,(91)(92)(93)(94)(95)(96)(97)(98)(99)(100)(101). The drug was indeed found to be effective in the prevention of recurrent episodes of idiopathic anaphylaxis in adults with mastocytosis (91)(92)(93)(94)(95)(96)(97)(98)(99)(100)(101), but has only be licensed for use in children over 12 years of age. The results of the XOLMA study has shown that omalizumab was safe and improved mastocytosis symptoms like diarrhea, dizziness, flush and anaphylactic reactions (100).…”

“…First long-term follow-ups are available with improvement of clinical symptoms in two patients with SM and recurrent anaphylaxis over an observation period of 12 years (99). Several case reports have suggested the usefulness of omalizumab in SM (92) and CM in adults (93), but also in adolescents (94), and children (95). Although the evidence is based only on uncontrolled observations in a small number of patients, this drug is likely to be effective in the prevention of recurrent anaphylaxis in children with or without mastocytosis (97).…”

Omalizumab in the treatment of adult patients with mastocytosis: A systematic review

“…The efficacy of treatment with Omalizumab on different symptoms is summarized in Figure 2 and Table 2 …”

Role of Mast Cells in the Pathogenesis of Pruritus in Mastocytosis

“…There is emerging evidence that IL-31 plays a role in pruritus in patients with mastocytosis, suggesting that nemolizumab, a potent anti-IL-31 mono clonal antibody, has the potential to be effective in this group of patients, albeit this suggestion needs to be confirmed in clinical settings (102). Another treatment option for pruritus unresponsive to traditional therapies with antihistamines could be omalizumab, the anti-IgE monoclonal antibody, which might block mast cell activity (103). Interestingly, the NK-1 inhibitor, aprepitant, developed for the prevention of chemotherapy-induced nausea and vomiting, seemed to possess some antipruritic properties, as well as some other NK-1 inhibitors (serlopitant and tradipitant) might also provide some benefit in the treatment of pruritus (104)(105)(106).…”