A combination of bortezomib and rituximab yields a dramatic response in a woman with highly refractory immune thrombocytopenic purpura: a case report

Current therapeutic strategies and perspectives in refractory ITP: What have we learned recently?

Immune thrombocytopenia (ITP) is an acquired autoimmune bleeding disorder featured by increased platelet destruction and deficient megakaryocyte maturation. First-line treatments include corticosteroids, intravenous immunoglobulin and intravenous anti-D immunoglobulin. Second-line treatments consist of rituximab, thrombopoietin receptor agonists and splenectomy. Although most patients benefit from these treatments, an individualized treatment approach is warranted due to the large heterogeneity among ITP patients. In addition, ITP patients may relapse and there remains a subset of patients who become refractory to treatments. The management of these refractory patients is still a challenge. This review aims to summarize emerging therapeutic approaches for refractory ITP in several categories according to their different targets, including macrophages, platelets/megakaryocytes, T cells, B cells, and endothelial cells. Moreover, current management strategies and combination regimens of refractory ITP are also discussed.

Bortezomib: a proteasome inhibitor for the treatment of autoimmune diseases

Autoimmune diseases (ADs) are conditions in which the immune system cannot distinguish self from non-self and, as a result, tissue injury occurs primarily due to the action of various inflammatory mediators. Different immunosuppressive agents are used for the treatment of patients with ADs, but some clinical cases develop resistance to currently available therapies. The proteasome inhibitor bortezomib (BTZ) is an approved agent for first-line therapy of people with multiple myeloma. BTZ has been shown to improve the symptoms of different ADs in animal models and ameliorated symptoms in patients with systemic lupus erythematous, rheumatoid arthritis, myasthenia gravis, neuromyelitis optica spectrum disorder, Chronic inflammatory demyelinating polyneuropathy, and autoimmune hematologic diseases that were nonresponsive to conventional therapies. Proteasome inhibition provides a potent strategy for treating ADs. BTZ represents a proteasome inhibitor that can potentially be used to treat AD patients resistant to conventional therapies.

Bortezomib treatment for refractory nontuberculous mycobacterial infection in the setting of interferon gamma autoantibodies

Interferon-γ autoantibodies increase the risk of disseminated nontuberculous mycobacterial infections. Addition of rituximab to antibiotics accelerates and improves outcomes, but refractory infections can occur due to persistent production of autoantibodies. We combined bortezomib with rituximab to reduce autoantibodies leading to clinical and radiographic improvement in infection.

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IFNγ autoantibodies increase the risk of disseminated infections with intracellular pathogens.

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Rituximab combined with antibiotics improves outcomes, but infections can become refractory.

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The addition of bortezomib is safe with close monitoring and can improve clinical outcomes.

Evolving treatment modalities for immune thrombocytopenia in adults

The management of patients with relapsed or refractory immune thrombocytopenia (ITP) remains challenging for hematologists. While there are a multitude of drugs available, it is largely an individualized management based on patient preferences, side effects, previous treatment received, and responses to them, comorbidities and cost associated with the treatment. We hereby review the newer approaches in the treatment of ITP.

Bortezomib-based antibody depletion for refractory autoimmune hematological diseases

Certain patients with antibody-mediated autoimmune disease exhibit poor responses to conventional immunosuppression, including B-cell depletion with rituximab. Proteasome inhibitors such as bortezomib demonstrate pleiotropic immunomodulatory effects, including direct toxicity to antibody-producing cells. Here, we report preliminary evidence for the efficacy of bortezomib as salvage therapy for refractory autoimmune hematological disease. Thirteen treatment episodes in 10 patients with autoimmune hematological phenomena (autoimmune hemolytic anemia [AIHA; n = 8], acquired hemophilia (n = 1), immune thrombocytopenia (n = 1), and thrombotic thrombocytopenic purpura [TTP; n = 3]) and a median of 5 (range, 3-12) prior lines of therapy demonstrated an overall response rate of 77% (10 of 13) including 38% (5 of 13) complete remissions. The majority of clinical improvements were rapid, correlated with biomarkers of autoantibody reduction, and were associated with an acceptable safety profile. Responses appeared durable following treatment of TTP and acquired hemophilia; AIHA responses were more limited with a pattern of relapse following bortezomib cessation. These data provide proof of concept for the utility of proteasome inhibition as antibody depletion therapy in autoimmune disease.