Daratumumab for autoimmune diseases: a systematic review

Targeting CD38 in Antibody-Mediated Rejection

Antibody-mediated rejection (AMR) remains a major challenge in clinical transplantation. Current therapies have yielded inconsistent outcomes, highlighting the need for innovative approaches. CD38, a multifunctional glycoprotein, is highly expressed on plasma cells and natural killer (NK) cells, potentially offering a dual mechanism of action that could intervene in the pathophysiologic course of AMR: depleting alloantibody-producing plasma cells and NK cells. This review focuses on recent results from CD38-targeted therapies, with felzartamab emerging as a promising option. Previous case reports and series suggested that off-label daratumumab treatment could effectively reverse AMR. Felzartamab has now demonstrated safety and efficacy in a phase 2 trial for late AMR. Reductions in microvascular inflammation, downregulation of rejection-associated transcripts, and decreases in donor-derived cell-free DNA paralleled a substantial decrease in NK cell counts. However, felzartamab did not significantly affect donor-specific antibodies, which may reflect its distinct mechanism of action, primarily involving antibody-dependent cellular cytotoxicity and phagocytosis. The effects on rejection activity may have a rapid onset, but are transient. The potential benefits of prolonged therapy are currently being investigated in a recently launched phase III trial. Future studies may expand the applications of CD38 targeting to early AMR or broader indications, such as DSA-negative microvascular inflammation.

Immunotherapy for autoimmune encephalitis

Autoimmune encephalitis (AE) is increasingly recognized as a cause of brain disorders that greatly benefit from immunotherapy. Starting treatment quickly and increasing the use of immunotherapy can lead to better results for AE patients. Currently, there are standardized treatment guidelines for treating AE. First-line therapy includes intravenous corticosteroids, plasma exchange, and intravenous immunoglobulin. Second-line therapy involves rituximab, cyclophosphamide, mycophenolate mofetil, and azathioprine. Third-line therapy uses agents that deplete plasma cells (bortezomib, daratumumab, and obinutuzumab), drugs that modulate cytokines (tocilizumab, anakinra, tofacitinib, and interleukin-2), and treatments that target intrathecal immune cells (intrathecal methotrexate). This review aims to summarize the immunotherapeutic strategies available for treating AE and provide an update on refractory AE.

BCMA CAR T cells in a patient with relapsing idiopathic inflammatory myositis after initial and repeat therapy with CD19 CAR T cells

CD19 chimeric antigen receptor (CD19 CAR) T cell therapy has been shown to induce stable drug-free remission in patients with refractory autoimmune disease. The management of potential relapses is currently unclear. Here we report on a 45-year-old woman with treatment-refractory Jo-1-associated anti-synthetase syndrome, who initially achieved disease remission after CD19 CAR T cell therapy but then experienced disease relapse after 9 months. After reinfusion of the same product, CAR T cells failed to expand and T cells targeting the CD19 CAR were detected. Despite full-dose lymphodepletion, no clinical response was observed. After bridging with anti-CD38 antibody daratumumab, which was efficacious with limited durability, plasma-cell-targeting B-cell maturation antigen (BCMA) CAR T cell therapy was performed. BCMA CAR T cells expanded, cleared plasma cells in lymphoid tissue, reduced autoantibody levels and re-induced stable drug-free remission. This case highlights the challenges in CAR T cell reinfusion, the potential of alternative targets and products, and suggests that the depletion of plasma cells may enhance therapeutic outcomes in patients who become treatment-refractory.

Advances in the treatment of neuromyelitis optic spectrum disorder

Neuromyelitis optic spectrum disorder (NMOSD) is a rare autoimmune disease characterized by recurrent episodes and severe debilitation. It primarily involves the central nervous system and is associated with the presence of aquaporin-4 antibodies. Effective management of NMOSD necessitates long-term therapeutic strategies that focus on alleviating symptoms during acute episodes and preventing relapse. In recent years, the approval of emerging biologics targeting B cells, interleukin-6 receptors, and the complement pathway has marked a transformative development in NMOSD treatment. This article provides a comprehensive review of therapeutic advances in NMOSD, integrating the current literature to serve as a theoretical basis for clinical decision-making of NMOSD patients.

Advances in maintenance therapies for neuromyelitis optica spectrum disorders: A new era of targeted drugs

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is a rare inflammatory demyelinating disease of the central nervous system, mainly affecting the optic nerve and spinal cord, with a high rate of recurrence and disability. The spectrum of possibilities for NMOSD maintenance therapies has increased recently due to the development of novel medications based on a deeper understanding of its pathogenesis.

METHODS

Clinical and preclinical advances in NMOSD maintenance therapies were searched in PubMed up until July 20, 2024.

RESULTS

We reviewed the treatment options including approved monoclonal antibodies, clinical trial drugs, and preclinical targets. Both randomized clinical trials and real-word studies have evaluated the safety and efficacy of monoclonal antibodies against complement, IL-6 receptor and B cells. Drugs in the early stage of clinical trials are mainly focused on small molecule targeted drugs and cell-based therapies. Additionally, preclinical studies aimed to explore new targets, such as aquaporin blocking antibodies, based on experiences in cell cultures and animal models.

CONCLUSIONS

From biologics to small molecules and cells, researchers have endeavored to provide better medical care for NMOSD patients. With the emergence of more and more targeted drugs, it is anticipated that the treatment of NMOSD will enter a new era.

Opportunities and limitations of B cell depletion approaches in SLE

B cell depletion with rituximab, a chimeric monoclonal antibody that selectively targets B cells by binding CD20, has been used off label in severe and resistant systemic lupus erythematosus (SLE) for over two decades. Several biological mechanisms limit the efficacy of rituximab, including immunological reactions towards the chimeric molecule, increased numbers of residual B cells, including plasmablasts and plasma cells, and a post-treatment surge in B cell-activating factor (BAFF) levels. Consequently, rituximab induces remission in only a proportion of patients, and safety issues limit its use. However, the use of rituximab has established the value of B cell depletion strategies in SLE and has guided the development of several improved B cell depletion therapies for SLE. These include enhanced monoclonal antibodies, modalities that redirect the specificity of patient T cells using chimeric antigen receptor T cells or bispecific T cell engagers, and combination treatment that simultaneously inhibits the BAFF pathway. In this Review, we consider evidence gathered from over two decades of using rituximab in SLE and examine how B cell depletion therapies could be further optimized to achieve immunological and clinical efficacy. In addition, we discuss the prospects of B cell depletion strategies for personalized treatment in SLE based on genetic research and studies in pre-symptomatic individuals.

CD38 monoclonal antibody felzartamab for late antibody-mediated rejection: a phase II drug evaluation

INTRODUCTION

Felzartamab is a novel, fully human CD38 monoclonal antibody, currently in development for the treatment of antibody-mediated rejection (AMR) following kidney transplantation.

AREAS COVERED

This review focuses on current phase II trials of felzartamab in AMR and other immune-mediated kidney diseases. Specifically, it discusses the drug's mechanism of action, current phase of clinical development, potential future applications and regulatory status.

EXPERT OPINION

CD38 is an activation marker expressed on the surface of plasma cells and immune cells, including natural killer cells (NK cells) cells. In a recent phase II randomized, placebo-controlled clinical trial, felzartamab demonstrated an acceptable safety and side-effect profile in patients with AMR after kidney transplantation. Efficacy outcomes suggested potential therapeutic benefits, including significant reductions in morphologic and molecular AMR activity. Given the mixed results of previous clinical trials for AMR treatments, the novel approach of targeting both antibody-secreting plasma cells and innate effector cells such as CD38+ NK cells may offer a promising new therapeutic strategy. Felzartamab is also being investigated for the treatment of other antibody-mediated kidney diseases, such as lupus nephritis, primary membranous nephropathy and IgA nephropathy. If proven effective, it could expand the therapeutic options for kidney transplant rejection and primary kidney diseases.

Novel therapies in CIDP

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a heterogeneous but clinically well-described disease within circumscribed parameters. It is immunologically mediated through several poorly understood mechanisms. First-line therapies with steroids, intravenous immunoglobulin (IVIG) or plasma exchange are each effective in about two-thirds of patients. These treatments are seldom associated with complete resolution or cure, and often pose considerable practical, financial and medical implications.Our understanding of many of the key pathological processes in autoimmune diseases is expanding, and novel targeted therapeutics are being developed with promise in several autoimmune neurological disorders.This narrative review looks first at detailing key pathogenic mechanisms of disease in CIDP, followed by an in-depth description of potential novel therapies and the current evidence of their application in clinical practice.

Efficacy and safety of daratumumab in multiresistant immune-mediated thrombotic thrombocytopenic purpura

The immunosuppressive treatment of immune-mediated thrombotic thrombocytopenic purpura (iTTP) in patients with intolerance or refractoriness to the B-cell depleting monoclonal antibody rituximab remains debated. Daratumumab, a plasma cell-directed monoclonal antibody targeting CD38, represents a therapeutic option, but data are scarce. The French Thrombotic Microangiopathies Reference Center conducted a nationwide survey on iTTP patients treated with daratumumab. Nine episodes from seven patients were identified. Treatment was administered for A Disintegrin And Metalloproteinase with ThromboSpondin-1 motifs, 13th member (ADAMTS13) relapses while patients were otherwise in clinical response (N = 8), or during the acute phase of the disease following rituximab intolerance (N = 1). Patients have received a median of three previous therapeutic lines. ADAMTS13 activity improved in eight cases following daratumumab administration, including three cases where ADAMTS13 normalized. ADAMTS13 relapses occurred in three patients; in two cases, retreatment with daratumumab was successful. Median ADAMTS13 relapse-free survival was not reached; 12-month ADAMTS13 relapse-free survival was 56%. Daratumumab-related adverse events occurred in five cases and were non-severe infusion-related reactions in all cases. These results suggest that daratumumab may be an effective treatment option for iTTP patients with intolerance or refractoriness to rituximab.

Where are we now in biologic drugs for myositis?

Idiopathic inflammatory myopathies (IIMs) are a rare and heterogeneous group of chronic autoimmune disorders. Up to 40% of IIM patients have long-term sequelae and significant functional disability. Its management can be challenging and new therapies are badly needed. The small number of cases with diverse presentations and different diagnostic criteria significantly affect clinical trial results. Only IVIG has been internationally approved for IIM patients. Most clinical trials of new biologic therapies have failed to meet their primary endpoints in IIM, with only one biologic drug recommended for refractory IIM treatment (rituximab), although not approved. We review several new emerging biologic drugs, including B cell depletion therapies, abatacept, Janus kinase inhibitors, and aldesleukin. Encouragingly, some phase II randomized controlled trials have evaluated the efficacy and safety of new biologics in IIM, demonstrating an improvement in clinical and laboratory measures.

Systemic lupus erythematosus: pathogenesis and targeted therapy

Systemic lupus erythematosus (SLE) is a multifaceted autoimmune disorder characterized by dysregulated immune responses and autoantibody production, which affects multiple organs and varies in clinical presentation and disease severity. The development of SLE is intricate, encompassing dysregulation within the immune system, a collapse of immunological tolerance, genetic susceptibilities to the disease, and a variety of environmental factors that can act as triggers. This review provides a comprehensive discussion of the pathogenesis and treatment strategies of SLE and focuses on the progress and status of traditional and emerging treatment strategies for SLE. Traditional treatment strategies for SLE have mainly employed non-specific approaches, including cytotoxic and immunosuppressive drugs, antimalarials, glucocorticoids, and NSAIDs. These strategies are effective in mitigating the effects of the disease, but they are not a complete cure and are often accompanied by adverse reactions. Emerging targeted therapeutic drugs, on the other hand, aim to control and treat SLE by targeting B and T cells, inhibiting their activation and function, as well as the abnormal activation of the immune system. A deeper understanding of the pathogenesis of SLE and the exploration of new targeted treatment strategies are essential to advance the treatment of this complex autoimmune disease.

Bortezomib Led to Remission of Immune Thrombocytopenic Purpura in a Patient with Smoldering Multiple Myeloma

A 79-year-old man with smoldering multiple myeloma (MM) developed sudden severe thrombocytopenia and active bleeding. Since anti-GPIIb/IIIa autoantibodies were detected on the platelet surface, thrombocytopenia due to an autoimmune etiology was diagnosed. Although neither steroids nor intravenous immunoglobulins provided improvement, bortezomib provided rapid normalization of the platelet counts with disappearance of the anti-GPIIb/IIIb autoantibodies. MM is rarely associated with immune thrombocytopenic purpura (ITP). Although the underlying pathogenesis of MM and ITP remains elusive, anti-myeloma drugs might be beneficial.

Acute leukoencephalopathy associated with daratumumab treatment in POEMS syndrome: a case report

Objectives

Daratumumab, a monoclonal antibody against CD38, is increasingly used in the treatment of multiple myeloma, other hematological malignancies and autoimmune diseases. Little is known about its CNS toxicity. We present a case of a patient with POEMS syndrome (syndrome of polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy and skin changes) who developed an acute leukoencephalopathy shortly after initiation of therapy with daratumumab.

Methods

Case report following the CARE case report guidelines.

Results

The patient presented with symptoms of headache and diffuse worsening of a pre-existing tetraparesis. MRI showed a rapidly progressive leukoencephalopathy. Extensive diagnostic evaluation revealed no specific cause, suggesting the leukoencephalopathy to be caused by daratumumab.

Discussion

Our report highlights a probably rare, but clinically significant adverse effect of daratumumab and underlines the necessity of raised vigilance for neurological side effects in patients treated with daratumumab.

The Future of CAR T Therapeutics to Treat Autoimmune Disorders

The concept of chimeric antigen receptor (CAR) T cell therapy emerged from cancer immunotherapy and has been rapidly adapted and developed for the treatment of autoimmune, especially B-cell-driven, diseases since the first publication of an article featuring a patient with systemic lupus erythematosus in 2021. Phase II studies are about to start, but up to now, only case reports and small series have been published. In contrast to hemato-oncological diseases, where an aggressive response to malignant cells and long-lasting persistence of CAR T cells has been aimed at and observed in many patients, this is not the case with autoimmune diseases but might not be necessary to control disease. Future studies will focus on the optimal target but also on the optimal level of immunogenicity. The latter can be influenced by numerous modulations that affect not only cytokine release but also regulation. In addition, there are potential applications in regulatory cells such as CAR regulatory T cells (Treg). The question of toxicity reduction must also be addressed, as long-term complications such as the potential development of malignant diseases, infections, or cytopenia must be considered even more critically in the area of autoimmune diseases than is the case for patients with oncologic diseases. Alternative antibody-based therapies using the same target (e.g., CD3/CD19 bispecific targeting antibodies) have not been used in these patients and might also be considered in the future. In conclusion, CAR T cell therapy represents a promising therapeutic approach for autoimmune diseases, offering a targeted strategy to modulate immune responses and restore immune tolerance.

Diagnosis of light‑chain deposition disease after renal transplantation: A case report and literature review

Light chain deposition disease (LCDD) is a rare, clonal plasma cell proliferative condition. The deposition of nonamyloid monoclonal immunoglobulin light chains predominantly affects the kidneys, which may lead to end-stage renal disease, eventually requiring renal replacement therapy. The present study reported a rare case of LCDD that was confirmed after renal transplantation. A 49-year-old man initially presented with heavy proteinuria, hypoproteinemia, hyperlipidemia and renal insufficiency. The patient was diagnosed with nephrotic syndrome and pathological examination revealed fibrillary glomerulonephritis in 2014. Treatment was started with prednisolone. About 5 years later, the patient began to receive continuous hemodialysis due to worsening serum creatinine levels. Renal allograft transplantation was performed in 2020 and dialysis independence was achieved. Laboratory findings before renal transplantation revealed that serum and urine immunofixation electrophoresis was negative. Allograft kidney biopsy established the pathological diagnosis of LCDD at >1 year after renal transplantation for renal dysfunction. The treatment is challenging due to the lack of generally accepted standard treatment practices. Administration of bortezomib combined with dexamethasone was started. As anemia and renal failure developed progressively, the treatment was switched to anti-CD38 antibody and continuous hemodialysis was restarted. The best response achieved was hematological partial response and relief of anemia. However, the patient's renal function did not improve and he remains to have end-stage kidney disease. LCDD is easily missed in cases in which serum and urine immunofixation electrophoresis is negative. Hence, early recognition of LCCD based on kidney biopsy is important. To the best of our knowledge, the use of anti-CD38 antibody therapy in patients with LCDD is rarely reported. Anti-CD38 antibody is effective in treating LCDD, but it may not reverse the marked deterioration of renal function.

A Randomized Phase 2 Trial of Felzartamab in Antibody-Mediated Rejection

BACKGROUND

Antibody-mediated rejection is a leading cause of kidney-transplant failure. The targeting of CD38 to inhibit graft injury caused by alloantibodies and natural killer (NK) cells may be a therapeutic option.

METHODS

In this phase 2, double-blind, randomized, placebo-controlled trial, we assigned patients with antibody-mediated rejection that had occurred at least 180 days after transplantation to receive nine infusions of the CD38 monoclonal antibody felzartamab (at a dose of 16 mg per kilogram of body weight) or placebo for 6 months, followed by a 6-month observation period. The primary outcome was the safety and side-effect profile of felzartamab. Key secondary outcomes were renal-biopsy results at 24 and 52 weeks, donor-specific antibody levels, peripheral NK-cell counts, and donor-derived cell-free DNA levels.

RESULTS

A total of 22 patients underwent randomization (11 to receive felzartamab and 11 to receive placebo). The median time from transplantation until trial inclusion was 9 years. Mild or moderate infusion reactions occurred in 8 patients in the felzartamab group. Serious adverse events occurred in 1 patient in the felzartamab group and in 4 patients in the placebo group; graft loss occurred in 1 patient in the placebo group. At week 24, resolution of morphologic antibody-mediated rejection was more frequent with felzartamab (in 9 of 11 patients [82%]) than with placebo (in 2 of 10 patients [20%]), for a difference of 62 percentage points (95% confidence interval [CI], 19 to 100) and a risk ratio of 0.23 (95% confidence interval [CI], 0.06 to 0.83). The median microvascular inflammation score was lower in the felzartamab group than in the placebo group (0 vs. 2.5), for a mean difference of -1.95 (95% CI, -2.97 to -0.92). Also lower was a molecular score reflecting the probability of antibody-mediated rejection (0.17 vs. 0.77) and the level of donor-derived cell-free DNA (0.31% vs. 0.82%). At week 52, the recurrence of antibody-mediated rejection was reported in 3 of 9 patients who had a response to felzartamab, with an increase in molecular activity and biomarker levels toward baseline levels.

CONCLUSIONS

Felzartamab had acceptable safety and side-effect profiles in patients with antibody-mediated rejection. (Funded by MorphoSys and Human Immunology Biosciences; ClinicalTrials.gov number, NCT05021484; and EUDRACT number, 2021-000545-40.).

Moving towards a new era for the treatment of neuromyelitis optica spectrum disorders

Neuromyelitis optica spectrum disorders (NMOSD) include a rare group of autoimmune conditions that primarily affect the central nervous system. They are characterized by inflammation and damage to the optic nerves, brain and spinal cord, leading to severe vision impairment, locomotor disability and sphynteric disturbances. In the majority of cases, NMOSD arises due to specific serum immunoglobulin G (IgG) autoantibodies targeting aquaporin 4 (AQP4-IgG), which is the most prevalent water-channel protein of the central nervous system. Early diagnosis and treatment are crucial to manage symptoms and prevent long-term disability in NMOSD patients. NMOSD were previously associated with a poor prognosis. However, recently, a number of randomized controlled trials have demonstrated that biological therapies acting on key elements of NMOSD pathogenesis, such as B cells, interleukin-6 (IL-6) pathway, and complement, have impressive efficacy in preventing the occurrence of clinical relapses. The approval of the initial drugs marks a revolutionary advancement in the treatment of NMOSD patients, significantly transforming therapeutic options and positively impacting their prognosis. In this review, we will provide an updated overview of the key immunopathological, clinical, laboratory, and neuroimaging aspects of NMOSD. Additionally, we will critically examine the latest advancements in NMOSD treatment approaches. Lastly, we will discuss key aspects regarding optimization of treatment strategies and their monitoring.

Mezagitamab in systemic lupus erythematosus: clinical and mechanistic findings of CD38 inhibition in an autoimmune disease

OBJECTIVE

To evaluate safety and mechanism of action of mezagitamab (TAK-079), an anti-CD38 monoclonal antibody, in patients with moderate to severe systemic lupus erythematosus (SLE).

METHODS

A phase 1b double-blind, placebo-controlled, multicentre study was conducted in patients with SLE receiving standard background therapy. Eligible patients were adults who met the 2012 SLICC or ACR criteria for diagnosis, had a baseline SLE Disease Activity Index 2000 (SLEDAI-2K) score of ≥6 and were positive for anti-double-stranded DNA antibodies and/or anti-extractable nuclear antigens antibodies. Patients received 45 mg, 90 mg or 135 mg of mezagitamab or placebo every 3 weeks over 12 weeks. Primary endpoints were safety and tolerability. Secondary endpoints included pharmacokinetics and pharmacodynamics. Exploratory assessments included disease activity scales, deep immune profiling and interferon pathway analysis.

RESULTS

22 patients received at least one dose of either mezagitamab or placebo. In patients exposed to mezagitamab (n=17), drug was well tolerated. Adverse event (AEs) were balanced across treatment groups, with no treatment emergent AEs exceeding grade 2. Responder analyses for Cutaneous Lupus Erythematosus Disease Area and Severity Index (CLASI) and SLEDAI-2K did not reveal any observable differences across treatment groups. However, there was a trend for more profound skin responses among patients with higher CLASI scores (>10) at baseline. Pharmacodynamic analysis showed median CD38 receptor occupancy up to 88.4% on CD38+ natural killer cells with concurrent depletion of these cells up to 90% in the 135 mg group. Mean reductions in IgG and autoantibodies were less than 20% in all dose groups. Cytometry by time of flight and type 1 interferon gene analysis revealed unique fingerprints that are indicative of a broad immune landscape shift following CD38 targeting.

CONCLUSIONS

Mezagitamab had a favourable safety profile in patients with moderate to severe SLE and elicited a pharmacodynamic effect consistent with CD38+ cell depletion. These findings reveal novel insights into the drug's mechanism of action and support the continued investigation of mezagitamab in autoimmune diseases.