"Plasma exchange in a bottle": An overview of efgartigimod for apheresis practitioners

2025 update on clinical trials in immune thrombocytopenia

Although the development and regulatory approval of the thrombopoietin receptor agonists revolutionized aspects of the immune thrombocytopenia (ITP) treatment landscape over the past two decades, there remain many areas of high unmet need. Therefore, a number of investigational and repurposed agents are currently undergoing clinical development in ITP. In a departure from historical trials, which largely focused on the indefinite treatment of persistent or chronic ITP, ongoing trials run the gamut of disease phases, and include novel agents being evaluated in early phases of the disease to attempt to modify the disease course. Many agents in development target disease pathophysiologic mechanisms not previously targeted by agents in current use, including platelet autoantibody recycling, B-cell maturation and differentiation, long-lived plasma cells, and the complement system, among others. These agents represent promising treatment options for patients with otherwise refractory disease or who are intolerant of currently available therapies. Additionally, with our increasing understanding of the diverse immune mechanisms at play in ITP, the expansion of the therapeutic armamentarium to include agents targeting diverse pathophysiologic mechanisms may allow a more personalized therapeutic selection in the future. This manuscript provides an up-to-date, in-depth overview of recently completed and ongoing clinical trials in ITP.

Successful treatment with efgartigimod as an add-on therapy in acute attack of anti-AQP4 antibody-positive NMOSD: a case report

BACKGROUND

Neuromyelitis Optica Spectrum Disorder (NMOSD) is an autoimmune demyelinating disease characterized by recurrent myelitis and optic neuritis. It is associated with high rates of relapse and disability. The main treatment strategies for acute attacks include intravenous methylprednisolone pulse (IVMP) treatment and rescue treatment with plasma exchange (PLEX). Recently, the blockade of neonatal Fc receptor (FcRn)-IgG interaction has gained momentum as a therapeutic strategy. Efgartigimod, the first approved FcRn inhibitor for treating generalized myasthenia gravis, has shown impressive safety, efficacy, and tolerability, and is being regarded as "PLEX in a bottle".

CASE DESCRIPTION

We report a 65-year-old female patient who was diagnosed with anti-AQP4 antibody positive NMOSD. Add-on treatment with efgartigimod to IVMP and intravenous immunoglobulin (IVIG) at the second acute relapse showed favorable results.

CONCLUSION

This case suggests that efgartigimod is a potentially effective add-on therapy in acute attacks of AQP4-IgG-positive NMOSD.

Efgartigimod in generalized myasthenia gravis: A real-life experience at a national reference center

BACKGROUND AND PURPOSE

Inhibition of the neonatal Fc receptor (FcRn) for IgG is a promising new therapeutic strategy for antibody-mediated disorders. We report our real-life experience with efgartigimod (EFG) in 19 patients with generalized myasthenia gravis (gMG) along a clinical follow-up of 14 months.

METHODS

EFG was administered according to the GENERATIVE protocol (consisting of a Fixed period of two treatment cycles [given 1 month apart] of four infusions at weekly intervals, followed by a Flexible period of re-cycling in case of worsening). Eight patients were positive for acetylcholine receptor antibody, four for muscle-specific tyrosine kinase antibody, and two for lipoprotein-related protein 4 antibody, and five were classified as triple negative. Efficacy of EFG was assessed by the Myasthenia Gravis Activities of Daily Living, Myasthenia Gravis Composite, and Quantitative Myasthenia Gravis scales.

RESULTS

Fifty-three percent of patients needed three treatment cycles, 26% needed four, and 21% needed five along the 14-month clinical follow-up. Meaningful improvement was observed at the end of each cycle with the clinical scores adopted. EFG had a dramatic effect on disease course, as during the year before treatment eight of 19 patients (42%) were hospitalized, and 15 of 19 (79%) needed treatment with plasma exchange or immunoglobulins; three of 19 (16%) were admitted to the intensive care unit. During EFG, none of the patients was hospitalized and only one patient required plasma exchange and intravenous immunoglobulins. No major side effects or infusion-related reactions occurred.

CONCLUSIONS

We observed that EFG was safe and modified significantly the course of the disease along a 14-month follow-up. Our experience strengthens the role of FcRn inhibition as an effective new tool for long-term treatment of gMG.

Efgartigimod is a new option for the treatment of thymoma associated myasthenia gravis: A case report

INTRODUCTION

The perioperative efficacy and safety of efgartigimod in patients with thymoma associated myasthenia gravis have not been reported.

CASE PRESENTATION

We described the case of a 47-year-old woman who presented thymoma associated myasthenia gravis. Primarily, the patient was treated with acetylcholinesterase inhibitors, immunosuppressive medications, and intravenous immunoglobulin. Unfortunately, the control of symptoms was unsatisfactory. The patient was treated with recommended dosage of efgartigimod (10 mg/kg administered as a 1 h intravenous infusion once weekly for 2 weeks) combined with immunosuppressive therapy. Consequently, improved outcomes and rapid clinical remission were observed. Then, modified subxiphoid thoracoscopic thymectomy was performed smoothly and the patient was discharged from hospital after recovery in short time.

DISCUSSION

Administration of efgartigimod could control symptoms significantly and rapidly. Efgartigimod provides the opportunity of thymectomy in short time. Importantly, there was no any perioperative complication or any adverse event related to efgartigimod.

CONCLUSION

The improved outcomes of the patient with thymoma associated myasthenia gravis highlight the importance of efgartigimod. Large-scale clinical trials are needed to validate the safety and efficacy of efgartigimod during the perioperative period of thymectomy.

Efgartigimod beyond myasthenia gravis: the role of FcRn-targeting therapies in stiff-person syndrome

Stiff-person syndrome (SPS) is a rare autoimmune neurological disorder characterized by high titers of antibodies against glutamic acid decarboxylase (GAD) causing impaired GABAergic inhibitory neurotransmission. To date, there is not a defined therapy for such condition, but immunomodulating therapies, such as plasma exchange, intravenous immunoglobulins, and rituximab, have been widely used in clinical practice. However, the efficacy and tolerability of these treatments is not well established. Efgartigimod, a new neonatal Fc receptor (FcRn) blocker, is a human IgG1 antibody Fc fragment engineered with increased affinity for FcRn binding, leading to a reduction in IgGs levels, including pathogenic IgG autoantibody showing promising results in neurological autoimmune disorders and has been approved for the treatment of AChR-seropositive generalized myasthenia gravis (MG). In this study, we report and describe the first data on treatment with efgartigimod in three patients affected by both AChR-seropositive generalized MG and anti-GAD-seropositive SPS. Patients were followed since the start of efgartigimod and for the whole treatment period (12 weeks). MG symptoms were assessed with the "MG activity of daily living score" and the Quantitative Myasthenia Gravis score, while SPS ones were assessed with the "SPS activity of daily living score"; muscle strength was assessed with the Medical Research Council Sum score; the overall disability from MG and SPS was assessed by the modified Rankin Scale. All patients showed an improvement in symptoms of both SPS and MG after 2 cycles of treatment. Our data suggest that efgartigimod may be considered as a candidate drug for SPS and other autoantibody-mediated neurological disorders.

Therapeutic modalities in thrombotic thrombocytopenic purpura management among Jehovah's Witness patients: A review of reported cases

INTRODUCTION

Devout members of the Jehovah's Witness faith flatly refuse transfusions of white blood cells, red blood cells, platelets, and plasma. The latter agent is a mainstay in the treatment of thrombotic thrombocytopenic purpura (TTP). Alternative treatment options for Jehovah's Witness patients are needed and reviewed herein.

METHODS

Cases of TTP treatment among Jehovah's Witnesses were obtained from the published literature. Key baseline and clinical data were extracted and summarized.

RESULTS

A total of 13 reports spanning a 23-year period and 15 TTP episodes were identified. Median (IQR) age was 45.5 (29.0-57.5) and 12/13 (93%) patients were female. Neurologic symptoms were present in 7/15 (47%) episodes at presentation. Disease confirmation with ADAMTS13 testing was present in 11/15 (73%) of episodes. Corticosteroids and rituximab were employed in 13/15 (87%) and 12/15 (80%) of cases, respectively, with apheresis-based therapy employed in 9/15 (60%) episodes. For eligible cases, caplacizumab was used in 4/5 (80%) episodes; average time to platelet response was shortest in these cases. Sources of exogenous ADAMTS13 accepted by patients in this series included cryo-poor plasma, FVIII concentrate, and cryoprecipitate.

CONCLUSIONS

Successful management of TTP within the boundaries of the Jehovah's Witness faith is possible.