HomeENGLISH MAGAZINEEfgartigimod: the new antibody fragment to handle trombopenic purpura leaving immunity alone

Efgartigimod: the new antibody fragment to handle trombopenic purpura leaving immunity alone

The annual rate of newly diagnosed cases of primary chronic immune thrombocytopenia (TIP) worldwide is estimated to be between 1 and 5 new cases per 100,000. Between the teens and 60s, TIP is more common in women. People with TIP have a type of immunoglobulin G (IgG) class autoantibody that increases the destruction of platelets from the circulation and can also reduce platelet production. ITP can be very difficult to treat, especially in patients who have not responded well to previous TIP therapies. Now, according to results reported from the ADVANCE IV clinical trial, which was conducted globally, including at Georgetown University Medical Center. Patients taking efgartigimod, a drug now being studied for the treatment of TIP, showed significantly greater improvement in platelet counts, which are essential for clotting and stopping bleeding, than those taking a placebo.

The study results were presented at a plenary session of the American Society of Hematology’s annual meeting in New Orleans last Dec. 11. ADVANCE IV is a phase III, double-blind clinical study enrolling 131 patients in North America, Europe and Japan. Participants were randomly assigned to receive either efgartigimod or a placebo for a total of 24 weeks. All patients in the study had low platelet counts and had received at least one anti-TIP drug before being randomly assigned to the study; two-thirds of enrollees had received three or more prior therapies. The trial was led by Catherine Broome, a leader and associate professor of medicine at Georgetown University. The study was sponsored by the pharma company Argenx, which developed this biological derivative which is an antibody fragment designed to reduce pathogenic immunoglobulin G (IgG) antibodies by binding to the neonatal Fc receptor and blocking the IgG recycling process.

Efgartigimod has a new mechanism of action. Lowers IgG levels without affecting lymphocytes, IgG production or the body’s innate immune system. The drug, sold under the brand name Vyvgart, has only been approved to treat one form of myasthenia gravis, a condition caused by autoantibodies. In the ADVANCE IV study, patients with chronic TIP who received efgartigimod versus placebo achieved a significant improvement in sustained platelet response (21.8% vs. 5%, respectively), during at least four of the last six scheduled study visits, with approximately 50% of those who responded to the drug saw a doubled platelet count. Response to the drug was observed in all patient types regardless of age, disease severity, time since diagnosis, and prior treatment. The most commonly reported side effects included bruising, headache, blood in the urine and rash-like symptoms.

The drug was administered intravenously in this study, and no serious treatment-related side effects were reported. There is a concurrent trial administering the drug subcutaneously, to see if administering this way is comparable to intravenous administration. The results of the subcutaneous study are expected in the second half of 2023. Dr. Broome expressed her hopes thus: “Our next step is already underway”, ADVANCE-plus is an open-label extension of this study, which will provide data on the long-term efficacy and safety of efgartigimod by observing participants for up to 60 weeks versus the 24 weeks we are reporting now. Our hope is that as more therapies become available to patients with TIP, fewer patients will experience bleeding events and fatigue, leading to an overall improvement in their quality of life.”

  • edited by Dr. Gianfrancesco Cormaci, PhD, specialist in Clinical Biochemistry.

Scientific references

Dalakas MC. Expert Rev Clin Immunol. 2022 Jul; 18(7):691-701.

Demain JG et al. J Allergy Clin Immunol Pract. 2022; 10(7):1930.

Maho-Vaillant M et al. Front Immunol. 2022 May 18; 13:863095.

Briani C, Visentin A. Neurotherapeutics. 2022 Apr; 19(3):874-884.

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Dott. Gianfrancesco Cormaci

Medico Chirurgo, Specialista; PhD. a CoFood s.r.l.
- Laurea in Medicina e Chirurgia nel 1998 (MD Degree in 1998) - Specialista in Biochimica Clinica nel 2002 (Clinical Biochemistry residency in 2002) - Dottorato in Neurobiologia nel 2006 (Neurobiology PhD in 2006) - Ha soggiornato negli Stati Uniti, Baltimora (MD) come ricercatore alle dipendenze del National Institute on Drug Abuse (NIDA/NIH) e poi alla Johns Hopkins University, dal 2004 al 2008. - Dal 2009 si occupa di Medicina personalizzata. - Guardia medica presso strutture private dal 2010 - Detentore di due brevetti sulla preparazione di prodotti gluten-free a partire da regolare farina di frumento enzimaticamente neutralizzata (owner of patents concerning the production of bakery gluten-free products, starting from regular wheat flour). - Responsabile del reparto Ricerca e Sviluppo per la società CoFood s.r.l. (Leader of the R&D for the partnership CoFood s.r.l.) - Autore di articoli su informazione medica e salute sul sito www.medicomunicare.it (Medical/health information on website) - Autore di corsi ECM FAD pubblicizzati sul sito www.salutesicilia.it
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