Based on results reported by ADVANCE IV Clinical Trial, which was conducted worldwide, including at Georgetown University Medical Center.
People with ITP have a type of autoantibody (antibodies against a person’s own proteins) called immunoglobulin G (IgG) that increases the removal of platelets from circulation and can also reduce platelet production. ITP can be very difficult to treat, especially in patients who have not responded well to previous treatments for ITP.
The study results were presented during a plenary session of the American Society of Hematology annual meeting in New Orleans on Dec. 11, 2022, by Catherine Broome, MD, Georgetown associate professor of medicine and researcher lead of the international ADVANCE IV study.
The results of the ADVANCE IV study provide an important answer regarding the potential benefits of efgartigimod as a treatment for ITP. There remains a significant unmet need in the treatment of ITP. ITP is also associated with debilitating fatigue and can have significant impacts on mental health, including anxiety, fear and depression, which is why finding additional therapies to treat the condition has been so critical. .”
Catherine Broome, MD, associate professor of medicine, Georgetown University Medical Center
The annual rate of newly diagnosed cases of ITP in the United States is estimated to be approximately 3.3 new cases per 100,000 people in the general population. Between adolescence and 60 years, ITP is more common in women.
Efgartigimod has a new mechanism of action. It lowers IgG levels without affecting important immune system components such as lymphocytes, IgG production or the body’s innate immune system.
ADVANCE IV is a double-blind phase III clinical trial involving 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 trial had low platelet counts and had at least one ITP treatment before being randomized into the trial; two-thirds of participants had received at least three prior treatments for ITP.
The study was sponsored by argenx, which developed efgartigimod. The drug, sold under the brand name Vyvgart, has only been approved for the treatment of a form of myasthenia gravis, a condition caused by autoantibodies and resulting in a breakdown of communications between nerves and muscles.
In the ADVANCE IV trial, patients with chronic ITP who received efgartigimod versus placebo achieved a significant improvement in sustained platelet response (21.8% versus 5%, respectively) over at at least four of the last six scheduled trial visits, with approximately 50% of those who responded to the drug seeing doubled platelet counts. Drug response was observed in all types of patients, regardless of age, disease severity, time since diagnosis, prior treatment for ITP, or use of other medications. The most commonly reported side effects of the drug included bruising, headache, blood in the urine, and rash-like symptoms related to bleeding. No serious treatment-related side effects were reported.
“Our hope is that as more therapies become available for patients with ITP, fewer patients will experience bleeding events and fatigue, leading to an overall increase in their quality of life,” Broome says.
The drug was administered intravenously in this trial. There is a concurrent trial that administers the drug subcutaneously, or just under the skin, to see if administration this way is comparable to intravenous administration. The results of the subcutaneous study are expected in the second half of 2023.
“Our next step is already underway,” says Broome, who treats patients at MedStar Georgetown University Hospital. “ADVANCE-plus is an open-label extension of this trial, which will provide data on the long-term efficacy and safety of efgartigimod by observing participants for up to 60 weeks compared to the 24 weeks we are currently reporting on.
In addition to Broome, authors include Vickie McDonald, Barts Health NHS Trust, London, UK; Yoshitaka Miyakawa, Saitama Medical University Hospital, Saitama, Japan; Monica Carpenedo, ASST St. Gerard Hospital, Monza, Italy; David J. Kuter and Hanny Al-Samkari Massachusetts General Hospital, Boston; James B. Bussel, Weill Cornell Medicine, New York, NY; , Marie Godar, Jaume Ayguasanosa and Christophe De Beuf, Argentina, Ghent, Belgium; Francesco Rodeghiero, Hematology Project Foundation, Affiliated Department of Hematology, S. Bortolo Hospital, Vicenza, Italy; Marc Michel, National Reference Center for Immune Cytopenias, CHU Henri Mondor, Public Aid – Hospitals of Paris, Paris-Est Créteil University, Créteil, France; and Adrian C. Newland, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, UK.
This research was supported by argenx.