An Argenx drug for the treatment of rare neuromuscular disease systemic myasthenia gravis is now on the market Approved by the U.S. Food and Drug Administration, The first therapy among new drugs that adopt new methods to treat autoimmune diseases.
Myasthenia gravis occurs when the body produces autoantibodies that interfere with the way nerves and muscles communicate. This disease can cause severe attacks of weakness, difficulty swallowing and breathing, and can be life-threatening. The Argenx drug efgartigimod caused a reduction in the level of antibodies associated with myasthenia gravis. Argenx will market its new drug under the name “Vyvgart”-the first product of the Dutch-based company.
There are treatments for the early forms of myasthenia gravis. Acetylcholinesterase inhibitor drugs can prevent the breakdown of key neurotransmitters for muscle contraction, but they can cause gastrointestinal side effects, including vomiting, diarrhea, and abdominal pain. This treatment is followed by corticosteroids and immunosuppressants. Steroids can cause bone thinning and weight gain, and can cause problems such as diabetes and high blood pressure. Immunosuppressants can cause elevated liver enzymes and increase susceptibility to infection.
Treatment of advanced cases of myasthenia gravis includes intravenous antibody injection and plasma exchange, a procedure that removes and filters blood. Both of these treatments carry the risk of complications.
The body has an internal way of processing proteins, including antibodies. It usually removes antibodies from the circulation by bringing them into the cell, where they are either degraded by the lysosome, which is a cell processing system, or recycled back into the circulation. A protein called neonatal Fc receptor (FcRn) is the key to this recovery process. Antibodies that bind to FcRn are recovered into the circulation. Those cells that are not bound to FcRn will be degraded by the cell’s processing system.
Vyvgart is an antibody fragment discovered and developed based on Argenx’s proprietary technology. It is Llama-based immune systemArgenx designed Vyvgart to bind to FcRn, thereby preventing the recycling of antibodies that cause myasthenia gravis. Those unbound antibodies in turn enter the lysosome for degradation.
The FDA approved Vyvgart to cover adults who have tested positive for a specific antibody that causes loss of muscle function: anti-acetylcholine receptor (AChR) antibodies. Argenx said in a report that of the estimated 65,000 patients with myasthenia gravis in the United States, about 17,000 of them were positive for AChR antibodies. Investor introduction. This is the same group of patients treated by Soliris. Soliris is Alexion Pharmaceuticals’ blockbuster in the treatment of multiple autoimmune diseases Approved for myasthenia gravis In 2017, Alexion’s antibody drugs worked in different ways, binding to the complement system protein C5 to block the immune response generated by myasthenia gravis.
Argenx tested Vyvgart in a placebo-controlled phase 3 clinical trial, which enrolled 167 patients. The goal of this 26-week study is to evaluate patients based on a survey that grades the symptoms of myasthenia gravis. In this study, nearly 68% of patients who received Argenx drugs responded to the treatment, compared with only 30% of patients who received a placebo. Based on the measurement of muscle weakness, the results are also in favor of Vyvgart.Last June, the result of this study was Publish In the journal The Lancet Neurology.
The side effects reported in the study—respiratory tract infections, headaches, and urinary tract infections—are comparable in the two groups. However, Vyvgart also binds to immunoglobulin G (IgG), an antibody that prevents pathogens from infecting the body. The FDA warned that because the Argenx drug reduces IgG levels, patients face a greater risk of infection. Vyvgart’s drug label does not have a black box warning of dangerous side effects.
Vyvgart was the first drug approved by the FDA to work by blocking FcRn, but a competitor’s drug aimed at the same target followed closely behind. Earlier this month, UCB Report data From its phase 3 test of subcutaneous injection of FcRn targeting antibody rozanolixizumab. Preliminary results indicate that the drug has achieved its main goal, which is to show a statistically significant change in the score based on the assessment of myasthenia gravis. The Belgian drugmaker said it expects to submit regulatory applications in the United States, Europe and Japan in the third quarter of 2022.
Momenta Pharmaceuticals’ main drug, nipocalimab, is the core drug that Johnson & Johnson acquired for US$6.5 billion last year.. Intravenously infused FcRn-targeted antibodies are being developed for a variety of autoimmune diseases, including myasthenia gravis.
Keith Wood, chief operating officer of Argenx, said on Friday’s conference call that Vyvgart’s annual net price for typical patients is $225,000. The actual price will vary based on many factors, including the weight of the patient and the number of treatment cycles required, as well as insurance coverage, rebates and discounts. But Woods said that Argenx has reached agreement in principle with payers in many countries and regions. The agreement outlines a value-based agreement in which the reimbursement of the product is linked to the benefits shown by the treatment to the patient. Woods explained that the value-based agreement will limit the risk that payers will pay for treatment for patients who need more medication.
Argenx has other plans for its main drugs. A subcutaneous version is currently in the later stages of testing, and preliminary results are expected to be announced in the first half of 2022. Clinical trials are also evaluating efgartigimod in five other rare diseases. CEO Tim Van Hauwermeiren said that Argenx’s goal is to expand the use of its new drugs to as many as 15 indications by 2025.
Photo from Argenx investor introduction
