The European Medicines Agency (EMA) has granted orphan drug status to KYV-101, an experimental cell therapy developed by Kyverna Therapeutics, for the treatment of myasthenia gravis (MG). This designation aims to support the development of treatments for rare, life-threatening, or chronically debilitating conditions affecting no more than five in every 10,000 people in the European Union.
Benefits of Orphan Drug Status
Orphan drug status provides several key benefits to Kyverna Therapeutics, including assistance with trial protocols, reduced regulatory fees, and a 10-year period of market exclusivity in Europe upon approval. The U.S. Food and Drug Administration (FDA) has also granted KYV-101 orphan drug designation, which confers similar benefits, including a seven-year market exclusivity period in the U.S.
Warner Biddle, CEO of Kyverna, stated in a company press release, “With KYV-101 advancing towards later stages of development, we are scaling Kyverna to bring the transformative impact of our differentiated CAR T therapies to patients with a range of B cell-driven autoimmune diseases.”
Understanding Myasthenia Gravis and KYV-101
Myasthenia gravis is an autoimmune disease characterized by autoantibodies that disrupt communication between nerve and muscle cells at the neuromuscular junction. These antibodies most commonly target acetylcholine receptors (AChRs) and, less frequently, muscle-specific kinase (MuSK), leading to muscle weakness and fatigue.
KYV-101 is an investigational chimeric antigen receptor (CAR) T-cell therapy designed to reduce the levels of antibody-producing B-cells, thereby alleviating the severity of MG. The therapy involves extracting a patient's T-cells and engineering them to express a CAR that targets CD19, a protein found on the surface of B-cells. These modified T-cells are then infused back into the patient to specifically recognize and destroy B-cells.
Clinical Development and Trial Design
KYV-101 is administered as a single intravenous infusion following a short course of chemotherapy to deplete existing immune cells. The therapy is currently being evaluated in a Phase 2 clinical trial called KYSA-6 (NCT06193889). This trial aims to enroll 20 patients, aged 18 to 75, with treatment-resistant generalized MG who test positive for autoantibodies targeting AChR or MuSK. The trial is being conducted at sites in the U.S. and Germany.
The primary goals of the KYSA-6 trial are to assess the safety and efficacy of KYV-101, as measured by changes in the Myasthenia Gravis Activities of Daily Living (MG-ADL) scale scores over six months. The MG-ADL scale is a patient-reported outcome measure that assesses the impact of MG on a patient's ability to perform daily functions. Safety assessments will continue for up to two years.
Regulatory Designations
In addition to orphan drug designation, KYV-101 has received fast track and regenerative medicine advanced therapy (RMAT) designations from the FDA. These designations are intended to expedite the development and regulatory review of the therapy.
Kyverna Therapeutics is also investigating KYV-101 as a potential treatment for other autoimmune conditions, including lupus nephritis, systemic sclerosis, multiple sclerosis, and stiff person syndrome.
