Ouro Medicines' Gamgertamig Receives Second FDA Orphan Drug Designation for Immune Thrombocytopenia
核心洞察
Ouro Medicines (搜索) announced that gamgertamig (搜索) (OM336), a BCMAxCD3 T cell engager antibody, received FDA Orphan Drug Designation for immune thrombocytopenia (搜索) (ITP) treatment.
This marks the second orphan designation for gamgertamig (搜索), following previous approval for autoimmune hemolytic anemia (搜索), both conditions being evaluated in an ongoing Phase 1b basket study.
The investigational bispecific antibody features a "detuned" CD3 (搜索)-targeting arm designed to minimize immune activation while maintaining target cell depletion potency.
Ouro Medicines (搜索) announced that its investigational BCMAxCD3 T cell engager antibody candidate, gamgertamig (搜索) (OM336), has received U.S. Food and Drug Administration Orphan Drug Designation for the treatment of immune thrombocytopenia (搜索) (ITP). This designation represents the second orphan drug status granted to gamgertamig, following a previous designation for autoimmune hemolytic anemia (搜索) (AIHA).
"The FDA's decision to grant Orphan Drug Designation to gamgertamig (搜索) for development in the treatment of ITP means that gamgertamig has now received ODD for two indications in our ongoing Phase 1b autoimmune cytopenias (搜索) basket study," said Jaideep Dudani, Ph.D., Chief Executive Officer of Ouro Medicines (搜索). "This second designation underscores the promise for gamgertamig to address unmet needs in ITP, offering an immune reset approach with differentiated properties as a clinical candidate."
Clinical Development Progress
The company has completed dosing in the first cohort of its Phase 1b autoimmune cytopenias (搜索) basket study, with enrollment actively ongoing in the second cohort. The open-label, multi-site study is being conducted in the United States and Australia, evaluating safety, tolerability and pharmacokinetics of gamgertamig (搜索) in adult participants with active autoimmune cytopenias, specifically relapsed/refractory ITP, AIHA, or both conditions (NCT07083960).
The study administers gamgertamig (搜索) via subcutaneous injection in ascending dose cohorts, with the primary endpoint evaluated at Week 12. Exploratory endpoints include clinical efficacy measures and blood biomarkers. Ouro Medicines (搜索) continues to expect results from this study in 2026.
Mechanism of Action and Design Features
Gamgertamig (搜索) is an investigational BCMAxCD3 bispecific antibody designed to induce T cell-dependent cellular cytotoxicity of cells expressing BCMA (搜索), which are thought to drive certain immune-mediated diseases through the production of autoantibodies. By depleting these cell populations, the therapy may offer patients extended periods of relief while avoiding the challenges associated with immunosuppressive treatments.
The antibody incorporates a distinctive "detuned" CD3 (搜索)-targeting arm engineered for reduced induction of T cell cytokines. This design aims to avoid severe immune activation while retaining potency of target cell depletion, potentially contributing to an expanded therapeutic index. Additionally, gamgertamig (搜索) has a long half-life that enables subcutaneous dosing and includes properties that may contribute to improved safety and tolerability.
Disease Background and Unmet Medical Need
Autoimmune cytopenias (搜索) are diseases resulting primarily from autoantibody-mediated destruction of blood cells. ITP occurs when the body's immune system attacks platelets, the blood cells that help control bleeding, leading to low platelet counts and potentially life-threatening hemorrhagic episodes. The condition is driven by autoantibodies that cause destruction of platelets, resulting in signs and symptoms including bleeding and fatigue.
AIHA affects red blood cells, with autoantibodies leading to premature destruction of the body's red blood cells through a process known as hemolysis. Individuals with AIHA may experience debilitating fatigue, thromboembolism, dizziness, palpitations and shortness of breath. Both conditions are potentially life-threatening.
Regulatory Benefits and Company Background
The FDA Orphan Drug Designation program is intended to advance therapeutics developed to treat, prevent or diagnose diseases that affect fewer than 200,000 people in the United States. The designation provides benefits including seven years of marketing exclusivity following a potential approval.
Gamgertamig (搜索) has a record of clinical evaluation across investigator-initiated and company-sponsored studies in oncology and immune-mediated diseases, contributing to understanding of its properties and potential applications.
Ouro Medicines (搜索) is a biotechnology company dedicated to developing immune reset therapeutics for people living with chronic immune-mediated diseases. The company's approach focuses on leveraging T cell engagers in B cell-mediated diseases to achieve immune resets that create durable remissions without ongoing immunosuppression. Based in San Francisco and launched in 2025, Ouro was founded by Monograph Capital in partnership with GSK and is backed by leading investors TPG, NEA and Norwest.