#United States #South San Francisco #Ouro Medicines #Sjögren's Disease #OM336

Ouro Medicines Expands Clinical Development of OM336

Ouro Medicines, a cutting-edge biotechnology firm focused on immune reset therapeutics for individuals with chronic, immune-mediated diseases, has taken a significant step in enhancing its clinical efforts. The company has recently announced the commencement of a multinational Phase 1b study of OM336, a promising BCMAxCD3 T-cell engager antibody, targeting Sjögren's disease and idiopathic inflammatory myopathy (IIM).

Both Sjögren's disease and IIM are autoimmune diseases mediated by B and plasma cells. These conditions impose a heavy burden on patients and currently have limited treatment alternatives. Dr. Neely Mozaffarian, Chief Medical Officer of Ouro Medicines, shared, “This study reflects Ouro's strategy of expanding OM336 development to additional immune-mediated diseases where an 'immune reset' approach would be transformative.” The innovative treatment involves the transient depletion of memory B cells and plasma cells, presenting the potential for long-lasting remission for patients grappling with these challenging conditions.

In a statement, Jaideep Dudani, CEO of Ouro Medicines, emphasized the company’s commitment to redefining care standards for patients with immune-mediated diseases. “This additional study, expanding beyond autoimmune cytopenias, underscores our dedication to exploring high-need conditions,” he remarked. With initial results from this Phase 1b study anticipated in 2026, Ouro aims to leverage OM336 across various indications, possibly establishing a new class of therapy.

The Phase 1b study will be open-label and multi-site, employing a basket design to assess the safety, tolerability, and pharmacokinetics of OM336 among adult participants suffering from autoantibody-positive, relapsed/refractory cases of Sjögren's disease or IIM, which includes dermatomyositis, polymyositis, immune-mediated necrotizing myopathy, and anti-synthetase syndrome. The administration of OM336 will occur via subcutaneous injection in ascending dose levels over the first three weeks, with follow-up evaluations extending up to Week 52. Exploratory endpoints will focus on clinical efficacy, patient-reported outcomes, and biomarkers pertinent to each indication.

Previously, Ouro had initiated clinical development with OM336 focusing on autoimmune cytopenias (AIC)—including autoimmune hemolytic anemia (AIHA) and immune thrombocytopenia (ITP). The trial, actively enrolling participants, has shown promising responses in patients with severe and refractory cases of AIC, with results expected in 2026.

Understanding OM336

OM336 is an investigational BCMAxCD3 bispecific antibody designed to trigger T cell-dependent cytotoxicity against target cells expressing BCMA. Its CD3-targeting arm has been engineered to minimize T cell cytokine induction, referred to as a 'detuned' mechanism, thus avoiding severe immune activation while still effectively depleting target cells. With a long half-life facilitating subcutaneous dosing, OM336 may boast safety and tolerability benefits.

To date, over 100 patients have received OM336 across various clinical studies in oncology and immune-mediated conditions, including cases of AIHA and ITP. The U.S. FDA has granted OM336 Orphan Drug Designation (ODD) for AIHA treatment, highlighting its potential in the therapeutic landscape.

What Are Sjögren's Disease and IIM?

Sjögren's disease represents a common chronic autoimmune condition characterized by the immune system's attack on the body’s exocrine glands, manifesting as severe dry eyes and mouth. In addition to gland dysfunction, it can lead to serious organ involvement affecting the musculoskeletal, pulmonary, cardiovascular, renal, and gastrointestinal systems. Current treatments mainly focus on managing symptoms and employing broadly immunosuppressive therapies, which can induce significant side effects and offer insufficient disease control.

Conversely, idiopathic inflammatory myopathy (IIM) is a group of rare and chronic autoimmune diseases marked by immune-mediated damage to healthy muscle tissue. This leads to progressive muscle weakness, chronic inflammation, and significant impairment of function. IIM can also involve critical organs beyond muscle, including the lungs, heart, skin, and joints, potentially resulting in life-threatening complications. Current treatments largely depend on broad immunosuppressive therapies, including corticosteroids, which often provide incomplete control and entail considerable adverse effects.

About Ouro Medicines

Founded in 2025 and based in San Francisco, Ouro Medicines is a biotechnology company dedicated to developing immune reset therapies for patients enduring chronic immune-mediated diseases. The company's approach emphasizes T cell engagers in B cell-mediated diseases to facilitate immune resets that induce durable remissions without the need for continuous immunosuppression. Backed by significant investment partners including GSK, TPG, NEA, and Norwest, Ouro is forging new pathways in the treatment of autoimmune diseases, aiming to improve patient outcomes through innovative therapeutic strategies.

For further details, visit www.ouromedicines.com.