Ouro starts Phase 1b trial of OM336 for Sjögren’s disease treatment
Basket trial also testing therapy for idiopathic inflammatory myopathy
An experimental therapy from Ouro Medicines is being tested in a Phase 1b clinical trial on people who have Sjögren’s disease and idiopathic inflammatory myopathy (IMM), another autoimmune condition.
“This study reflects Ouro’s strategy of expanding OM336 development to additional immune-mediated diseases where an ‘immune reset’ approach would be transformative,” Neely Mozaffarian, MD, PhD, Ouro’s chief medical officer, said in a company press release.
“We expect initial interim results from this Phase 1b study in Sjögren’s and idiopathic inflammatory myopathy in 2026,” said Jaideep Dudani, PhD, Ouro’s CEO.
The study will be multinational, according to Ouro, but the company has not yet shared details about where the sites are located or how many participants will be enrolled.
Sjögren’s disease is an autoimmune disorder that most commonly causes damage in tear- and saliva-producing glands but can affect other parts of the body. The disease is typically characterized by self-reactive antibodies — anti-Ro (SS-A) and anti-La (SS-B) — which are thought to drive the immune attack against the body’s own tissues.
The OM336 mechanism: Targeting B-cells with T-cells
OM336 is an antibody-based therapy administered through under-the-skin injections. It is designed to deplete B-cells, the immune cells responsible for producing all antibodies, including the self-reactive antibodies that drive Sjögren’s and other autoimmune diseases.
The therapy is designed to simultaneously bind to two targets: BCMA, a protein at the surface of B-cells, and CD3, which is found at the surface of other immune cells (called T-cells). By binding both targets at the same time, the therapy seeks to trigger T-cells to destroy B-cells, thereby reducing levels of self-reactive antibodies and lessening disease activity.
“Through [temporary] depletion of [several subsets of B-cells], OM336 has the potential to deliver long-lasting remission to patients living with these challenging conditions,” Mozaffarian said.
The basket Phase 1b trial will assess the safety, tolerability, and pharmacological profile of increasing doses of OM336 in people with Sjögren’s or IMM, a group of autoimmune disorders marked by chronic muscle inflammation and weakness. The study will also evaluate changes in clinical measures, patient-reported outcomes, and disease biomarkers.
Eligible participants are those with relapsed or treatment-resistant disease and who are positive for self-reactive antibodies associated with each disease. They will receive OM336 for three weeks and then be monitored for about one year.
OM336 is already being tested in another Phase 1b trial (NCT07083960) involving adults with autoimmune cytopenias, a group of autoimmune disorders — including cold agglutinin disease, which is marked by attacks on healthy blood cells.
The new trial, “expanding beyond autoimmune cytopenias, is our second study to begin in less than a year following corporate launch and underscores Ouro’s commitment to redefine the standard of care for patients with immune-mediated diseases,” Dudani said. “As we expand to additional indications, also with high need and compelling opportunity for OM336, we continue to be focused on our goal of bringing this candidate into investigation for a wide range of indications as a potentially new class of therapy.”
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