SHANGHAI, China, May 19, 2026 — ImmuneOnco Biopharmaceuticals (Shanghai) Inc. ("ImmuneOnco"; HKEX Stock Code: 01541.HK) today announced that the first patient has been successfully enrolled and dosed in a Phase II randomized controlled clinical trial evaluating its proprietary drug, amourofavfop alfa (IMM0306), for the treatment of active systemic lupus erythematosus (SLE).

Amourofavfop alfa (CD47xCD20, IMM0306) is the world's first CD47xCD20 dual-target specific molecule to enter clinical development, developed based on ImmuneOnco's proprietary "mAb-Trap" technology platform. Preliminary data from the Phase Ib/II clinical study in SLE, released in 2025, demonstrated positive efficacy and a favorable safety profile, with no observed cytokine release syndrome (CRS) or serious infection events, highlighting the therapeutic potential and clinical value of this product in SLE. Updated Phase Ib clinical data will also be presented at the 2026 EULAR Congress.

According to the protocol, this Phase II randomized controlled study plans to enroll 90 patients, who will be randomly assigned in a 1:1:1 ratio to three treatment arms receiving either 1.2 mg/kg or 1.6 mg/kg of IMM0306, or a placebo. The study aims to further evaluate the efficacy and safety of IMM0306 in patients with moderate-to-severe active SLE in a scientific and rigorous manner, providing robust data support for Phase III clinical development.

Currently, ImmuneOnco is comprehensively advancing the diversified layout of IMM0306 in the field of autoimmune diseases. In addition to SLE, the drug has received clinical approvals for multiple blockbuster indications, including IgG4-related disease (IgG4-RD), membranous nephropathy, and primary Sjögren's syndrome (pSS). Meanwhile, the clinical development of a subcutaneous formulation of IMM0306 is also underway, which is expected to further improve long-term medication adherence and enhance the treatment experience for patients.

Dr. Tian Wenzhi, Chairman, CEO, and CSO of ImmuneOnco, stated:

"The successful enrollment of the first patient in the Phase II SLE study marks a significant step forward in advancing our autoimmune disease pipeline. With its unique advantages in deep B-cell depletion and immune reconstitution, IMM0306 holds the promise of delivering a breakthrough therapeutic option for patients suffering from SLE. We will continue to efficiently advance our various clinical studies, striving to benefit a broad population of patients as soon as possible."

Dr. Wu Zhuli, Chief Medical Officer of ImmuneOnco, stated:

"The pathogenesis of systemic lupus erythematosus (SLE) is closely associated with abnormal B-cell activation and the production of autoantibodies. As an innovative bispecific fusion protein, IMM0306 can simultaneously target CD47 and CD20, delivering a 'double strike' against pathogenic B cells and plasmablasts. This mechanism holds the potential to overcome the efficacy bottlenecks of single-target drugs, achieving deeper and more durable clinical remission while reducing the reliance on corticosteroids. We look forward to this Phase II study further validating the clinical efficacy and safety of IMM0306 in the treatment of SLE."