SystImmune to Receive Milestone Payment from Bristol Myers Squibb Under Iza-Bren Collaboration

REDMOND, Wash., Oct. 13, 2025 /PRNewswire/ -- SystImmune, Inc., a clinical-stage biotechnology company, today announced the treatment of the first patient in the IZABRIGHT-Breast01 study (NCT06926868), a global Ph2/3 registrational study of izalontamab brengitecan (iza-bren) in previously untreated triple negative breast cancer ineligible for anti-PD(L)1 drugs. This milestone triggered a one-time payment of $250 million by Bristol Myers Squibb (NYSE: BMY), pursuant to the 2023 collaboration and exclusive license agreement between SystImmune and Bristol Myers Squibb. SystImmune is further eligible to receive up to an additional $250 million in contingent near-term payments and additional payments of up to $7.1 billion contingent upon the achievement of certain development, regulatory and sales performance milestones.

Iza-bren is a potential first-in-class bispecific topoisomerase 1 inhibitor-based antibody-drug conjugate (ADC) that targets both epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 3 (HER3). It is being developed by SystImmune's parent company, Sichuan Biokin Pharmaceutical Co., Ltd. (Biokin) in China and jointly developed by SystImmune and Bristol Myers Squibb in territories outside of China.

"This milestone marks a significant step forward in the global clinical development of iza-bren," said Dr. Yi Zhu, Chairman, SystImmune. "The robust data generated from our China-based trials have played an important role in accelerating development timelines and informing global strategy. We are encouraged by the achievement of this milestone and Bristol Myers Squibb's commitment to this program. We look forward to bringing iza-bren to patients worldwide under our shared vision with Bristol Myers Squibb."

"Together with Bristol Myers Squibb, we have made significant progress in developing iza-bren globally. We remain deeply committed to delivering this potentially transformative therapy to patients with triple negative breast cancer and other solid tumors," said Dr. Jie D'Elia, CEO, SystImmune. "This $250 million milestone not only reflects the progress of our collaboration but also significantly reinforces our financial position, enabling us to accelerate the global development of our differentiated ADC portfolio."

Iza-bren is currently being evaluated in multiple ongoing clinical trials, including BL-B01D1-LUNG-101 (NCT05983432), IZABRIGHT-Lung01 (NCT07100080), IZABRIGHT-Bladder01 (NCT07106762), and studies in China conducted by Biokin. The program recently received Breakthrough Therapy Designation from the U.S. Food and Drug Administration for the treatment of patients with previously treated advanced EGFR-mutated non-small cell lung cancer.

About iza-bren
SystImmune, in collaboration with BMS outside of China, is developing iza-bren (BL-B01D1), a bispecific antibody-drug conjugate (ADC) that targets both EGFR and HER3, which are highly expressed in various epithelial cancers and are known to be associated with cancer cell proliferation and survival. Iza-bren's dual mechanism of action blocks EGFR and HER3 signals to cancer cells, reducing proliferation and survival signals. In addition, upon antibody mediated internalization, iza-bren's therapeutic novel Topo1i payload is released causing cytotoxic stress that leads to cancer cell death.

About SystImmune
SystImmune is a clinical-stage biopharmaceutical company located in Redmond, WA. It specializes in developing innovative cancer treatments using its established drug development platforms, focusing on bi-specific, multi-specific antibodies, and antibody-drug conjugates (ADCs). SystImmune has several assets in various stages of clinical trials for solid tumor and hematologic indications. Alongside ongoing clinical trials, SystImmune has a robust preclinical pipeline of potential cancer therapeutics in the discovery or IND-enabling stages, representing cutting-edge biologics development.

Forward-Looking Statements
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SOURCE SystImmune, Inc.