SparX to Present Phase 1 Clinical Updates of SPX-303, a Dual Checkpoint Bispecific Antibody, at Two Events During AACR 2025

CHICAGO, April 18, 2025 /PRNewswire/ -- SparX Biopharmaceutical Corp. announced today that it will present clinical updates on its lead asset, SPX-303, a first-in-class anti-LILRB2/PD-L1 bispecific antibody, during the Trial-in-Progress poster session at the 2025 American Association for Cancer Research (AACR) Annual Meeting on April 28, from 2:00 PM to 5:00 PM. The presentation marks the one-year anniversary of the first patient dosing of this novel bispecific antibody in its ongoing Phase 1 clinical trial.

A more comprehensive overview of SPX-303's dual mechanism, which targets both myeloid and T-cell immune checkpoints, will be featured at a Satellite Symposium themed "Harnessing Super Immunotherapy and ADCs to Redefine the Standard of Care." Co-hosted by the University of Illinois at Chicago Cancer Center and Yao Yuan—Academy for Pharma Innovation, the symposium will convene expert clinicians, academic investigators, and industry leaders to discuss how next-generation immuno-oncology, known as "Super IO," can be synergized with antibody-drug conjugates (ADCs). This innovative approach combines the tumor-targeting precision of ADCs with the immune-activating power of checkpoint inhibitors, aiming to deliver deeper and more durable anti-tumor responses.

SPX-303, a first-in-class bispecific antibody targeting LILRB2 and PD-L1, is currently enrolling patients with resistant or refractory solid tumors at a dose level of 20 mg/kg. "This innovative program represents a significant advancement in macrophage checkpoint blockade and T cell co-engagement strategies," said Dr. Gui-Dong Zhu, CEO of SparX. "It holds promise as a potential next-generation immuno-oncology therapy—or 'Super IO' booster—for patients with limited treatment options."

The SPX-303 poster will be presented at Poster #CT116-11 in the Phase I Clinical Trials in Progress session at McCormick Place, Chicago, on April 28, from 2:00 to 5:00 PM. The Satellite Symposium will be held at the Trump International Hotel & Tower^® Chicago (401 N Wabash Ave, Chicago, IL 60611). SparX welcomes attendees to visit its exhibition booth during the symposium and strongly encourages early registration via the [registration portal] to secure a seat.

About SPX-303

SPX-303 is a first-in-its-class bispecific antibody therapy designed to simultaneously inhibit LILRB2 and PD-L1, two critical immune checkpoint proteins often hijacked by cancer cells. The program represents a novel immunotherapy approach aimed at activating both myeloid and lymphoid immune responses.

About SparX Biopharmaceutical Corp.

SparX Biopharmaceutical Corp. is a research-driven, development-stage biopharmaceutical company dedicated to advancing transformative nanobody-based therapeutics through innovation, global collaboration, and scientific leadership—bringing next-generation treatments to patients worldwide. Leveraging advanced platforms such as SAILING^™ and its proprietary Nab2 bi-ADC technology, SparX integrates AI-enabled discovery with robust in-house cGMP manufacturing capabilities to drive innovation from target identification through clinical development. With integrated antibody discovery systems and state-of-the-art facilities in Chicago, SparX is well-positioned to support clinical and commercial-scale production, enabling its evolution into a fully integrated, independent biopharmaceutical company.

For more information about the SPX-303 study, please visit: www.clinicaltrials.gov (Identifier: NCT06259552)

SOURCE SparX Biopharmaceutical