VERAXA Biotech (NASDAQ: VRXA) said Monday that VXA-222, its bispecific antibody-drug conjugate (bsADC) program, has reached a key technical milestone under the company’s collaboration with OmniAb. The achievement enables the program to advance into its next phase and moves the potential therapy closer to clinical development.

VXA-222 is being developed to target two tumor antigens at the same time through an “AND-gate” approach intended to improve precision in the treatment of solid tumors. The bispecific mechanism is designed so the drug activates only when both targets are present, a feature that could potentially reduce off-target effects associated with traditional antibody-drug conjugates.

The milestone is technical rather than clinical, meaning the program still has to move through additional preclinical work before any human testing. For antibody-drug conjugates, development typically depends on demonstrating that the antibody, linker and payload can work together with sufficient tumor selectivity, stability and tolerability to support further study.

The collaboration between VERAXA and OmniAb was launched in May 2025. It combines OmniAb’s antibody discovery technologies, including the OmniClic platform, with VERAXA’s proprietary linker technology and conjugation expertise. Under the agreement, VERAXA has exclusive rights to develop and commercialize products resulting from the collaboration, while OmniAb is entitled to receive a share of specified revenue from resulting products.

“Reaching this milestone demonstrates the strength of our partnership with OmniAb and the potential of our bispecific ADC platform,” a VERAXA spokesperson said. “VXA-222 represents a novel approach to targeting solid tumors, and we are excited to advance it toward the clinic.”

VERAXA was founded on scientific breakthroughs from the European Molecular Biology Laboratory (EMBL). The company focuses on next-generation antibody-based therapeutics, including bispecific T cell engagers and bispecific ADCs. Its pipeline is based on its BiTAC format and quality-by-design principles.

The VXA-222 advancement comes as bispecific ADCs continue to draw attention as a possible way to improve the therapeutic index of cancer treatments. By engaging two targets, these molecules may enhance tumor specificity and reduce damage to healthy tissue. The AND-gate logic used in VXA-222 is designed to add another layer of control by requiring both antigens to be present for the drug to be active.

VERAXA is moving the program toward preclinical and clinical studies. The company said forward-looking statements in the announcement are subject to risks and uncertainties, including those described in VERAXA’s SEC filings. VERAXA said it undertakes no obligation to update the information unless required by law.