Veraxa Advances Bispecific ADC Candidate VXA-222 Following OmniAb Discovery Milestone

Veraxa Biotech AG announced the advancement of VXA-222, its bispecific antibody-drug conjugate (bsADC) program, after reaching a key technical milestone in its collaboration with OmniAb, Inc.¹ OmniAb has successfully completed its antibody discovery work under the partnership, allowing the program to move into its next development phase.¹ The collaboration, established in May 2025, combines OmniAb's transgenic antibody discovery platform with Veraxa’s proprietary ADC linker and conjugation technology.¹

Christoph Erkel, PhD, chief scientific officer of Veraxa, said, "We are pleased to announce this important achievement and the advancement of this program from our alliance with OmniAb for the development of a novel AND-gated bsADC utilizing our conjugation and linker technology. This successful partnership has united two highly complementary technologies to establish a new therapeutic candidate in VXA-222, representing a powerful opportunity for a best-in-class bispecific ADC to address solid tumor indications with high unmet medical need. We look forward to advancing this program and acknowledge OmniAb's partnership and contributions in delivering a diverse set of highly promising antibodies."¹

How does VXA-222's "AND-gate" design work?

VXA-222 is designed to target two distinct tumor antigens simultaneously within a single molecule using what the companies describe as an "AND-gate" approach, intended to improve precision in treating solid tumors compared to conventional single-target ADCs.¹

Under the collaboration, OmniAb supplied its transgenic antibody discovery technology to source the human antibody leads behind VXA-222.² OmniAb's platform uses genetically engineered animals, including rats, mice, and chickens, modified to produce antibodies with fully human sequences rather than the murine sequences that earlier antibody discovery methods relied on, reducing the need for downstream humanization steps.² For bispecific programs specifically, OmniAb offers OmniFlic, a transgenic rat engineered to express a single fixed light chain, a design intended to solve the "chain pairing problem" that has historically complicated bispecific antibody discovery, since a standard antibody-producing animal generates many possible combinations of heavy and light chains, only one of which yields the desired bispecific pairing.³

How does this fit into Veraxa broader strategy?

This dual-antigen strategy is one of several approaches companies are pursuing to combine bispecific antibody engineering with ADC payload delivery. Novartis-backed Sidewinder Therapeutics, for example, is developing its own bispecific ADC platform aimed at improving tumor targeting and reducing off-target toxicity in solid tumors.⁴

The VXA-222 program builds on the May 2025 co-discovery alliance between Veraxa and OmniAb, under which Veraxa contributes its ADC linker technology and conjugation expertise while OmniAb provides antibody discovery capabilities generating a diverse set of human antibody leads.¹ Veraxa has pursued a similar structure in other partnerships, including Biocytogen's recent global collaboration with Whitehawk Therapeutics, which likewise combines bispecific antibody discovery with ADC linker-payload technology.⁵

Veraxa, which originated as a spinout from research at the European Molecular Biology Laboratory (EMBL), became a publicly traded company on the Nasdaq under the ticker VRXA in June 2026, following a business combination with special purpose acquisition company Voyager Acquisition Corp.⁶ The company's broader pipeline centers on its proprietary BiTAC platform, designed to conditionally activate therapeutic activity specifically at tumor sites, an approach intended to improve target specificity and reduce off-tumor toxicity across Veraxa antibody-drug conjugate and T-cell engager programs.⁷ At the time of the original May 2025 OmniAb alliance, Veraxa characterized it as the company's second major partnership within six months, following an earlier radiopharmaceutical collaboration.²

What happens next?

With OmniAb's discovery work now complete, Veraxa’s next steps involve advancing VXA-222 through further development toward clinical candidacy. The companies did not specify a timeline for reaching an investigational new drug filing or entering clinical trials in this announcement.

References

1. Veraxa Biotech Announces Advancement of Novel Bispecific Antibody Drug Conjugate Program VXA-222 from Joint Discovery Collaboration with OmniAb. (2026 Jul 27). GlobeNewswire. https://www.globenewswire.com/news-release/2026/07/27/3333374/0/en/veraxa-biotech-announces-advancement-of-novel-bispecific-antibody-drug-conjugate-program-vxa-222-from-joint-discovery-collaboration-with-omniab.html
2. Veraxa Biotech Enters Co-discovery Alliance with OmniAb for a Novel Bispecific Antibody Drug Conjugate Program. (2025 May 5). GlobeNewswire. https://www.globenewswire.com/news-release/2025/05/05/3074351/0/en/veraxa-biotech-enters-co-discovery-alliance-with-omniab-for-a-novel-bispecific-antibody-drug-conjugate-program.html
3. Transgenic Antibody Discovery Technology Platform. https://www.omniab.com/technology/transgenic-platforms/
4. Marisol F. (2026 Apr 8). Sidewinder Targets Solid Tumors with Bispecific ADCs on Novartis-Backed Funding. BioPharm International. https://www.biopharminternational.com/view/sidewinder-targets-solid-tumors-with-bispecific-adcs-on-novartis-backed-funding
5. Schoenthaler E. (2026 Jul 7). Biocytogen and Whitehawk Therapeutics Partner to Develop Bispecific Antibody-Drug Conjugates Using Complementary Platform Technologies. BioPharm International. https://www.biopharminternational.com/view/biocytogen-and-whitehawk-therapeutics-partner-to-develop-bispecific-antibody-drug-conjugates-using-complementary-platform-technologies
6. Heidelberg-based Veraxa Ventures onto Nasdaq in Turbulent Market Environment. (2026 Jun 11). European Biotechnology Magazine. https://european-biotechnology.com/latest-news/heidelberg-based-veraxa-ventures-onto-nasdaq-in-turbulent-market-environment/
7. MissionIR. Veraxa Biotech AG.https://www.missionir.com/relationships/veraxa-biotech-ag/