HMBD-501 represents a potentially best-in-class HER3-ADC combining Hummingbird Bioscience’s data-rich, systems biology approach to rational antibody discovery with state-of-the-art bioconjugation technologies.

Why ADCs?

Antibody-drug conjugates (ADCs) are antibodies or antibody fragments linked to biologically active payloads.1 The antibody portion of the ADC binds to intended cells, delivering the attached payload selectively to tumor cells expressing specific target(s) and thereby avoiding impacting other non-cancerous cells. Internalization of the ADC by tumor cells leads to release of the cytotoxic payload.

Why a HER3-ADC?

Targeting HER3 with an anti-HER3 antibody has shown clinical potential in multiple settings, however not all HER3-expressing tumors may respond to inhibition of HER3 signaling. Where cell signaling pathways downstream of the HER3 receptor are dysregulated and driving tumor growth, a HER3-ADC may provide a more optimal therapeutic approach.

Why HMBD-501?

Designing a potentially best-in-class HER3-ADC starts with combining a best-in-class antibody with state-of-the-art ADC technologies. Earlier generation anti-HER3 antibodies do not target optimal epitopes on HER3 and demonstrate lower affinity binding, particularly in the presence of NRG1 ligand. In addition, earlier generation ADC technologies produced ADCs lacking homogeneity, stability, and hydrophilicity, resulting in a narrow therapeutic window and clinically observed toxicities.

Engineer with Precision

HMBD-501 was designed with the goal of being the best-in-class HER3-ADC. HMBD-501 is generated by our antibody discovery and engineering platform and key state-of-the-art ADC technologies that may enhance the efficacy and safety profile as compared to prior generation ADCs.

We have identified a potentially best-in-class ADC delivering a clinically validated payload with:

  • picomolar HER3 binding affinity
  • efficient internalization and trafficking properties,
  • an optimized Fc
  • a stable conjugation profile with increased hydrophilicity

With key proprietary technologies enabling a differentiated molecule, we believe HMBD-501 is poised to become a best-in-class HER3-ADC.