Elevation Oncology to Present Preclinical Data for EO-1022 at the American Association for Cancer Research (AACR) Annual Meeting 2025

-- Abstract accepted for late-breaking poster presentation –

-- EO-1022 is a potentially differentiated HER3 ADC being developed for the treatment of solid tumors, including breast and non-small cell lung cancers --

-- On-track to file an Investigational New Drug (IND) application in 2026 –

BOSTON, March 25, 2025 — Elevation Oncology, Inc. (Nasdaq: ELEV), an innovative oncology company focused on the discovery and development of selective cancer therapies to treat patients across a range of solid tumors with significant unmet medical needs, today announced that it will present preclinical data for its novel HER3 ADC, EO-1022, in a late-breaking poster presentation at the American Association for Cancer Research (AACR) Annual Meeting 2025, being held April 25-30 in Chicago, Illinois.

EO-1022 is an antibody drug conjugate (ADC) containing seribantumab, a fully human IgG2 anti-HER3 monoclonal antibody (mAb), which is site-specifically conjugated at glycan to the monomethyl auristatin E (MMAE) payload with a drug-to-antibody ratio (DAR) of 4. Elevation Oncology designed EO-1022, leveraging the advanced site-specific conjugation technology platform licensed from Synaffix B.V. Elevation Oncology is developing EO-1022 for the treatment of solid tumors that express HER3, including breast cancer and non-small cell lung cancer, and expects to file an IND application in 2026.

"We are eager to share the first preclinical data for EO-1022 at the AACR Annual Meeting," said Joseph Ferra, President and Chief Executive Officer of Elevation Oncology. "With EO-1022, we are combining the most advanced site-specific conjugation technology platform with the clinically validated MMAE payload, which is widely used across ADC programs but has yet to be introduced into a HER3-targeting ADC in the clinic. We believe this unique combination will enable us to provide a new treatment option to patients with HER3-expressing solid tumors, including those who are refractory to other HER3-targeting agents in development. We look forward to advancing EO-1022 into clinical development next year."

Details of the poster presentation at AACR 2025 are as follows:

Title: Preclinical discovery and characterization of EO-1022, a site-specific glycan-conjugated anti-HER3 vc-MMAE ADC for treating solid tumors

• Abstract Presentation Number: LB004
• Session Title: Late-Breaking Research: Experimental and Molecular Therapeutics 1
• Session Date and Time: Sunday, April 27, from 2 p.m. to 5 p.m. CT (3 p.m. to 6 p.m. ET)
• Location: Poster Section 50

The late-breaking abstract will become available on the AACR website beginning at 12:00 noon CT (1:00 p.m. ET) on April 25, 2025, and published in an online-only supplement to Cancer Research.

About EO-1022

Elevation Oncology is developing EO-1022, a potentially differentiated HER3 ADC for the treatment of HER3-expressing solid tumors, including breast cancer and non-small cell lung cancer. EO-1022 consists of seribantumab, a fully human IgG2 anti-HER3 antibody, site-specifically conjugated at glycan to the MMAE payload with a DAR of 4. It leverages seribantumab's desirable internalization properties and advanced site-specific ADC technology which makes possible the use of the potent cytotoxic MMAE payload. Elevation Oncology expects to file an IND application in 2026.

About Elevation Oncology, Inc.

Elevation Oncology is an innovative oncology company focused on the discovery and development of selective cancer therapies to treat patients across a range of solid tumors with significant unmet medical needs. We are leveraging our ADC expertise to advance EO-1022, a HER3 ADC for the treatment of patients with HER3-expressing solid tumors. EO-1022 is currently progressing through preclinical development, with an investigational new drug (IND) application expected in 2026. For more information, visit www.ElevationOncology.com.

Elevation Oncology Investor and Media Contact

Gracie Tong Senior Director, Investor Relations and Corporate Communications [email protected]