• Nominated development candidate IDE251, a potential first-in-class KAT6/7 inhibitor
• IDE251 is targeted to be evaluated in breast and NSCLC with 8p11 amplification, and in the setting of lineage addiction. 8p11 amplification prevalence is projected to be ~15% in breast cancer and ~17.5% in squamous NSCLC
• Demonstrated robust and durable monotherapy anti-tumor activity in multiple biomarker positive breast and lung xenografts models
• Targeting IND submission for IDE251 in 2025

SOUTH SAN FRANCISCO, Calif., Dec. 16, 2024 /PRNewswire/ -- IDEAYA Biosciences, Inc. (Nasdaq: IDYA), a precision medicine oncology company committed to the discovery and development of targeted therapeutics, today announced the development candidate nomination of IDE251, a potential first-in-class KAT6/7 dual inhibitor.

"We are pleased to announce the nomination of IDE251 as our third development candidate this quarter and 8th development candidate in our precision medicine oncology pipeline. IDE251 has a potential first-in-class product profile and selectively inhibits two epigenetic modulators, KAT6 and KAT7, and based on the preclinical profile we believe there is an opportunity for an enriched response in 8p11 amplified cancers, which occur in 15% of breast cancers patients and in up to 17.5% in squamous NSCLC," said Yujiro S. Hata, President and Chief Executive Officer of IDEAYA Biosciences.

"IDE251 is a promising potential first-in-class molecule designed to selectively target both KAT6 and KAT7 while sparing other structurally similar KAT family members. KAT6 and KAT7 are mechanistically intertwined epigenetic modulators of cell identity and lineage commitment programs corrupted by oncogenic transformation. Dual KAT6/7 inhibition with IDE251 delivers robust and durable anti-tumor activity, superior to KAT6 inhibition alone, in preclinical tumor models with 8p11 amplifications as well as in biomarker selected indications dependent upon lineage-specific transcription factor activity. IND-enabling studies are progressing as planned and we are targeting to bring this program to the clinic next year," commented Michael White, Ph.D., Chief Scientific Officer, IDEAYA Biosciences.

IDE251 is an equipotent, highly selective, small molecule dual inhibitor of the lysine acetyltransferase (KAT) 6 and 7, both of which have been shown to support cancer cell survival. IND-enabling studies to support the potential clinical evaluation of IDE251 monotherapy in patients with breast and lung cancers with 8p11 amplification are ongoing, as well as additional opportunities in the setting of lineage addiction. Based on IDEAYA's biomarker evaluation, 8p11 amplification prevalence is projected to be approximately 15% in breast cancer and 17.5% in squamous NSCLC.

IDEAYA is targeting an Investigational New Drug (IND) submission to the U.S. Food and Drug Administration (FDA) in 2025 for IDE251, subject to satisfactory completion of ongoing preclinical and IND-enabling studies.

About IDEAYA Biosciences
IDEAYA is a precision medicine oncology company committed to the discovery and development of targeted therapeutics for patient populations selected using molecular diagnostics. IDEAYA's approach integrates capabilities in identifying and validating translational biomarkers with drug discovery to select patient populations most likely to benefit from its targeted therapies. IDEAYA is applying its research and drug discovery capabilities to synthetic lethality – which represents an emerging class of precision medicine targets.

Forward-Looking Statements
This press release contains forward-looking statements, including, but not limited to, statements related to (i) the development progress and IND submission timelines of IDE251, a KAT 6/7 dual inhibitor and (ii) the potential antitumor activity and therapeutic benefit of IDE251. Such forward-looking statements involve substantial risks and uncertainties that could cause IDEAYA's preclinical and clinical development programs, future results, performance or achievements to differ significantly from those expressed or implied by the forward-looking statements. Such risks and uncertainties include, among others, the uncertainties inherent in the drug development process, including IDEAYA's programs' early stage of development, the process of designing and conducting preclinical and clinical trials, the regulatory approval processes, the timing of regulatory filings, the challenges associated with manufacturing drug products, IDEAYA's ability to successfully establish, protect and defend its intellectual property, and other matters that could affect the sufficiency of existing cash to fund operations. IDEAYA undertakes no obligation to update or revise any forward-looking statements. For a further description of the risks and uncertainties that could cause actual results to differ from those expressed in these forward-looking statements, as well as risks relating to the business of IDEAYA in general, see IDEAYA's Annual Report on Form 10-K dated February 20, 2024 and any current and periodic reports filed with the U.S. Securities and Exchange Commission.

Investor and Media Contact
IDEAYA Biosciences
Andres Ruiz Briseno
SVP, Head of Finance and Investor Relations
[email protected]

SOURCE IDEAYA Biosciences, Inc.