Organization	12 Months Ended
Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	1. Organization Description of the Business IDEAYA Biosciences, Inc. (the “Company”) is a synthetic lethality-focused precision medicine oncology company committed to the discovery and development of targeted therapeutics for patient populations selected using molecular diagnostics. The Company is headquartered in South San Francisco, California and was incorporated in the State of Delaware in June 2015. To date, the Company has been primarily engaged in business planning, research, development, recruiting and raising capital. Follow-On Offering On September 19, 2022, we completed an underwritten public offering of 8,761,905 shares of our common stock at an offering price to the public of $10.50 per share, including 1,142,857 shares of common stock upon the exercise in full of the overallotment option by the underwriters, pursuant to which we received aggregate net proceeds of $86.1 million, after deducting underwriting discounts and commissions and other offering expenses. On April 27, 2023, the Company completed an underwritten public follow-on offering. The offering consisted of 8,858,121 shares of our common stock at an offering price to the public of $18.50 per share, including 1,418,920 shares of common stock upon the exercise in full of the overallotment option by the underwriters, as well as pre-funded warrants to purchase 2,020,270 shares of common stock at a public offering price of $18.4999 per underlying share, in each case before underwriting discounts and commissions. Pursuant to the offering, we received aggregate gross proceeds of approximately $201.3 million, before deducting underwriting discounts and commissions and other offering expenses, resulting in net proceeds of approximately $188.7 million, after deducting underwriting discounts and commissions and other offering expenses. On October 27, 2023, the Company completed a further underwritten public follow-on offering. The offering consisted of 5,797,872 shares of our common stock at an offering price to the public of $23.50 per share, including 797,872 shares of common stock upon the exercise in full of the overallotment option by the underwriters, as well as pre-funded warrants to purchase 319,150 shares of common stock at a public offering price of $23.4999 per underlying share, in each case before underwriting discounts and commissions. Pursuant to the offering, we received aggregate gross proceeds of approximately $143.7 million, before deducting underwriting discounts and commissions and other offering expenses, resulting in net proceeds of approximately $134.6 million, after deducting underwriting discounts and commissions and other offering expenses. At-the-Market Offering Our Registration Statement on Form S-3, which was filed under the Securities Act, and became effective as of June 10, 2020, lapsed in June 2023. The January 2021 Sales Agreement was automatically terminated concurrently therewith. As of the termination date of the January 2021 Sales Agreement, approximately $61.8 million of common stock remained available to be sold under the at-the-market facility associated therewith. On June 26, 2023, we filed a new Registration Statement on Form S-3 (File No. 333- 272936) under the Securities Act as an automatic shelf registration statement as a “well-known seasoned issuer”, as defined in Rule 405 under the Securities Act. On June 26, 2023, we also entered into a new Open Market Sales Agreement, or June 2023 Sales Agreement, with Jefferies LLC (“Jefferies”) relating to an at-the-market offering program under which we may offer and sell, from time to time at our sole discretion, shares of our common stock, par value $0.0001 per share, having aggregate gross proceeds of up to $250.0 million through Jefferies as sales agent. During the year ended December 31, 2023, we sold an aggregate of 1,188,705 shares of our common stock through at-the-market offerings for aggregate net proceeds of $28.6 million, after deducting underwriting discounts and commissions and other offering expenses, at a weighted average sales price of approximately $25.30 per share under the at-the-market offering pursuant to the January 2021 Sales Agreement and June 2023 Sales Agreement with Jefferies as sales agent. As of December 31, 2023, approximately $222.5 million of common stock remained available to be sold under the June 2023 Sales Agreement with Jefferies as sales agent. We may cancel our at-the-market program at any time upon written notice, pursuant to its terms. Liquidity The Company has incurred significant losses and negative cash flows from operations in all periods since inception and had an accumulated deficit of $348.4 million as of December 31, 2023. The Company has historically financed its operations primarily through the sale of convertible notes, redeemable convertible preferred stock and common stock, pre-funded warrants, and payments received from its collaboration arrangement. To date, none of the Company’s product candidates have been approved for sale, and the Company has not generated any revenue from commercial products since inception. Management expects operating losses to continue and increase for the foreseeable future, as the Company progresses into clinical development activities for its lead product candidates. The Company’s prospects are subject to risks, expenses and uncertainties frequently encountered by companies in the biotechnology industry as discussed under Risks and Uncertainties in Note 2. While the Company has been able to raise multiple rounds of financing, there can be no assurance that in the event the Company requires additional financing, such financing will be available on terms which are favorable or at all. Failure to generate sufficient cash flows from operations, raise additional capital or reduce certain discretionary spending would have a material adverse effect on the Company’s ability to achieve its intended business objectives. As of December 31, 2023, the Company had cash, cash equivalents and marketable securities of $632.6 million. Management believes that the Company’s current cash, cash equivalents and marketable securities will be sufficient to fund its planned operations for at least 12 months from the date of the issuance of these financial statements.

Organization

12 Months Ended

Dec. 31, 2023

Organization, Consolidation and Presentation of Financial Statements [Abstract]

1. Organization

Description of the Business

IDEAYA Biosciences, Inc. (the “Company”) is a synthetic lethality-focused precision medicine oncology company committed to the discovery and development of targeted therapeutics for patient populations selected using molecular diagnostics. The Company is headquartered in South San Francisco, California and was incorporated in the State of Delaware in June 2015. To date, the Company has been primarily engaged in business planning, research, development, recruiting and raising capital.

Follow-On Offering

On September 19, 2022, we completed an underwritten public offering of 8,761,905 shares of our common stock at an offering price to the public of $10.50 per share, including 1,142,857 shares of common stock upon the exercise in full of the overallotment option by the underwriters, pursuant to which we received aggregate net proceeds of $86.1 million, after deducting underwriting discounts and commissions and other offering expenses.

On April 27, 2023, the Company completed an underwritten public follow-on offering. The offering consisted of 8,858,121 shares of our common stock at an offering price to the public of $18.50 per share, including 1,418,920 shares of common stock upon the exercise in full of the overallotment option by the underwriters, as well as pre-funded warrants to purchase 2,020,270 shares of common stock at a public offering price of $18.4999 per underlying share, in each case before underwriting discounts and commissions. Pursuant to the offering, we received aggregate gross proceeds of approximately $201.3 million, before deducting underwriting discounts and commissions and other offering expenses, resulting in net proceeds of approximately $188.7 million, after deducting underwriting discounts and commissions and other offering expenses.

On October 27, 2023, the Company completed a further underwritten public follow-on offering. The offering consisted of 5,797,872 shares of our common stock at an offering price to the public of $23.50 per share, including 797,872 shares of common stock upon the exercise in full of the overallotment option by the underwriters, as well as pre-funded warrants to purchase 319,150 shares of common stock at a public offering price of $23.4999 per underlying share, in each case before underwriting discounts and commissions. Pursuant to the offering, we received aggregate gross proceeds of approximately $143.7 million, before deducting underwriting discounts and commissions and other offering expenses, resulting in net proceeds of approximately $134.6 million, after deducting underwriting discounts and commissions and other offering expenses.

At-the-Market Offering

Our Registration Statement on Form S-3, which was filed under the Securities Act, and became effective as of June 10, 2020, lapsed in June 2023. The January 2021 Sales Agreement was automatically terminated concurrently therewith. As of the termination date of the January 2021 Sales Agreement, approximately $61.8 million of common stock remained available to be sold under the at-the-market facility associated therewith.

On June 26, 2023, we filed a new Registration Statement on Form S-3 (File No. 333- 272936) under the Securities Act as an automatic shelf registration statement as a “well-known seasoned issuer”, as defined in Rule 405 under the Securities Act. On June 26, 2023, we also entered into a new Open Market Sales Agreement, or June 2023 Sales Agreement, with Jefferies LLC (“Jefferies”) relating to an at-the-market offering program under which we may offer and sell, from time to time at our sole discretion, shares of our common stock, par value $0.0001 per share, having aggregate gross proceeds of up to $250.0 million through Jefferies as sales agent.

During the year ended December 31, 2023, we sold an aggregate of 1,188,705 shares of our common stock through at-the-market offerings for aggregate net proceeds of $28.6 million, after deducting underwriting discounts and commissions and other offering expenses, at a weighted average sales price of approximately $25.30 per share under the at-the-market offering pursuant to the January 2021 Sales Agreement and June 2023 Sales Agreement with Jefferies as sales agent. As of December 31, 2023, approximately $222.5 million of common stock remained available to be sold under the June 2023 Sales Agreement with Jefferies as sales agent.

We may cancel our at-the-market program at any time upon written notice, pursuant to its terms.

Liquidity

The Company has incurred significant losses and negative cash flows from operations in all periods since inception and had an accumulated deficit of $348.4 million as of December 31, 2023.

The Company has historically financed its operations primarily through the sale of convertible notes, redeemable convertible preferred stock and common stock, pre-funded warrants, and payments received from its collaboration arrangement.

To date, none of the Company’s product candidates have been approved for sale, and the Company has not generated any revenue from commercial products since inception. Management expects operating losses to continue and increase for the foreseeable future, as the Company progresses into clinical development activities for its lead product candidates. The Company’s prospects are subject to risks, expenses and uncertainties frequently encountered by companies in the biotechnology industry as discussed under Risks and Uncertainties in Note 2. While the Company has been able to raise multiple rounds of financing, there can be no assurance that in the event the Company requires additional financing, such financing will be available on terms which are favorable or at all. Failure to generate sufficient cash flows from operations, raise additional capital or reduce certain discretionary spending would have a material adverse effect on the Company’s ability to achieve its intended business objectives.

As of December 31, 2023, the Company had cash, cash equivalents and marketable securities of $632.6 million. Management believes that the Company’s current cash, cash equivalents and marketable securities will be sufficient to fund its planned operations for at least 12 months from the date of the issuance of these financial statements.