ERAS · Erasca, Inc. · Insider Trading

The reported option award was granted in connection with the Reporting Person's commencement of employment. Of the total option award, 21,480 shares were granted under the Issuer's 2021 Incentive Award Plan, with a portion intended to qualify as an incentive stock option under Section 422 of the Internal Revenue Code to the extent permitted by law. The remaining 1,278,520 shares were granted as a nonqualified stock option under the Issuer's 2026 Employment Inducement Incentive Award Plan.

The reported option award vests as follows: 25% of the shares subject to the option will vest on the first anniversary of the date of grant, and the remaining 75% of the shares will vest in 36 substantially equal monthly installments thereafter, subject to the Reporting Person's continued service with the Issuer through each applicable vesting date.

100% of the options to purchase shares vest on June 26, 2027, subject to the Reporting Person's continuous service to the Issuer on such vesting date.

100% of the options to purchase shares vest on June 26, 2027, subject to the Reporting Person's continuous service to the Issuer on such vesting date.

100% of the options to purchase shares vest on June 26, 2027, subject to the Reporting Person's continuous service to the Issuer on such vesting date.

100% of the options to purchase shares vest on June 26, 2027, subject to the Reporting Person's continuous service to the Issuer on such vesting date.

100% of the options to purchase shares vest on June 26, 2027, subject to the Reporting Person's continuous service to the Issuer on such vesting date.

100% of the options to purchase shares vest on June 26, 2027, subject to the Reporting Person's continuous service to the Issuer on such vesting date.

The exercise and sales reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan previously adopted by the Reporting Person on June 30, 2024.

1/48th of the shares subject to the option vest monthly, with vesting starting on February 1, 2024, subject to the Reporting Person's continuous service to the Issuer on each such vesting date.

The exercise and sales reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan previously adopted by the Reporting Person on June 30, 2024.

The exercise and sales reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan previously adopted by the Reporting Person on June 30, 2024.

This represents a weighted-average price. These shares were sold in multiple transactions at prices ranging from $16.11 to $16.58. The Reporting Person undertakes to provide the Issuer, any securityholder of the Issuer, or the Staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

The exercise and sales reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan previously adopted by the Reporting Person on June 30, 2024.

The exercise and sales reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan previously adopted by the Reporting Person on June 30, 2024.

This represents a weighted-average price. These shares were sold in multiple transactions at prices ranging from $15.00 to $15.10. The Reporting Person undertakes to provide the Issuer, any securityholder of the Issuer, or the Staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

1/48th of the shares subject to the option vest monthly on the 29th day of each month (or the last day of February), starting in February 2026, subject to the Reporting Person's continuous service to the issuer on each such vesting date.

1/48th of the shares subject to the option vest monthly on the 29th day of each month (or the last day of February), starting in February 2026, subject to the Reporting Person's continuous service to the issuer on each such vesting date.

1/48th of the shares subject to the option vest monthly on the 29th day of each month (or the last day of February), starting in February 2026, subject to the Reporting Person's continuous service to the issuer on each such vesting date.

1/48th of the shares subject to the option vest monthly on the 29th day of each month (or the last day of February), starting in February 2026, subject to the Reporting Person's continuous service to the issuer on each such vesting date.

1/48th of the shares subject to the option vest monthly on the 29th day of each month (or the last day of February), starting in February 2026, subject to the Reporting Person's continuous service to the issuer on each such vesting date.

The exercise and sales reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan previously adopted by the Reporting Person on June 30, 2024.

This represents a weighted-average price. These shares were sold in multiple transactions at prices ranging from $5.50 to $5.80. The Reporting Person undertakes to provide the Issuer, any securityholder of the Issuer, or the Staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

The exercise and sales reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan previously adopted by the Reporting Person on June 30, 2024.

At the election of the filing person the option grant was issued in lieu of the cash compensation payable to such person in 2026 in connection with each position on the issuer's board of directors and its committees for which such person is anticipated to serve in 2026.

The option will vest and become exercisable in monthly, cumulative 1/12 increments beginning one month from the date of grant, subject to such person continuing to serve on the issuer's board of directors through the applicable vesting date.

At the election of the filing person the option grant was issued in lieu of the cash compensation payable to such person in 2026 in connection with each position on the issuer's board of directors and its committees for which such person is anticipated to serve in 2026.

The option will vest and become exercisable in monthly, cumulative 1/12 increments beginning one month from the date of grant, subject to such person continuing to serve on the issuer's board of directors through the applicable vesting date.

At the election of the filing person the option grant was issued in lieu of the cash compensation payable to such person in 2026 in connection with each position on the issuer's board of directors and its committees for which such person is anticipated to serve in 2026.

The option will vest and become exercisable in monthly, cumulative 1/12 increments beginning one month from the date of grant, subject to such person continuing to serve on the issuer's board of directors through the applicable vesting date.

At the election of the filing person the option grant was issued in lieu of the cash compensation payable to such person in 2026 in connection with each position on the issuer's board of directors and its committees for which such person is anticipated to serve in 2026.

The option will vest and become exercisable in monthly, cumulative 1/12 increments beginning one month from the date of grant, subject to such person continuing to serve on the issuer's board of directors through the applicable vesting date.

At the election of the filing person the option grant was issued in lieu of the cash compensation payable to such person in 2026 in connection with each position on the issuer's board of directors and its committees for which such person is anticipated to serve in 2026.

The option will vest and become exercisable in monthly, cumulative 1/12 increments beginning one month from the date of grant, subject to such person continuing to serve on the issuer's board of directors through the applicable vesting date.

Shares purchased under the Company's 2021 Employee Stock Purchase Plan

The purchase price was calculated in accordance with the issuer's 2021 Employee Stock Purchase Plan.

The purchase price was calculated in accordance with the Issuer's 2021 Employee Stock Purchase Plan.

100% of the options to purchase shares vest on June 24, 2026, subject to the Reporting Person's continuous service to the Issuer on such vesting date.

100% of the options to purchase shares vest on June 24, 2026, subject to the Reporting Person's continuous service to the Issuer on such vesting date.

100% of the options to purchase shares vest on June 24, 2026, subject to the Reporting Person's continuous service to the Issuer on such vesting date.

100% of the options to purchase shares vest on June 24, 2026, subject to the Reporting Person's continuous service to the Issuer on such vesting date.

100% of the options to purchase shares vest on June 24, 2026, subject to the Reporting Person's continuous service to the Issuer on such vesting date.

100% of the options to purchase shares vest on June 24, 2026, subject to the Reporting Person's continuous service to the Issuer on such vesting date.

100% of the options to purchase shares vest on June 24, 2026, subject to the Reporting Person's continuous service to the Issuer on such vesting date.

The Reporting Person transferred 6,200 shares of common stock to a family trust for no consideration, for estate planning purposes. The Reporting Person holds all voting and dispositive power with respect to the securities held by the trust and remains the beneficial owner of such securities.

The Reporting Person transferred 6,200 shares of common stock to a family trust for no consideration, for estate planning purposes. The Reporting Person holds all voting and dispositive power with respect to the securities held by the trust and remains the beneficial owner of such securities.

The exercise and sales reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan previously adopted by the Reporting Person on June 30, 2024.

1/48th of the shares subject to the option vest monthly, with vesting starting on February 1, 2024, subject to the Reporting Person's continuous service to the Issuer on each such vesting date.

1/48th of the shares subject to the option vest monthly, with vesting starting on February 13, 2025, subject to the Reporting Person's continuous service to the issuer on each such vesting date.

1/48th of the shares subject to the option vest monthly, with vesting starting on February 1, 2025, subject to the Reporting Person's continuous service to the issuer on each such vesting date.

1/48th of the shares subject to the option vest monthly, with vesting starting on February 1, 2025, subject to the Reporting Person's continuous service to the issuer on each such vesting date.

1/48th of the shares subject to the option vest monthly, with vesting starting on February 1, 2025, subject to the Reporting Person's continuous service to the issuer on each such vesting date.

1/48th of the shares subject to the option vest monthly, with vesting starting on February 1, 2025, subject to the Reporting Person's continuous service to the issuer on each such vesting date.

The exercise and sales reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan previously adopted by the Reporting Person on June 30, 2024.

The shares subject to this option award are fully vested and exercisable as of the date hereof.

At the election of the filing person the option grant was issued in lieu of the cash compensation payable to such person in 2025 in connection with each position on the issuer's board of directors and its committees for which such person is anticipated to serve in 2025.

The option will vest and become exercisable in monthly, cumulative 1/12 increments beginning one month from the date of grant, subject to such person continuing to serve on the issuer's board of directors through the applicable vesting date.

At the election of the filing person the option grant was issued in lieu of the cash compensation payable to such person in 2025 in connection with each position on the issuer's board of directors and its committees for which such person is anticipated to serve in 2025.

The option will vest and become exercisable in monthly, cumulative 1/12 increments beginning one month from the date of grant, subject to such person continuing to serve on the issuer's board of directors through the applicable vesting date.

At the election of the filing person the option grant was issued in lieu of the cash compensation payable to such person in 2025 in connection with each position on the issuer's board of directors and its committees for which such person is anticipated to serve in 2025.

The option will vest and become exercisable in monthly, cumulative 1/12 increments beginning one month from the date of grant, subject to such person continuing to serve on the issuer's board of directors through the applicable vesting date.

At the election of the filing person the option grant was issued in lieu of the cash compensation payable to such person in 2025 in connection with each position on the issuer's board of directors and its committees for which such person is anticipated to serve in 2025.

The option will vest and become exercisable in monthly, cumulative 1/12 increments beginning one month from the date of grant, subject to such person continuing to serve on the issuer's board of directors through the applicable vesting date.

Shares purchased under the Company's 2021 Employee Stock Purchase Plan

The purchase price was calculated in accordance with the issuer's 2021 Employee Stock Purchase Plan.

Reflects all transactions reported under this report.

Shares purchased under the Company's 2021 Employee Stock Purchase Plan

The purchase price was calculated in accordance with the issuer's 2021 Employee Stock Purchase Plan.

Reflects all transactions reported under this report.

100% of the options to purchase shares vest on June 20, 2025, subject to the Reporting Person's continuous service to the Issuer on such vesting date.

100% of the options to purchase shares vest on June 20, 2025, subject to the Reporting Person's continuous service to the Issuer on such vesting date.