RNA · Atrium Therapeutics, Inc.

Twenty-five percent (25%) of the shares underlying this option shall vest and become exercisable on March 20, 2027, with the remaining shares vesting in thirty-six (36) substantially equal monthly installments each month thereafter, subject to the Reporting Person's continuous service to the Issuer on each such vesting date.

Represents an award of restricted stock units ("RSUs"). Each RSU represents a contingent right to receive one share of the Issuer's common stock. Twenty-five percent (25%) of the RSUs shall vest on March 20, 2027, with the remaining RSUs vesting in three (3) substantially equal yearly installments each year thereafter, subject to the Reporting Person's continuous service to the Issuer on each such vesting date.

Represents an award of restricted stock units ("RSUs"). Each RSU represents a contingent right to receive one share of the Issuer's common stock. Twenty-five percent (25%) of the RSUs shall vest on March 20, 2027, with the remaining RSUs vesting in three (3) substantially equal yearly installments each year thereafter, subject to the Reporting Person's continuous service to the Issuer on each such vesting date.

Represents an award of restricted stock units ("RSUs"). Each RSU represents a contingent right to receive one share of the Issuer's common stock. Twenty-five percent (25%) of the RSUs shall vest on March 20, 2027, with the remaining RSUs vesting in three (3) substantially equal yearly installments each year thereafter, subject to the Reporting Person's continuous service to the Issuer on each such vesting date.

Twenty-five percent (25%) of the shares underlying this option shall vest and become exercisable on March 20, 2027, with the remaining shares vesting in thirty-six (36) substantially equal monthly installments each month thereafter, subject to the Reporting Person's continuous service to the Issuer on each such vesting date.

Represents an award of restricted stock units ("RSUs"). Each RSU represents a contingent right to receive one share of the Issuer's common stock. Twenty-five percent (25%) of the RSUs shall vest on March 20, 2027, with the remaining RSUs vesting in three (3) substantially equal yearly installments each year thereafter, subject to the Reporting Person's continuous service to the Issuer on each such vesting date.

Represents an award of restricted stock units ("RSUs"). Each RSU represents a contingent right to receive one share of the Issuer's common stock. Twenty-five percent (25%) of the RSUs shall vest on March 20, 2027, with the remaining RSUs vesting in three (3) substantially equal yearly installments each year thereafter, subject to the Reporting Person's continuous service to the Issuer on each such vesting date.

Twenty-five percent (25%) of the shares underlying this option shall vest and become exercisable on March 20, 2027, with the remaining shares vesting in thirty-six (36) substantially equal monthly installments each month thereafter, subject to the Reporting Person's continuous service to the Issuer on each such vesting date.

Twenty-five percent (25%) of the shares underlying this option shall vest and become exercisable on March 20, 2027, with the remaining shares vesting in thirty-six (36) substantially equal monthly installments each month thereafter, subject to the Reporting Person's continuous service to the Issuer on each such vesting date.

Twenty-five percent (25%) of the shares underlying this option shall vest and become exercisable on March 20, 2027, with the remaining shares vesting in thirty-six (36) substantially equal monthly installments each month thereafter, subject to the Reporting Person's continuous service to the Issuer on each such vesting date.

Represents an award of restricted stock units ("RSUs"). Each RSU represents a contingent right to receive one share of the Issuer's common stock. Twenty-five percent (25%) of the RSUs shall vest on March 20, 2027, with the remaining RSUs vesting in three (3) substantially equal yearly installments each year thereafter, subject to the Reporting Person's continuous service to the Issuer on each such vesting date.

Twenty-five percent (25%) of the shares underlying this option shall vest and become exercisable on March 20, 2027, with the remaining shares vesting in thirty-six (36) substantially equal monthly installments each month thereafter, subject to the Reporting Person's continuous service to the Issuer on each such vesting date.

The options were granted on February 27, 2026 and the shares underlying the options vest in equal monthly installments over the three years following the grant date, subject to the Reporting Person's continuous service to the Issuer on each such vesting date.

The options were granted on February 27, 2026 and the shares underlying the options vest in equal monthly installments over the three years following the grant date, subject to the Reporting Person's continuous service to the Issuer on each such vesting date.

The options were granted on February 27, 2026 and the shares underlying the options vest in equal monthly installments over the three years following the grant date, subject to the Reporting Person's continuous service to the Issuer on each such vesting date.

The options were granted on February 27, 2026 and the shares underlying the options vest in equal monthly installments over the three years following the grant date, subject to the Reporting Person's continuous service to the Issuer on each such vesting date.

The options were granted on February 27, 2026 and the shares underlying the options vest in equal monthly installments over the three years following the grant date, subject to the Reporting Person's continuous service to the Issuer on each such vesting date.