ZNTL · Zentalis Pharmaceuticals, Inc.

The shares of common stock reported herein (the "Shares") are held directly by The Walters Group (the "TWG"). William T. Walters may be deemed to share voting and dispositive power with respect to the Shares. Susan B. Walters is the general partner and majority member of TWG and may be deemed to share voting and dispositive power with respect to the Shares. Each Reporting Person disclaims Section 16 beneficial ownership of the Shares reported herein except to the extent of its pecuniary interest therein, if any, and the inclusion of these Shares in this report shall not be deemed an admission of beneficial ownership of any of the reported Shares for purposes of Section 16 or any other purpose.

Represents restricted stock units granted pursuant to the Issuer's Non-Employee Director Compensation Program, each of which represents a contingent right to receive one share of common stock, and which will vest on the first to occur of (a) June 16, 2027 or (b) the next occurring annual meeting of the Issuer's stockholders, subject to the Reporting Person's continued service on the Issuer's Board of Directors through such vesting date.

Represents restricted stock units granted pursuant to the Issuer's Non-Employee Director Compensation Program, each of which represents a contingent right to receive one share of common stock, and which will vest on the first to occur of (a) June 16, 2027 or (b) the next occurring annual meeting of the Issuer's stockholders, subject to the Reporting Person's continued service on the Issuer's Board of Directors through such vesting date.

Represents restricted stock units granted pursuant to the Issuer's Non-Employee Director Compensation Program, each of which represents a contingent right to receive one share of common stock, and which will vest on the first to occur of (a) June 16, 2027 or (b) the next occurring annual meeting of the Issuer's stockholders, subject to the Reporting Person's continued service on the Issuer's Board of Directors through such vesting date.

Represents restricted stock units granted pursuant to the Issuer's Non-Employee Director Compensation Program, each of which represents a contingent right to receive one share of common stock, and which will vest on the first to occur of (a) June 16, 2027 or (b) the next occurring annual meeting of the Issuer's stockholders, subject to the Reporting Person's continued service on the Issuer's Board of Directors through such vesting date.

Represents restricted stock units granted pursuant to the Issuer's Non-Employee Director Compensation Program, each of which represents a contingent right to receive one share of common stock, and which will vest on the first to occur of (a) June 16, 2027 or (b) the next occurring annual meeting of the Issuer's stockholders, subject to the Reporting Person's continued service on the Issuer's Board of Directors through such vesting date.

The restricted stock units ("RSUs") were granted by the Issuer pursuant to the Issuer's Non-Employee Director Compensation Program. One third of the RSUs will vest on each of the first, second and third anniversaries of the grant date, subject to the reporting person's continued service with the Issuer on each vesting date.

This sale was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 18, 2025.

This sale was made automatically by the Issuer to cover tax withholding obligations in connection with the vesting and settlement of restricted stock units previously granted to the Reporting Person.

This sale was made automatically by the Issuer to cover tax withholding obligations in connection with the vesting and settlement of restricted stock units previously granted to the Reporting Person.

This sale was made automatically by the Issuer to cover tax withholding obligations in connection with the vesting and settlement of restricted stock units previously granted to the Reporting Person.

This sale was made automatically by the Issuer to cover tax withholding obligations in connection with the vesting and settlement of restricted stock units previously granted to the Reporting Person.

This sale was made automatically by the Issuer to cover tax withholding obligations in connection with the vesting and settlement of restricted stock units previously granted to the Reporting Person.

This sale was made automatically by the Issuer to cover tax withholding obligations in connection with the vesting and settlement of restricted stock units previously granted to the Reporting Person.

This sale was effected pursuant to a Rule 10b5-1 trading arrangement adopted by the Reporting Person.

This sale was made automatically by the Issuer to cover tax withholding obligations in connection with the vesting and settlement of restricted stock units previously granted to the Reporting Person.

The options will vest over four years in substantially equal monthly installments until the options are fully vested, subject to the Reporting Person's continued service with the Issuer.

The options will vest over four years in substantially equal monthly installments until the options are fully vested, subject to the Reporting Person's continued service with the Issuer.

The options will vest over four years in substantially equal monthly installments until the options are fully vested, subject to the Reporting Person's continued service with the Issuer.

The options will vest over four years in substantially equal monthly installments until the options are fully vested, subject to the Reporting Person's continued service with the Issuer.

The shares of common stock reported herein (the "Shares") are held directly by The Walters Group (the "TWG"). William T. Walters may be deemed to share voting and dispositive power with respect to the Shares. Susan B. Walters is the general partner and majority member of TWG and may be deemed to share voting and dispositive power with respect to the Shares. Each Reporting Person disclaims Section 16 beneficial ownership of the Shares reported herein except to the extent of its pecuniary interest therein, if any, and the inclusion of these Shares in this report shall not be deemed an admission of beneficial ownership of any of the reported Shares for purposes of Section 16 or any other purpose.

The securities reported herein are held by Matrix Capital Management Master Fund, LP (the "Matrix Fund"). Matrix Capital Management Company, LP (the "Investment Manager"), a Delaware limited partnership, is the investment advisor to the Matrix Fund. Mr. David E. Goel ("Mr. Goel", and together with the Investment Manager, the "Reporting Persons"), serves as the Managing General Partner of the Investment Manager.

The filing of this statement shall not be deemed an admission that either of the Reporting Persons is the beneficial owner of the securities reported herein for purposes of Section 16 of the Securities Act of 1934, as amended, or otherwise. Each of the Reporting Persons expressly disclaims beneficial ownership of the securities reported herein except to the extent of its or his pecuniary interest therein.

The options will vest over a four-year period as follows: 25% of the options will vest on October 1, 2026, with the remaining 75% vesting in substantially equal monthly installments thereafter until the options are fully vested, subject to the Reporting Person's continued service with the Issuer.

Represents restricted stock units granted pursuant to the Issuer's Non-Employee Director Compensation Program, each of which represents a contingent right to receive one share of common stock, and which will vest on the first to occur of (a) June 17, 2026 or (b) the next occurring annual meeting of the Issuer's stockholders, subject to the Reporting Person's continued service on the Issuer's Board of Directors through such vesting date.

Represents restricted stock units granted pursuant to the Issuer's Non-Employee Director Compensation Program, each of which represents a contingent right to receive one share of common stock, and which will vest on the first to occur of (a) June 17, 2026 or (b) the next occurring annual meeting of the Issuer's stockholders, subject to the Reporting Person's continued service on the Issuer's Board of Directors through such vesting date.

Represents restricted stock units granted pursuant to the Issuer's Non-Employee Director Compensation Program, each of which represents a contingent right to receive one share of common stock, and which will vest on the first to occur of (a) June 17, 2026 or (b) the next occurring annual meeting of the Issuer's stockholders, subject to the Reporting Person's continued service on the Issuer's Board of Directors through such vesting date.

Represents restricted stock units granted pursuant to the Issuer's Non-Employee Director Compensation Program, each of which represents a contingent right to receive one share of common stock, and which will vest on the first to occur of (a) June 17, 2026 or (b) the next occurring annual meeting of the Issuer's stockholders, subject to the Reporting Person's continued service on the Issuer's Board of Directors through such vesting date.

Represents restricted stock units granted pursuant to the Issuer's Non-Employee Director Compensation Program, each of which represents a contingent right to receive one share of common stock, and which will vest on the first to occur of (a) June 17, 2026 or (b) the next occurring annual meeting of the Issuer's stockholders, subject to the Reporting Person's continued service on the Issuer's Board of Directors through such vesting date.

The options will vest over four years in substantially equal monthly installments until the options are fully vested, subject to the Reporting Person's continued service with the Issuer.

This sale was made automatically by the Issuer to cover tax withholding obligations in connection with the vesting and settlement of restricted stock units previously granted to the Reporting Person.

The options will vest over four years in substantially equal monthly installments until the options are fully vested, subject to the Reporting Person's continued service with the Issuer.

Represents restricted stock units, each of which represent a contingent right to receive one share of common stock, and which will vest in substantially equal annual installments over a two year period following the grant date, subject to the Reporting Person's continued service with the Issuer.

Represents restricted stock units, each of which represent a contingent right to receive one share of common stock, and which will vest in substantially equal annual installments over a two year period following the grant date, subject to the Reporting Person's continued service with the Issuer.

This sale was made automatically by the Issuer to cover tax withholding obligations in connection with the vesting and settlement of restricted stock units previously granted to the Reporting Person.

Represents restricted stock units, each of which represent a contingent right to receive one share of common stock, and which will vest in substantially equal annual installments over a two year period following the grant date, subject to the Reporting Person's continued service with the Issuer.

Represents restricted stock units, each of which represent a contingent right to receive one share of common stock, and which will vest in substantially equal annual installments over a two year period following the grant date, subject to the Reporting Person's continued service with the Issuer.

Represents restricted stock units, each of which represent a contingent right to receive one share of common stock, and which will vest in substantially equal annual installments over a two year period following the grant date, subject to the Reporting Person's continued service with the Issuer.

The options will vest over four years in substantially equal monthly installments until the options are fully vested, subject to the Reporting Person's continued service with the Issuer.

The options will vest over four years in substantially equal monthly installments until the options are fully vested, subject to the Reporting Person's continued service with the Issuer.

The options will vest over four years in substantially equal monthly installments until the options are fully vested, subject to the Reporting Person's continued service with the Issuer.

This sale was made automatically by the Issuer to cover tax withholding obligations in connection with the vesting and settlement of restricted stock units previously granted to the Reporting Person.

This sale was made automatically by the Issuer to cover tax withholding obligations in connection with the vesting and settlement of restricted stock units previously granted to the Reporting Person.

The options will vest over a four-year period following the vesting commencement date of November 13, 2024, in substantially equal monthly installments until the options are fully vested, subject to the Reporting Person's continued service with the Issuer.

The options will vest over a four-year period as follows: 25% of the options will vest on November 13, 2025, with the remaining 75% vesting in substantially equal monthly installments thereafter until the options are fully vested, subject to the Reporting Person's continued service with the Issuer.

The restricted stock units ("RSUs") were granted by the Issuer pursuant to the Issuer's Non-Employee Director Compensation Program. One third of the RSUs will vest on each of the first, second and third anniversaries of the grant date, subject to the reporting person's continued service with the Issuer on each vesting date.