Company: WHWK
Filing Date: 2025-04-28
Form Type: DEFA14A
Source: 0001628280-25-020317
Chunk: 0

Company: Whitehawk Therapeutics, Inc.
Filing Date: 2025-04-28
Form: DEFA14A
Chunk 0
---
### UNITED STATES

### SECURITIES AND EXCHANGE COMMISSION

#### Washington, D.C. 20549

#### SCHEDULE 14A

#### Proxy Statement Pursuant to Section 14(a) of

#### the Securities Exchange Act of 1934
Filed by the Registrant x

Filed by a party other than the Registrant o

Check the appropriate box:

| o |     | Preliminary Proxy Statement                                                     |
| o |     | Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) |
| o |     | Definitive Proxy Statement                                                      |
| x |     | Definitive Additional Materials                                                 |
| o |     | Soliciting Material under §240.14a-12                                           |

#### WHITEHAWK THERAPEUTICS, INC.
<div align='center'>(Name of Registrant as Specified In Its Charter)

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)</div>

Payment of Filing Fee (Check all boxes that apply):

| x |     | No fee required.                                                                                     |
| o |     | Fee paid previously with preliminary materials.                                                      |
| o |     | Fee computed on table in exhibit required by Item 25(b) per Exchange Act Rules 14a-6(i)(1) and 0-11. |