Company: WHWK
Filing Date: 2025-01-21
Form Type: PREM14A
Source: 0001193125-25-009599
Chunk: 292

Company: Whitehawk Therapeutics, Inc.
Filing Date: 2025-01-21
Form: PREM14A
Chunk 292
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Figure 5- Waterfall plot of Maximum Reduction in Target Lesions, Two-year Follow-up (Wagner et al., JCO 2021)

*A patient with unconfirmed PR is considered having SD as best response (trial required confirmation of responses per
RECIST v1.1). Additionally, a patient with a complete response of target tumor reduction had a PR as best response because of unresolved nontarget lesions at the 2-year data cutoff (Wagner et al, JCO 2021);
however, this patient later achieved a confirmed complete response (FYARRO Prescribing Information).

Treatment-related adverse events (“TRAE”)
were consistent with those reported for other mTOR inhibitors. The most common hematologic events were anemia and thrombocytopenia, and the most common nonhematologic events were mucositis, rash and fatigue. The details are provided in Table 1
below. There were no grade 4 or 5 TRAEs. Noninfectious pneumonitis occurred in 6/34 (18%) patients and all were low grade (G1/G2). Patient discontinuation due to adverse events occurred on 3/34 (9%) patients (one grade 2 anemia and one grade 1
cystitis). Dose reductions occurred in 12/34 (35%) patients; 11 patients had a one dose reduction from 100 mg/m2 to 75 mg/m2 and 2 patients had two dose reductions to 56 mg/m2.

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Table 2- Treatment-related adverse events

| TRAE                    |     | Any Grade ≥ 25%, No. (%) |    |      |     | Grade 3, No. (%) |
| Patients with any TRAEs |     |                          | 34 | -100 |     |                  |
| Hematologic TRAEs       |     |                          |    |      |     |                  |
| Anemiaa                 |     |                          | 16 |  -47 |     | 4(12)            |
| Thrombocytopeniaa       |     |                          | 11 |  -32 |     | 1(3)             |
| Nonhematologic TRAEs    |     |                          |    |      |     |                  |
| Mucositisa              |     |                          | 27 |  -79 |     | 6(18)            |
| Rasha                   |     |