Company: WHWK
Filing Date: 2025-04-25
Form Type: 424B5
Source: 0001193125-25-097064
Chunk: 22

Company: Whitehawk Therapeutics, Inc.
Filing Date: 2025-04-25
Form: 424B5
Chunk 22
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     | 9 patients had stable disease (SD), 3 of which were greater than or equal to six months in duration, resulting in 
 a clinical benefit rate of 42% (5 PR + 3 SD ≥ 6 months)                                                           |

| • |     | Patients were heavily pre-treated with median of 3 prior lines of therapy |

| • |     | Median time to response was 1.4 months and all responses were ongoing at time of data cutoff |

| • |     | Responses were seen across four different epithelial carcinomas |

| • |     | 60% of responders experienced > 50% tumor reduction |

With respect to the efficacy of nab-sirolimusin patients with tumors harboring pathogenic inactivating alteration in TSC2, of the 18 patients enrolled, all 18 patients received ≥ 1 post baseline scan and were evaluable for efficacy. Observations included:

| • |     | An 11% ORR including 2 PRs with 1 confirmed and 1 uPR |

| • |     | 12 patients had SD, 3 of which were greater than or equal to six months resulting in a clinical benefit rate of 
 28% (2 PR + 3 SD ≥ 6 mos)                                                                                       |

| • |     | Patients were heavily pre-treated with median of 3.5 prior lines of 
 therapy; 50% had ≥ 5 prior lines of therapy                         |

| • |     | Responses were seen in one epithelial carcinoma and one sarcoma |

No new safety signals were observed, and no grade four treatment-related events or deaths occurred. One patient discontinued the study due to grade two pneumonitis that completely resolved after discontinuation of therapy. Across both arms, the safety profile was consistent with the nab-sirolimuslabel and the mTOR inhibitor drug class. As of December 14, 2023, 80 patients were enrolled in the PRECISION1 trial, supporting the two-thirdsinterim analysis expected in the third quarter of 2024. The ORR analysis in this cohort will be based on independent radiological review with a minimum of six months of follow-upfor all patients. The trial is expected to be completed by the end of 2024 with results anticipated in early 2025. On August 9, 2023, we announced the expansion of our FYARRO pipeline through the further investigation of mTOR pathway inhibition in endometrial cancer and neuroendocrine tumors (NETs