Company: WHWK
Filing Date: 2025-01-21
Form Type: PREM14A
Source: 0001193125-25-009599
Chunk: 186

Company: Whitehawk Therapeutics, Inc.
Filing Date: 2025-01-21
Form: PREM14A
Chunk 186
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     | SKB518, being developed by Kelun Biotech, is currently in Phase 1 in China. |

We expect multiple external PTK7 ADC programs are projected to present clinical data in 2025 to 2027, which will further validate our target and TOPO1 inhibitor payload approach. Additionally, there are multiple preclinical PTK7 bispecific ADCs in development, including the PTK7 x B7-H3ADC recently acquired by IDEAYA Biosciences. There are a number of other ADC programs in development for NSCLC targeting other tumor-associated antigens. Our Product Candidate: PTK7-CPT113 PTK7-CPT113, as a differentiated next wave PTK7-directed ADC, is poised to be among the first in next wave ADCs with an alternate TOPO1 inhibitor payload to enter the clinic. With its optimized linker and TOPO1 payload switch, we are targeting to build on the initial ORRs seen with Cofe-pand potentially deliver superior outcomes for patients. PTK7-CPT113 has already demonstrated superior tumor reduction compared to Cofe-pin both in vitroand in vivopreclinical models. PTK7-CPT113 shows superior tumor reduction in a lung cancer cell lines compared to similar doses of Cofe-P.The in vivoantitumor studies were conducted with human tumor xenografts with - 123 -

moderate to high PTK7 expression in nude mice (n=8 per xenograft). As shown in the figure below, in human SCLC xenograft models NCI-H446 (PTK7-mod),both PTK7-CPT113 and Cofe-Pshowed clear dose response in antitumor activity but PTK7-CPT113 demonstrated increased antitumor activity compared to Cofe-Pat each corresponding dose with tumor regression achieved by PTK7-CPT113 at higher doses. Similar results were also observed in xenograft models from other tumor types. Clinical Development Plan We plan to complete IND-enablingstudies, linker-payload process development, and CMC and submit an IND for the treatment of solid tumors, including NSCLC and PROC, in the second half of 2025. Subject to FDA acceptance, we plan to initiate a Phase 1 trial by the end of 2025. mMUC16-CPT113

| Overview                                                                                                                                                                                                                                      
 Our product candidate mMUC16-CPT113 is a next wave ADC targeting the membrane-bound portion of MUC16