Company: WHWK
Filing Date: 2025-01-31
Form Type: DEFM14A
Source: 0001193125-25-018470
Chunk: 178

Company: Whitehawk Therapeutics, Inc.
Filing Date: 2025-01-31
Form: DEFM14A
Chunk 178
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 | JAMA Oncol. 2017;3(10):1335-1342. |

PTK7-CPT113 Overview

| Our lead product candidate PTK7-CPT113 is a next wave ADC with a DAR of 6 targeting PTK7 that we plan to                                                                                                                                     |
| develop for the treatment of non-small cell lung cancer (“NSCLC”) and platinum resistant                                                                                                                                                     
 ovarian cancer (“PROC”), with potential to expand into other indications. We believe PTK7-CPT113 has the potential to be among the first in next wave ADCs with a TOPO1 inhibitor payload to enter the clinic. With its optimized linker and 
 TOPO1 inhibitor payload, we hope to improve upon the initial ORRs seen with cofetuzumab pelidotin (“Cofe-p”), a first generation MMAE-based ADC with a DAR 4 targeting PTK7.                                                                 
 PTK7-CPT113 has shown superior cytotoxic activity compared to a first generation                                                                                                                                                             
 MMAE-based PTK7 ADC in both in vitro and in vivo preclinical models. We are currently completing IND-enabling studies and expect to submit an IND for the use of PTK7-CPT113 in treating                                                     
 solid tumors, including NSCLC and PROC, in the second half of 2025.   Target                                                                                                                                                                 
 Overview: Protein tyrosine kinase 7 (PTK7)   Protein tyrosine kinase 7                                                                                                                                                                       
 (“PTK7”) is an oncofetal pseudokinase also known as colon carcinoma kinase 4 (“CCK-4”). PTK7 is a transmembrane protein with an extracellular region comprised of 7 Ig domains and an                                                        
 intracellular domain that is non-catalytic.                                                                                                                                                                                                  |

PTK7 drives embryonic early development by regulating cell polarity, movement and development of hematopoietic and somatic progenitor cells often interacting with ligands, co-receptorsand intracellular transducers in the Wnt signaling pathway. PTK7 is subsequently down-regulated in adult tissues and is known as - 121 -

a catalytically inactive receptor tyrosine kinase (“RTK”). PTK7 is commonly upregulated across a broad spectrum of cancers, being found in tumors associated with endometrial, prostate, cervical, head and neck, breast, colorectal, esophageal, lung, ovarian and gastric intestinal cancers, as shown in the figure below. In fact, PTK7 is almost exclusively re-ex