Company: DAWN
Filing Date: 2025-02-25
Form Type: 10-K
Source: 0000950170-25-026654
Chunk: 340

Company: Day One Biopharmaceuticals, Inc.
Filing Date: 2025-02-25
Form: 10-K
Item: Item 7
Chunk 340
---
, and commercialize pharmaceutical products and to engage in research aimed at discovery, optimization and development of an inhibitor targeting Vaccinia Related Kinase 1, or VRK1. VRK1 is a novel target involved in the regulation of cell division and DNA damage repair. Over-expression of VRK1 is linked to poor prognosis in a variety of adult and pediatric cancers, and VRK1 has been identified as a 

112

synthetic lethal target in tumors where expression of its paralog, VRK2, is lost. Silencing of VRK2 expression via promoter methylation has been noted in most high-grade gliomas and high-risk neuroblastomas, providing a concrete approach for selecting patients with tumors sensitive to VRK1 inhibition. Preclinical research activities to advance the VRK1 inhibitor program are ongoing.

In June 2024, we entered into a license agreement, or the MabCare License Agreement, with MabCare Therapeutics, or MabCare, a pharmaceutical corporation located in Shanghai, China. Under the MabCare License Agreement, MabCare granted to us an exclusive worldwide license, excluding Greater China, with the right to grant sublicenses through multiple tiers, under specified patent rights and know-how for the Company to develop, manufacture and commercialize DAY301 (formerly MTX-13 or CB-002). DAY301 is a novel Antibody Drug Conjugate, or ADC, targeting protein-tyrosine kinase 7, or PTK7.  In pre-clinical studies, DAY301 showed antitumor activity in a wide range of solid tumors. DAY301 targets PTK7, a highly-conserved, catalytically inactive transmembrane protein that is overexpressed in multiple adult cancers, including esophageal, ovarian, lung, and endometrial cancer, as well as pediatric cancers such as neuroblastoma, rhabdomyosarcoma and osteosarcoma. In April 2024, the FDA cleared the investigational new drug application for DAY301. In January 2025, we cleared the first cohort (a single-patient accelerated titration cohort) in the Phase 1a portion of the DAY301 Phase 1a/b clinical trial.

We believe our business development capabilities combined with our extensive experience in oncology drug development and deep ties within the research and patient advocacy communities, particularly within the pediatric setting, positions us to be a leader in identifying, acquiring and developing therapies for patients of all ages. We hold exclusive rights to develop tovorafen