Company: ERAS
Filing Date: 2025-03-20
Form Type: 10-K
Source: 0000950170-25-042682
Chunk: 38

Company: Erasca, Inc.
Filing Date: 2025-03-20
Form: 10-K
Item: Item 1
Chunk 38
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 these cells to further stimulate EGFR activity and model environments where EGF is expressed. As expected, only the two antibodies that recognized the active state of EGFR, ER-3a/ER-2a, inhibited the proliferation of all three cell lines, as indicated by a reduced confluency percentage.

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ERAS-007: our ERK inhibitor

ERAS-007 is designed to be a potent and selective oral inhibitor of ERK1/2. In preclinical studies, ERAS-007 demonstrated the highest potency and longest target residence time of any ERK inhibitors of which we are aware. We evaluated the safety, tolerability, PK, PD, and preliminary antitumor activity of ERAS-007 in patients with advanced or metastatic solid tumors in our HERKULES series of clinical trials. The final HERKULES trial was deprioritized in May 2024, even though ERAS-007 administered as a monotherapy or in combination was safe and tolerable and achieved confirmed responses in combination with encorafenib and cetuximab in patients with BRAF-mutant CRC. We consider ERAS-007 a potential combination agent with other RAS/MAPK pathway targeting compounds in our pipeline, as well as with standard of care agents.

ERAS-801: our central nervous system (CNS)-penetrant EGFR inhibitor 

ERAS-801 is designed to be a potent, selective, reversible, and orally available small molecule with both: (1) highly enhanced CNS penetration (achieved 8.2:1 brain:plasma ratio in mice, and a mean cerebrospinal fluid (CSF) to unbound plasma concentration ratio (Kp,uu,csf) of 0.9 in human patients), and (2) the ability to target both EGFR mutants such as EGFRvIII, the most common mutant form of EGFR found in GBM, and wtEGFR, which heterodimerizes with EGFRvIII. We evaluated the safety, tolerability, PK, PD, and preliminary antitumor activity of ERAS-801 in patients with recurrent GBM in our THUNDERBBOLT-1 clinical trial. In May 2024, we announced that we had deprioritized the THUNDERBBOLT-1 trial, even though ERAS-801 was tolerable and achieved a confirmed partial response. We are exploring further advancement of the ERAS-801 program, including via partnerships and select investigator-sponsored