Company: ERAS
Filing Date: 2025-03-20
Form Type: 10-K
Source: 0000950170-25-042682
Chunk: 21

Company: Erasca, Inc.
Filing Date: 2025-03-20
Form: 10-K
Item: Item 1
Chunk 21
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 PK and PD have been established in both monotherapy and select combinations, with clinical PoC data in combination with trametinib for patients with NRASm melanoma.  

Our development strategy for naporafenib includes our SEACRAFT trials designed to evaluate naporafenib in combination with other targeted therapies. Our SEACRAFT-2 trial is supported by the clinical PoC data in patients with NRASm melanoma that we presented from the SEACRAFT-1 trial at the 2024 Triple Meeting. Clinical PoC in NRASm melanoma is also supported by data presented by Novartis at the ESMO Congress 2022 medical conference and as published in March 2023 by de Braud et al. in the Journal of Clinical Oncology. In connection with our SEACRAFT-2 trial, we have entered into a clinical trial collaboration and supply agreement (CTCSA) with Novartis for its MEK inhibitor, trametinib. Pursuant to the CTCSA, we are sponsoring and funding the clinical trial and Novartis is providing its drug to us free of charge. In addition, we are evaluating additional combinations of naporafenib with our other RAS/MAPK pathway targeting agents and/or external agents in preclinical models.

Preclinical profile of naporafenib

Naporafenib is designed to be a reversible, potent and selective ATP-competitive type 2 pan-RAF kinase inhibitor. It has been shown to be most potent against BRAF and CRAF with biochemical IC50 values of 0.1 and 0.2 nM, respectively, and also showed biochemical activity against ARAF with an IC50 of 6.4 nM. Naporafenib is designed to be selective for RAF family kinases, biochemically inhibiting only three non-RAF kinases at >80% at 1 µM (i.e., PDGFRB, DDR1, and DDR2).

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As a pan-RAF inhibitor, naporafenib is differentiated from BRAF V600E inhibitors since naporafenib inhibits both RAF monomers and dimers. BRAF V600E inhibitors inhibit monomeric BRAF V600E proteins while simultaneously enabling dimerization of these inhibited monomers with uninhibited RAF proteins, thereby resulting in paradoxical activation of downstream RAS/MAPK pathway signaling. Naporafenib’s ability to inhibit both RAF monomers and dimers enables it