Company: ERAS
Filing Date: 2025-03-20
Form Type: 10-K
Source: 0000950170-25-042682
Chunk: 4

Company: Erasca, Inc.
Filing Date: 2025-03-20
Form: 10-K
Item: Item 1
Chunk 4
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 trametinib in the melanoma cohort of SEACRAFT-1 include, as of the efficacy cutoff date*:

•40% (4/10) response rate observed in the efficacy-evaluable patients with NRAS Q61X melanoma, including three confirmed partial responses and one unconfirmed partial response; the melanoma cohort in SEACRAFT-1 is generally representative of the patient population currently being enrolled in the pivotal SEACRAFT-2 trial 

•70% (7/10) of patients remained on treatment as of the data cutoff, including all four responders 

In addition, we reported that naporafenib plus trametinib was generally well tolerated as of the safety cutoff date*, with mostly low-grade adverse events in the majority of patients. We believe that the use of mandatory primary rash prophylaxis helped reduce the frequency and severity of skin toxicities, reduced the drug discontinuation rate due to adverse events, and improved the observed tolerability results as measured by the increased relative dose intensity, as compared to the prior clinical trials of naporafenib plus trametinib conducted by Novartis, which did not include the use of mandatory primary rash prophylaxis.

* Efficacy data cutoff date was September 5, 2024. Safety data cutoff date was September 3, 2024.

We believe that while the preliminary SEACRAFT-1 data do not support further exploration of a tissue-agnostic indication, they do reinforce the potential of the ongoing Phase 3 SEACRAFT-2 trial in patients with NRASm melanoma. We expect to read out randomized dose optimization data of naporafenib plus trametinib from Stage 1 of the SEACRAFT-2 Phase 3 trial in the second half of 2025. Stage 2 of the SEACRAFT-2 Phase 3 trial is currently designed to compare naporafenib plus trametinib against physician's choice of chemotherapy or trametinib using dual primary endpoints of progression free survival and overall survival for regulatory approval.

Our next two programs are part of our RAS-targeting franchise, which we in-licensed in May 2024. We believe these two programs fit within our second approach of targeting RAS directly, both in its active GTP and inactive GDP states. The RAS targeting landscape can be divided into pan-RAS, pan-KRAS, and mutant-selective approaches. We believe pan-RAS and pan-KRAS targeting molecules can address a broad population