Erasca, Inc.

Our corporate headquarters is located in San Diego, California, where we lease approximately 78,000 square feet of office and laboratory space pursuant to a lease that expires in April 2032 and may be terminated early under certain circumstances. In January 2024, we entered into an agreement to sublease the second floor of our corporate headquarters (the January 2024 Sublease). Pursuant to the January 2024 Sublease, the subleased space was approximately 11,000 square feet of office space with a sublease term of three years which included an option for the subtenant to renew for an additional year and an early termination clause. In June 2025, we and the subtenant entered into a termination agreement that terminated the January 2024 Sublease in July 2025. In July 2024, we entered into an agreement to sublease the first floor of our corporate headquarters (the July 2024 Sublease). Pursuant to the July 2024 Sublease, the subleased space is approximately 18,000 square feet of office space with a sublease term of 61 months beginning in October 2024. The July 2024 Sublease includes an option for the subtenant to renew for an additional year and an early termination clause. In September 2024, we entered into an agreement to sublease a portion of the third floor of our corporate headquarters (the September 2024 Sublease). Pursuant to the September 2024 Sublease, the subleased space was approximately 5,000 square feet of laboratory space with a sublease term of one year, which included an option for the subtenant to renew for an additional year. In July 2025, the September 2024 Sublease was amended to: (i) add approximately 5,000 square feet of laboratory space on the third floor and approximately 11,000 square feet of office space on the second floor to the subleased space; and (ii) to extend the term of the September 2024 Sublease through December 31, 2027. The amendment to the September 2024 Sublease includes an option for the subtenant to renew for an additional year.

We also lease approximately 30,000 square feet of office and laboratory space in South San Francisco, California, pursuant to a lease that expires in October 2032, with an option to extend the term by five years, subject to certain conditions.

We believe our existing facilities are adequate to meet our current business requirements for the near term, and that additional space will be available on commercially reasonable terms, if required.