Exhibit 99.1 Fulcrum Therapeutics Announces Recent Business Highlights and Financial Results for Third Quarter 2025 ― Announced encouraging results in July 2025 from the 12 mg dose cohort of the Phase 1b PIONEER trial of pociredir in sickle cell disease (SCD) ― ― Enrollment complete in the 20 mg dose cohort (n=12) of the PIONEER trial; on track to provide data from the 20 mg dose cohort by year-end ― ― Ended Q3 2025 with $200.6 million in cash, cash equivalents, and marketable securities; cash runway into 2 ...