Exhibit 99.1 Acumen Pharmaceuticals Reports First Quarter 2024 Financial Results and Business Highlights • Announced initiation of ALTITUDE-AD, a Phase 2 study to investigate sabirnetug (ACU193) for the treatment of early Alzheimer’s disease, in May 2024 • Initiation of a Phase 1 study to support a subcutaneous dosing option of sabirnetug expected in mid- 2024 • Cash, cash equivalents and marketable securities of $296.6 million as of Mar. 31, 2024, expected to support current clinical and operational activi ...