Citi | Acumen Pharmaceuticals (ABOS.US): Focus on the Impact of ALTITUDE-AD Later in 2026: Investor Day Takeaways

Acumen hosted an investor day on 16 September ahead of topline data from ALTITUDE-AD, its Phase 2 trial in early Alzheimer's disease, expected later in 2026. Citi maintains a Buy/High Risk rating with a $5.00 target price, implying 73.0% total return from the $2.89 close on 15 September, and has a 90-day upside Catalyst Watch expiring 14 December 2026. The trial enrolled 542 patients with iADRS as primary endpoint; the late-2026 readout spans clinical, safety, amyloid PET, CSF and plasma biomarkers. Citi sees sabirnetug's differentiation in markedly higher selectivity for oligomers over monomers versus marketed antibodies, with its IgG2 backbone potentially delivering lower rates of ARIA, infusion reactions and other inflammatory events. A broad biomarker panel—pTau217, GFAP, neurogranin and amyloid-related markers—could corroborate clinical signals and further validate the oligomer hypothesis. Faster adoption of blood-based biomarkers should expand the diagnosed early-AD population and support broader treatment penetration. The $5.00 target rests on DCF with a 12.5% WACC and 2% terminal growth, with free cash flows projected to 2032; the EBD platform adds long-term optionality with a lead-candidate nomination and IND planned for mid-2027.