Developer · ACAD · United States

ACADIA Pharmaceuticals Inc.

Biopharmaceutical company headquartered in San Diego, California (Nasdaq: ACAD), focused on CNS disorders and rare diseases. Markets pimavanserin (NUPLAZID) for hallucinations and delusions associated with Parkinson's disease psychosis and trofinetide (DAYBUE) for Rett syndrome. Its lead clinical CNS asset is remlifanserin (ACP-204), a second-generation selective 5-HT2A inverse agonist in Alzheimer's disease psychosis and Lewy body dementia psychosis.

acadia.com ↗

1compound
2programs
2indications
Phase 3lead asset

Phase distribution

  • Phase 31
  • Phase 21

Modality

  • Small molecule 1

Mechanism focus

Pipeline (1)

Catalysts · 3 upcoming

  • September to October 2026Anticipated

    RemlifanserinforAlzheimer's disease psychosisTopline data

    Topline results from the Phase 2 RADIANT substudy of remlifanserin (ACP-204) 30 mg and 60 mg vs placebo in Alzheimer's disease psychosis (primary endpoint: change from baseline in SAPS-H+D at Week 6), expected September–October 2026.

    NCT06159673source ↗

  • January 2028Anticipated

    RemlifanserinforAlzheimer's disease psychosisRegistry results

    ClinicalTrials.gov estimated primary completion of the full RADIANT master protocol (NCT06159673), which covers both Phase 3 confirmatory substudies: January 2028 (estimated study completion February 2028).

    NCT06159673source ↗

  • February 2028Anticipated

    RemlifanserinforLewy body dementia psychosisRegistry results

    ClinicalTrials.gov estimated primary completion of the Phase 2 Lewy body dementia psychosis efficacy study (NCT07029581, ACP-204-012): February 2028 (estimated study completion March 2028).

    NCT07029581source ↗

Recent activity

  • Jul 20, 2026Phase changeRemlifanserin·Alzheimer's disease psychosisPhase 3First dated public confirmation that the program is in Phase 3: ACADIA stated that enrollment in the Phase 2 portion of RADIANT is complete, that topline is expected September–October 2026, and that screening and enrollment are underway in the Phase 3 studies. The same release announced FDA Fast Track designation for remlifanserin in ADP. ACADIA has not disclosed the exact date the Phase 3 substudies opened, so this date is an upper bound — the true transition is on or before 2026-07-20.source ↗
  • Nov 14, 2025Phase changeRemlifanserin·Lewy body dementia psychosisPhase 252-week open-label extension NCT07095465 (ACP-204-013) started, enrolling by invitation (126 subjects; primary outcome proportion of subjects with TEAEs; estimated primary completion February 2029). Registered on ClinicalTrials.gov as Phase 3, but as a safety extension it is not treated as a Phase 3 advance for this program.source ↗
  • Nov 5, 2025Phase changeRemlifanserin·Lewy body dementia psychosisPhase 2ACADIA publicly confirmed the program in its Q3 2025 financial results and operating overview, citing initiation of a Phase 2 study of ACP-204 for Lewy Body Dementia Psychosis as a pipeline advance for the quarter.source ↗
  • Aug 6, 2025Phase changeRemlifanserin·Lewy body dementia psychosisPhase 2Phase 2 LBDP efficacy/safety study NCT07029581 (ACP-204-012) start date per ClinicalTrials.gov: 180 participants, ACP-204 30 mg / 60 mg / placebo, 6-week double-blind parallel-group design, primary endpoint change from baseline in SAPS-LBDP total score at Week 6. Estimated primary completion February 2028, study completion March 2028. Delivers on the Q3 2025 initiation target set at the 2025-06-25 R&D Day.source ↗
  • Apr 23, 2024Phase changeRemlifanserin·Alzheimer's disease psychosisPhase 252-week open-label extension NCT06194799 (ACP-204-008) started, enrolling by invitation from the RADIANT substudies (752 subjects; primary outcome treatment-emergent adverse events). Registered on ClinicalTrials.gov as Phase 3, but it is a long-term safety extension rather than a confirmatory efficacy study, so it is not treated here as the Phase 3 advance.source ↗
  • Nov 14, 2023Phase changeRemlifanserin·Alzheimer's disease psychosisPhase 2RADIANT master protocol NCT06159673 (ACP-204-006) started per ClinicalTrials.gov: a seamless Phase 2/Phase 3 program in Alzheimer's disease psychosis. ACADIA announced initiation of the Phase 2 substudy on 2023-11-27 (~318 patients, ACP-204 30 mg or 60 mg vs placebo, 6 weeks, primary endpoint change from baseline in SAPS-H+D at Week 6; two ~378-patient Phase 3 substudies planned with near-identical design).source ↗

Trials recruiting · 5 recruiting of 33 sponsored

  • Phase 3Remlifanserinn=12615 sites · United States, Bulgaria, Czechia

    52-Week, Phase 3, Open-Label Extension Study of ACP-204 in Adults With Lewy Body Dementia Psychosis (LBDP)

    Lewy Body Dementia PsychosisNCT07095465 ↗

  • Phase 3Remlifanserinn=75271 sites · United States, Serbia, Brazil

    A 52-Week, Open-Label Extension Study of ACP-204 in Adults With Alzheimer's Disease Psychosis

    Alzheimer's Disease PsychosisNCT06194799 ↗

  • Phase 2/3Remlifanserinn=1074145 sites · United States, Brazil, Bulgaria

    A Master Protocol for Three Independent, Seamlessly Enrolling, Double-blind, Placebo-controlled Efficacy and Safety Studies of ACP-204 in Adults With Alzheimer's Disease Psychosis

    Alzheimer's Disease PsychosisNCT06159673 ↗

  • Phase 2ACP-211, Placebon=15321 sites · United States

    ACP-211 Monotherapy for Major Depressive Disorder With Inadequate Antidepressant Response

    Major Depressive Disorder (MDD)Depressive Disorder, Treatment-ResistantNCT07284667 ↗

  • Phase 2Remlifanserinn=18056 sites · United States, France, Bulgaria

    A Double-Blind, Placebo-Controlled, Phase 2, Efficacy and Safety Study of ACP-204 in Adults With Lewy Body Dementia Psychosis (LBDP)

    Lewy Body Dementia PsychosisNCT07029581 ↗

Competitive landscape

Other companies developing against ACADIA Pharmaceuticals Inc.'s targets or indications.