A Phase 3 interventional study of ACP-204 in Lewy Body Dementia Psychosis, sponsored by ACADIA Pharmaceuticals Inc.. Recruiting at 36 sites in 6 countries. Open to participants aged 55 Years to 84 Years. Per ClinicalTrials.gov, last updated 2026-11-04.
Sponsored by ACADIA Pharmaceuticals Inc. · Phase 3, Interventional, and Treatment
A 52-Week, Phase 3, Open-Label Extension Study of ACP-204 in Adults With Lewy Body Dementia Psychosis (LBDP)
Study Website: https://illumerastudy.com/
239 studies on the registry are indexed under Lewy Body Disease; 89 are open to participants now.
This study's planned enrollment of 126 is above the median of 89 across 152 interventional studies indexed under Lewy Body Disease.
Browse Lewy Body Disease studies →ACADIA Pharmaceuticals Inc. is the lead sponsor of 41 studies on the registry; 5 are open to participants now.
Of its 26 completed or terminated interventional studies of FDA-regulated products, 24 (92%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Can understand the nature of the study and protocol requirements and provide written . If the subject is deemed not competent to provide informed consent, the following requirements for consent must be met:
If the subject is male, he must agree to the following during the study intervention period and for at least 90 days after the last dose of study drug:
Either
Exclusion Criteria:
Has a laboratory abnormality in the antecedent ACP-204-012 study, excepting at ACP-204-012 EOT, that in the judgment of the Investigator or Medical Monitor, will either:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Initiation of treatment with ACP-204 at a dose of 30 mg once daily. During the trial, the dose may be adjusted, i.e. uptitration to 60 mg in case of suboptimal efficacy or subsequent down titration to 30 mg. Repeated titration steps are allowed.
Drug: ACP-204
Provided as 1 capsule, to be taken orally once daily
Also known as: ACP-204 Tartrate
Proportion of subjects who experience treatment-emergent adverse events (TEAEs)
Time frame: 52 weeks
Plan to share: No
No publications or documents are linked to this record.
Started Nov 2025 (actual). Primary completion is estimated for Feb 2029, 39 months after the start.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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Studies of the drug tested here: Remlifanserin