Evaluation of Long-Term Safety and Tolerability of ACP-204 Tartrate in Adults with Alzheimer's Disease Psychosis: A 52-Week Open-Label Extension Study

The primary objective of this 52-week, open-label extension study is to evaluate the **safety** and **tolerability** of long-term treatment with ACP-204 in adults diagnosed with **Alzheimer's Disease Psychosis** (ADP). This is clinically relevant as it aims to assess the potential for sustained use of ACP-204, which could provide a therapeutic option for managing psychosis symptoms in this patient population. The study does not list any secondary objectives.

The clinical trial involves a total of **556 participants** diagnosed with **Alzheimer's Disease Psychosis**. The study population comprises both male and female subjects, aged between **55 to 85 years**. Participants were selected based on their successful completion of the ACP-204-006 study and must have a designated study partner or caregiver to assist with study visits. The trial includes individuals who are able to provide informed consent, either personally or through a legal representative. The study population is characterized by a vulnerable group, necessitating careful consideration of their health status and support systems. Participants are required to adhere to specific lifestyle considerations, including the use of appropriate contraceptive methods for males with partners of childbearing potential. The trial aims to evaluate the safety and tolerability of long-term ACP-204 treatment in this demographic.

The clinical trial is designed as a **52-week, open-label extension study** to evaluate the long-term safety and tolerability of **ACP-204** in adults with **Alzheimer's Disease Psychosis**. The study follows a non-randomized, open-label design, allowing all participants to receive the investigational product. The trial will involve oral administration of ACP-204 in capsule form, with a maximum daily dose of 60 mg and a total dose not exceeding 21,840 mg over the study period. Participants are required to have successfully completed a prior study, ACP-204-006, and must be between the ages of 55 and 85. Both male and female participants are eligible, with specific contraceptive requirements for males if their partners are of childbearing potential. A designated study partner or caregiver must accompany participants to all study visits.

The trial will commence with an inclusion (screening) visit to confirm eligibility based on the principal inclusion criteria. Following this, participants will undergo regular follow-up visits throughout the 52-week period to monitor safety and tolerability, with a focus on treatment-emergent adverse events. The primary endpoint is the number of subjects experiencing adverse events, discontinuations due to adverse events, and serious adverse events. Secondary endpoints include the Clinical Global Impression-Improvement score in the context of Alzheimer's Disease Psychosis. The study will conclude with an end-of-study visit to assess the overall outcomes and gather final data.

Participant involvement is expected to last for the entire 52-week duration unless early termination is warranted. Conditions that may lead to early termination include the occurrence of serious adverse events or the participant's inability to comply with study requirements. The trial is set to begin recruitment on September 1, 2024, with an estimated end date of September 30, 2029. The study is not classified as a low-intervention trial and is categorized as a Phase III trial, focusing on the long-term effects of ACP-204 in the specified patient population.

The clinical trial involves the administration of **ACP-204 tartrate**, an investigational medication developed by Acadia Pharmaceuticals. The pharmaceutical form of ACP-204 is a **capsule**, designed for **oral use**. The active substance, ACP-204 tartrate, is of chemical origin. Participants in the trial will receive a maximum daily dose of 60 mg, with the total dose not exceeding 21,840 mg over the course of the study. The treatment period is set for a maximum of 52 weeks. The medication is not formulated for pediatric use and is not classified as an orphan drug. The study aims to evaluate the safety and tolerability of long-term ACP-204 treatment in adults with Alzheimer's Disease Psychosis.

In addition to the experimental treatment, the study may include the use of standard-of-care therapies as deemed necessary by the clinical investigators. No placebo or active comparator treatments are specified in the trial protocol. Compliance with the dosing schedule will be monitored throughout the study to ensure adherence to the prescribed regimen. Participants' adherence to the medication regimen will be assessed through regular follow-ups and pill counts, ensuring accurate data collection and analysis.

Efficacy in the clinical trial titled "A 52-Week, Open-Label Extension Study of ACP-204 in Adults with Alzheimer's Disease Psychosis" will be assessed using specific endpoints. The primary endpoint focuses on the safety profile, specifically the number of subjects experiencing treatment-emergent adverse events (AEs), discontinuations due to AEs, and serious adverse events (SAEs) over the 52-week treatment period. This will be evaluated in the safety population, which includes all subjects who receive at least one dose of the study drug.

The secondary endpoint involves the assessment of the Clinical Global Impression-Improvement in the context of Alzheimer's Disease Psychosis (CGI-I-ADP) score, also measured over the 52-week period. This score is a recognized tool for evaluating symptom improvement in clinical settings. The collection and analysis of these efficacy parameters will be conducted throughout the study duration, ensuring comprehensive monitoring of the treatment's impact on participants.