Safety and Tolerability of IRL757 in Participants With Parkinson's Disease and Apathy

NCT07461220 | Recruiting Phase 1

• 1 other identifier: IRL757C003
• Study Type: interventional
• Target: 75
• Locations: 4 countries
• Sites: 13

Brief Summary

This clinical trial's goal is to evaluate if the IRL757 is safe and has a good tolerability in participants with Parkinson's disease and experiencing apathy (a lack of interest or motivation). In addition, the trial is aiming to learn if IRL757 has effects on the symptoms of Parkinson's disease. Researchers will compare the effects of IRL757 to a placebo (a look-alike substance that contains no drug). Participants who fit the study criteria will be treated with the study drug (either the active drug IRL757 or placebo) for 12 weeks and will visit the clinic at 5 defined timepoints for check-ups and tests. A follow-up call after the end of treatment will be done 4 weeks after the last study drug intake.

Conditions

PARKINSON DISEASE (Disorder); Apathy; Safety

Outcome Measures

Primary Outcomes (3)

• To evaluate the safety and tolerability of IRL757 after repeated daily dosing for 12 weeks in participants with PD who have moderate to severe symptoms of apathy

  Number of participants with adverse events, classified by severity and relationship to study drug.

  From enrollment [signature of informed consent form] to end of study [4 weeks after last study drug administration]

• To evaluate the safety and tolerability of IRL757 after repeated daily dosing for 12 weeks in participants with PD who have moderate to severe symptoms of apathy

  Number of abnormal clinically significant measures in vital signs (blood pressure, heart rate, respiratory rate) and electrocardiogram (ECG parameters) assessments.

  From enrollment [signature of informed consent form] to end of study [4 weeks after last study drug administration]

• To evaluate the safety and tolerability of IRL757 after repeated daily dosing for 12 weeks in participants with PD who have moderate to severe symptoms of apathy

  Number of participants with abnormal clinically significant findings at physical examination.

  From enrollment [signature of informed consent form] to end of study [4 weeks after last study drug administration]

Secondary Outcomes (2)

• To assess the change from baseline in apathy symptoms using the Neuropsychiatric Inventory Clinician (NPI-C)

  From baseline [last assessment before the first administration of the study drug] until end of treatment at 12 weeks

• To assess the change from baseline in apathy symptoms using the Lille Apathy Rating Scale (LARS)

  From baseline [last assessment before the first administration of the study drug] until end of treatment at 12 weeks

Study Arms (3)

IRL757 Low Dose

EXPERIMENTAL

This is the low dose IRL757. IRL757 will be administered daily for 12 weeks. The study drug is available as capsules for oral administration.

Drug: IRL757

IRL757 High Dose

EXPERIMENTAL

This is the low dose IRL757. IRL757 will be administered daily for 12 weeks. The study drug is available as capsules for oral administration.

Drug: IRL757

Placebo

PLACEBO COMPARATOR

The study drug is administered daily for 12 weeks. The placebo is available in form of capsules to be administered orally, not containing the active substance.

Drug: Placebo

Interventions

IRL757 DRUG

IRL757 will be administered daily for 12 weeks. The study drug is available as capsules for oral administration.

IRL757 High Dose; IRL757 Low Dose

Placebo DRUG

The study drug is administered daily for 12 weeks. The placebo is available in form of capsules to be administered orally.

Placebo

Eligibility Criteria

• Age: 50 Years - 90 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Male and female participants between 50 and 90 years of age, inclusive, with diagnosed Parkinson's disease according to the Movement Disorders Society Clinical Diagnostic Criteria for Parkinson's disease.
• Hoehn and Yahr stage ≤ 4 at screening.
• MoCA score of 20 or greater at screening and baseline.
• Meets the ISCTM definition of apathy (criterion B), defined as exhibiting ≥ 1 symptom in ≥ 2 of the following 3 dimensions, that is persistent or frequently recurrent (ie, ≥ 3 days per week) for ≥ 4 weeks prior to screening:
• Diminished initiative (less spontaneous and/or active than usual self; less likely to initiate usual activities such as hobbies, chores, self-care, conversation, work-related or social activities),
• Diminished interest (less enthusiastic about usual activities, less interested in, or less curious about, events in their environment, less interested in activities and plans made by others, less interested in friends and family, less persistence in maintaining or completing tasks or activities), or
• Diminished emotional expression/responsiveness (less spontaneous emotions, less affectionate compared to their usual self, expresses less emotion in response to positive or negative events, less concerned about the impact of their actions on other people, less empathy).
• The symptoms must represent a significant change from the participant's usual behaviour and cause significant impairment in personal, social, or occupational functioning. Finally, the symptoms must not be due to psychiatric illness, intellectual disability, physical/motor disabilities, or changes in level of consciousness or the effects of substances.
• Participants with moderate to severe apathy based on a score of at least -16 on the LARS at screening and baseline.
• Availability of the primary caregiver, any adult who spends greater than 10 hours a week with the participant and supervises his or her care, to accompany the participant to trial visits and to participate in the trial.
• Treatment with anti-Parkinson drugs, antidepressants (except for those listed as prohibited medications in the protocol), and Choline esterase inhibitors is permitted if doses are stable for 1 month before randomization and remain stable during the trial.

You may not qualify if:

• Any active, current psychiatric comorbidity (such as major depressive disorder, obsessive-compulsive disorder, etc)
• as assessed by the MINI at screening,
• as assessed by the MADRS at the baseline visit with a score \> 18.
• Score of \> 2 in the MDS-UPDRS Part 1, Question 1.2 (hallucinations and psychosis).
• Need for acute psychiatric hospitalization.
• Participants who:
• Answer "Yes" on the C-SSRS Suicidal Ideation Item 4 (Active Suicidal Ideation with Some Intent to Act, Without Specific Plan) within the last 6 months prior to screening or the baseline visit, OR
• Answer "Yes" on the C-SSRS Suicidal Ideation Item 5 (Active Suicidal Ideation with Specific Plan and Intent) within the last 6 months prior to screening or at the baseline visit, OR
• Answer "Yes" on any of the 5 C-SSRS Suicidal Behaviour Items (actual attempt, interrupted attempt, aborted attempt, preparatory acts, or behaviour) within 2 years prior to screening or at the baseline visit, OR
• In the opinion of the investigator, present a serious risk of suicide.
• Subthalamic stimulation of less than 1 year from screening.
• Subthalamic stimulation without stable parameters for 3 months from screening.
• Clinically significant impulse control disorders (ICDs) as assessed by the QUIP RS (score \> 6).
• Renal impairment (estimated glomerular filtration rate \[eGFR\] \< 30 mL/min/1.73m2 calculated based on cystatin C).
• Moderately impaired hepatic function or advanced hepatic dysfunction as assessed by a Child Pugh score B or C.

Sponsors & Collaborators

• Otsuka Pharmaceutical Development & Commercialization, Inc.: collaborator
• Integrative Research Laboratories AB: lead

Study Sites (13)

Medical Center "Galileo" OOD

Pleven, Bulgaria

RECRUITING

First University Multiprofile Hospital for Active Treatment MHAT - Neurology Clinic

Sofia, Bulgaria

RECRUITING

University Multiprofile Hospital for Active Treatment "Alexandrovska" EAD, Clinic of Neurological Diseases

Sofia, Bulgaria

NOT YET RECRUITING

Neurologie Berlin

Berlin, Germany

RECRUITING

Universitaetsklinikum Carl Gustav Carus

Dresden, Germany

NOT YET RECRUITING

Centrum Medyczne NEUROMED

Bydgoszcz, Poland

RECRUITING

Neuro-Care sp. z o.o. sp. Komandytowa

Katowice, Poland

RECRUITING

NeuroKlinika Prof. Andrzej Bogucki

Lodz, Poland

RECRUITING

EuroMedis Sp. z o.o.

Szczecin, Poland

RECRUITING

Centrum Medyczne NeuroProtect

Warsaw, Poland

NOT YET RECRUITING

Hospital de la Santa Creu i Sant Pau, Unidad de trastornos del movimiento

Barcelona, Spain

RECRUITING

Hospital General Universitario de Elche

Elche, Spain

NOT YET RECRUITING

Hospital Universitario Ramon y Cajal

Madrid, Spain

RECRUITING

MeSH Terms

Conditions

Parkinson Disease; Lethargy

Condition Hierarchy (Ancestors)

Parkinsonian Disorders; Basal Ganglia Diseases; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Movement Disorders; Synucleinopathies; Neurodegenerative Diseases; Neurobehavioral Manifestations; Neurologic Manifestations; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Central Study Contacts

Joakim Tedroff

CONTACT

+46 31 757 38 00; info@irlab.se

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: February 17, 2026
• First Posted: March 10, 2026
• Study Start: February 18, 2026
• Primary Completion (Estimated): May 1, 2027
• Study Completion (Estimated): May 1, 2027
• Last Updated: March 10, 2026

Record last verified: 2026-03

Locations

DE (2); PL (5); ES (3); BU (3)