This study is open to adults with schizophrenia who took part in a previous CONNEX study (study 1346-0011, 1346-0012, or 1346-0013). The purpose of this study is to find out how well people with schizophrenia can tolerate a medicine called Iclepertin in the long term.

Participants take Iclepertin as tablets once a day for 1 year. In addition, all participants take their normal medication for schizophrenia.

Participants are in the study for a little more than 1 year. During this time, they visit the study site about 13 times and get about 9 phone calls from the study team.

The doctors collect information on any health problems of the participants. Doctors also regularly check the participants' symptoms of schizophrenia.

Inclusion criteria:

• Signed and dated written informed consent.
• Clinically stable outpatients who have been diagnosed with schizophrenia (as per Diagnostic and Statistical Manual of Mental Disorders 5th Edition (DSM-5)).
• Patients, who completed participation in the parent trial.
• Women of childbearing potential must use highly effective methods of birth control.
• Have a study partner who interacts with the patient on a regular basis. Further inclusion criteria apply.

Exclusion criteria:

• Participant who developed DSM-5 diagnosis other than Schizophrenia or any condition that would prevent the patient from participating in the extension trial since enrolment into the parent phase III trial.
• Any suicidal behavior and/or suicidal ideation of type 5 based on the Columbia Suicidality Severity Rating Scale (C-SSRS) in parent trial and up to and including Visit 1 of this study.
• Positive urine drug screen ≥ 3 times during the treatment period of parent trial.
• Patients who are currently or wish to participate in another investigational drug trial.
• Any clinically significant finding or condition in the judgment of the investigator that would jeopardize the patient´s safety while participating in the trial or their capability to participate in the trial.

Further exclusion criteria apply.

Once the criteria in section "Time Frame" are fulfilled, researchers can use the following link https://www.clinicalstudies.boehringer-ingelheim.com/msw/datasharing to request access to the clinical study documents regarding this study, and upon a signed "Document Sharing Agreement".

Furthermore, researchers can request access to the clinical study data, for this and other listed studies, after the submission of a research proposal and according to the terms outlined in the website.

After structured results have been posted, all regulatory activities are completed in the US and EU for the product and indication, and after the primary manuscript has been accepted for publication.

For study documents - upon signing of a 'Document Sharing Agreement'. For study data - 1. after the submission and approval of the research proposal (checks will be performed by the sponsor and/or the independent review panel, including checking that the planned analysis does not compete with sponsor's publication plan); 2. and upon signing of a legal agreement.

Boehringer Ingelheim (BI) acknowledges that investigators have the right to publish the study results. Investigators shall provide BI with a copy of any publication or presentation for review prior to any submission. Such review will be done with regard to proprietary information, information related to patentable inventions, medical, scientific, and statistical accuracy within 60 days. BI may request a delay of the publication in order to protect BI's intellectual property rights.