An open label, single arm, extension trial to examine long-term safety of Iclepertin once daily in patients with schizophrenia who have completed previous Iclepertin Phase III trials (CONNEX-X).

1. Signed and dated written informed consent in accordance with ICH Harmonized
Tripartite Guideline for Good Clinical Practice (ICH-GCP) and local legislation
prior to admission to the trial (Visit 1).
2. Clinically stable outpatients who have been diagnosed with schizophrenia (as
per Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5)).
3. Patients, who completed 26 weeks of treatment in the parent trial, must
enter the extension trial within:
• Within 2 weeks after the end of treatment visit in 1346-0011, 1346-0013 (i.e.
Follow Up 1 timepoint including the applicable time windows).
• At the end of safety follow up in 1346-0012 (within 7 days of visit Follow Up
6).
4. Women of childbearning potential (WOCBP) must be ready and able to use
highly effective methods of birth control per Non-Clinical Safety Studies for
the Conduct of Human Clinical Trials and Marketing Authorization for
Pharmaceuticals (ICH M3 (R2)) that result in a low failure rate of less than 1%
per year when used consistently and correctly. Such methods should be used
throughout the trial, and for a period of at least 35 days after last trial
drug intake, and the patient must agree to periodic pregnancy testing during
participation in the trial.
5. Have a study partner, defined as any person capable of understanding trial
related procedures, with a minimum of 8th grade level of education, who knows
the patient well, has been capable of interacting with the patient on regular
basis (at least once a week, either private or professional). Study partner
does not need to attend visits with the patient but must be reachable by phone.
Study partner should preferably be the same person throughout the study, if
possible
• Professional study partner (e.g. study nurse, social worker etc.) are allowed
if not involved in administering any of the protocol assessments.

1. Participant who developed DSM5 diagnosis other than Schizophrenia or any
condition that would prevent the patient from participating in the extension
trial (e.g. stroke, head trauma, developed dementia, severe uncontrolled
movement disorders or other significant condition since enrolment into the
parent phase III trial).
2. Any suicidal behavior and/ or suicidal ideation of type 5 based on the
C-SSRS in parent trial and up to and including Visit 1 of this study.
o Patients with Suicidal Ideation type 4 in the C-SSRS (active suicidal thought
with intent but without specific plan), in the past 3 months prior to and
including Visit 1, can be entered in the study, if assessed and documented by a
licensed mental health professional that there is no immediate risk of suicide.
3. Patients diagnosed with moderate or severe substance use disorder (other
than caffeine and nicotine), as defined in DSM-5 while the patient was in
parent trial and prior to Visit 1 of this study.
4. Positive urine drug screen >= 3 times during the parent trial based on
central lab test.
5. Patients who are currently or wish to participate in another investigational
drug trial.
6. Any clinically significant finding in the judgment of the investigator
such as :
o Clinically significant finding on he Physical examination and/or ECG from
the last assessment done in the parent trial.
o Vital signs (including blood pressure (BP) and pulse rate (PR)) that would
jeopardize the patient*s safety while participating in the trial or their
capability to participate in the trial.
o Symptomatic/unstable/uncontrolled or clinically relevant concomitant disease
or any other clinical condition that would jeopardize the patient*s safety
while participating in the trial or capability to participate in the trial.
o Significant or unstable physical condition that may require change in
medication or hospitalization that would impact cognitive function.
7. Any significant central lab findings based on the last available lab result
received during the parent trial such as:
o Severe renal impairment defined as an eGFR < 30mL/min/1.73m²,
o Indication of liver disease, defined by serum levels of either ALT (SGPT),
AST (SGOT), or alkaline phosphatase above 3 times upper limit or normal or
o Hb drop below 100g/L (10g/dL) OR Hb decrease of 25% or more from baseline
and is below lower limit of normal in parent trial (alert 3 from last measure
Hb in parental trial)
o Patients who meet any of the withdrawal criteria before planned end of
treatment (26 weeks) in parent trial.
8. Patients who have been diagnosed with hemoglobinopathies during the parent
trial.
9. Patients with known ongoing severe or serious infection with SARS-CoV-2.
10. Known history of HIV and/or known on-going Hepatitis B or C infections. As
well as any documented active or suspected malignancy or history of malignancy
within 5 years prior to screening, except appropriately treated basal cell
carcinoma of the skin, squamous cell carcinoma of the skin or in situ carcinoma
of uterine cervix.
11. Women who are pregnant, nursing, or who plan to become pregnant while in
the trial.
12. Patients with an allergy to BI 425809 and/or any of the excipients
(including serious lactose intolerance).
13. Patients who are currently treated or expected to be treated with any of
the following: strong or moderate CYP3A4 inhibitors, strong or moderate CYP3A4
inducers, CYP3A4 sensitive substrates,. including grapefruit juice ad St.
John*s wort (Hypericum perforatum) and substrates with a narrow therapeutic
range (e.g., fentanyl, cyclosporine).