This study is open to adults with schizophrenia. Schizophrenia can affect the way a person thinks, their memory and their mental functioning. Examples include struggling to remember things, or to read a book or pay attention to a movie. Some people have difficulty calculating the right change or planning a trip so that they arrive on time. The purpose of this study is to find out whether a medicine called iclepertin improves learning and memory in people with schizophrenia.

Participants are put into two groups randomly, which means by chance. One group takes iclepertin tablets and the other group takes placebo tablets. Placebo tablets look like iclepertin tablets but do not contain any medicine. Participants take a tablet once a day for 26 weeks. In addition, all participants take their normal medication for schizophrenia.

During this time, doctors regularly test learning and memory of the participants by use of questionnaires, interviews, and computer tests. The results of the mental ability tests are compared between the groups.

Participants are in the study for about 8 months and visit the study site about 14 times. During this time, doctors regularly check participants' health and take note of any unwanted effects.