Single and Multiple Ascending Doses of NTX-253 in Healthy Participants and Participants With Stable Schizophrenia

A First in Human, Phase 1/1b Study of Single and Multiple Ascending Dosing Administration of NTX110253 in Healthy Participants and Participants With Stable Schizophrenia

This study will assess the safety, tolerability, and pharmacokinetics of NTX-253 following oral administration in both healthy adult participants as well as adult participants with stable schizophrenia.

This study will assess the safety, tolerability, and pharmacokinetics of NTX-253 following oral administration in both healthy adult participants as well as adult participants with stable schizophrenia. NTX-253 is an investigational drug being developed for the treatment of schizophrenia. The study will consist of a single ascending dose (SAD - Part 1a) phase which will include a food effect cohort, and a cerebrospinal fluid (CSF - Part 1b) cohort in healthy volunteers. Participants will receive a single dose of either oral NTX-253 or placebo. The multiple ascending dose (MAD - Part 2) phase will follow. In Part 2, participants will be dosed for 10 consecutive days with either NTX-253 or placebo. Each phase will include sequential escalating doses in healthy volunteers. Two cohorts in the MAD phase will include stable schizophrenic adult participants who have had antipsychotic medication withdrawn for up to 8 days prior to dosing with NTX-253.

Primary Inclusion Criteria:

• Male or non-pregnant, non-lactating female participants, ages 18-55 who are not of childbearing potential, with a truly abstinent lifestyle, or agrees to use medically acceptable forms of birth control
• Part 1 a/b, Part 2 Cohort 7 only: Body mass index (BMI) within the range ≥18.0 to ≤30.0 kg/m2
• Participants in the food effect cohort must be willing to eat a single high fat breakfast
• (Part 2 only): Stable schizophrenia participants (schizophrenia cohorts only)
• Body mass index (BMI) within the range ≥17.5 to ≤36.0 kg/m2
• Positive and Negative Syndrome Scale (PANSS) total score <80 at screening

Primary Exclusion Criteria:

• (Part 1a/b, Part 2 Healthy): History of or current clinically significant medical or mental illness
• Cancer diagnosis/treatment in the past 7 years
• Acute or chronic gastrointestinal conditions that would interfere with drug tolerance or absorption
• Any clinically significant, abnormal 12 lead ECG
• Part 2: Any primary DSM-5TR disorder other than schizophrenia
• Participants with schizophrenia who are considered resistant/refractory to antipsychotic treatment by history; history of clozapine use.