Study Evaluating Safety and Efficacy of Ropanicant in MDD Patients

Approximately 36 participants will be randomly assigned to receive Ropanicant either Ropanicant 45 mg once a day (QD), Ropanicant 30 mg twice a day (BID), or Ropanicant 45 mg BID for 2 weeks, in a ratio of 1:1:1 (12 participants in each treatment group). Following a screening period of up to 4 weeks, the participants will be treated for 2 weeks.

Inclusion criteria

• Participants must meet the DSM-5 criteria for MDD without psychotic features and diagnosis confirmed by the Mini-International Neuropsychiatric Interview (MINI).
• Participants with a current major depressive episode of at least 4 weeks of duration prior to the screening visit.
• Participants must have an MADRS score of ≥25 at the screening and the baseline visits.
• Participants must have a score of ≥4 on Clinical Global Impression - Severity (CGI-S) Scale at the screening and the baseline visits.

Exclusion criteria

• Participants who meet criteria for treatment-resistant depression during the current major depressive episode, which will be defined as being non-responders (less than 50% of symptom improvement) to 2 or more depression treatment periods of adequate dose and duration as defined by the Massachusetts General Hospital (MGH) Antidepressant Treatment Response Questionnaire (ATRQ).
• Participants taking antidepressant treatment (SSRIs and SNRIs) or any medication that is contraindicated with the use of monoamine oxidase inhibitors (eg, opioids, stimulants) within 2 weeks (or 5 half-lives, whichever is longer) prior to baseline and until the end of study visit.
• Participants who do not agree to avoid tyramine rich diet from the start of dosing and until 2 weeks following last study drug administration.
• Participants who are habitual smokers or using nicotine products.