Study to Assess the Safety and Effectiveness of NMRA-335140-501

Key Inclusion Criteria: Rollover participants are eligible for the study if the following inclusion criteria are met: * Completed a previous NMRA-335140 Phase 3 MDD study (example: NMRA-335140-301, NMRA-335140-302, or NMRA-335140-303) according to the completion definition in the parent study protocol. * Signed an informed consent form (ICF) for this study. * Willing to comply with the contraception requirements described in the inclusion criteria of the parent study protocol. * Willing to comply with the concomitant medication/therapy restrictions described in the exclusion criteria of the parent study protocol. Key Exclusion Criteria: Rollover participants are excluded from the study if any of the following exclusion criteria are met: * Diagnosed with another Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (DSM-5-TR) disorder that would have been exclusionary in the parent study (eg, personality disorder, bipolar 1 or 2, schizophrenia, any other psychotic disorder, or moderate or severe substance or alcohol use disorder \[excluding nicotine\]). * Considered to be at significant risk of suicide in the judgment of the Investigator. This includes participants who are actively suicidal (eg, any suicide attempts during the parent study) or are at serious suicidal risk as indicated by any current suicidal intent, including a plan, as assessed by the C-SSRS ("Since Last Visit" version, score of "YES" on suicidal ideation Item 4 or 5) and/or based on clinical evaluation by the Investigator; or are homicidal, in the opinion of the Investigator. * Non-adherent with study medication (took ≤70% of study drug over any 2-week visit interval) or procedures during the parent study. * Experienced treatment emergent adverse events (TEAEs) considered related to the study medication from the parent study and judged by the Investigator to be clinically significant to render the participant ineligible for enrollment. * Have an abnormality on ocular examination that would prohibit continued study participation as determined by the Investigator. * Use of disallowed concomitant medication or therapy that would have been exclusionary in the parent study, may compromise the safety of the participant, and/or confound the interpretation of protocol assessments. * Considered by the Investigator to be inappropriate for any other reason.