How to Identify Treatment-Resistant Depression for Onfasprodil Consideration
How do clinicians identify adults with major depressive disorder who match the treatment-resistant depression population studied for intravenous onfasprodil?
Patients with persistent major depressive episodes after multiple adequate antidepressant trials may need rapid-acting options beyond standard oral treatment. This guide applies to adults being considered for an onfasprodil-like intravenous approach and focuses on the eligibility features used in this proof-of-concept trial.
-
Confirm current major depressive disorder episode
Identify adults aged 18 to 65 years with major depressive disorder who are currently in a major depressive episode per DSM-5 criteria. In this study, patients had to be in an active depressive episode at enrollment.
-
Verify antidepressant treatment resistance
Document prior failure of at least 2 standard antidepressants at adequate dose. The article further specifies that the 2 failed treatments had to be different antidepressants, and at least 1 of those failed treatments had to have been taken during the current depressive episode.
-
Establish episode duration and symptom severity
Confirm that the current major depressive episode has lasted at least 8 weeks. Rate depression severity with the Montgomery-Asberg Depression Rating Scale and verify a baseline MADRS total score of 24 or higher, which was required for study entry.
-
Use study-supported dosing options only as investigational reference points
If comparing a patient to the studied population, note that the trial tested intravenous onfasprodil 0.16 mg/kg or 0.32 mg/kg infused over 40 minutes either weekly from Day 1 to Day 36 or biweekly on Day 1, Day 15, and Day 29 with placebo infusions on alternating visits. The strongest overall sustained efficacy signal in this proof-of-concept study was seen with 0.16 mg/kg biweekly, while both pooled doses showed benefit at 24 hours.
Clinical Considerations
- This was a phase 2 proof-of-concept study with a small sample size and limited number of research sites.
- The article provides only partial eligibility details and refers to additional exclusion criteria in a supplementary appendix not included here.
- Onfasprodil is discussed as an investigational treatment option in this study rather than an established standard-of-care protocol.
- The trial used 1-sided testing for primary proof-of-concept comparisons, so findings should be interpreted as preliminary.
Bottom Line
The study population most relevant to onfasprodil was adults aged 18 to 65 years with DSM-5 major depressive disorder, a current episode lasting at least 8 weeks, MADRS 24 or higher, and failure of at least 2 adequate antidepressant trials including at least 1 in the current episode.
