A phase 1b clinical trial aimed to examine the tolerability and efficacy of NSI-189 was conducted in 2014 and the study paper is available recently for the exact study results. The proper dosage of the medication was suggested as well as its effect of being antidepressant and the ability of generating new brain cells.
The study was jointly carried out by several organizations including Massachusetts General Hospital, Harvard Medical School Clinical Trial, Network Institute and supported by Neuralstem the company that developed the compound for its medical function.
The phase 1b trial is a placebo controlled double blind one. As the original aim of the study is to probe the effect endurance and determine the best daily dose amount. In total 24 patients suffering from major depressive disorder were enrolled in the trial. They were assigned to three different amount of NSI-189 and correspondent placebo randomly for a period of 28 days, during which remote monitoring by checking their daily condition was applied. And there was a follow up monitor period of 56 days after the trial finished.
The NSI-189 amount taken by patients only differ in the frequency while keep the one time dose at 40mg. Some took only once a day, and some twice and others take the drug three times a day. Thus actually, the day amounts of NSI-189 given to them are 40mg, 80mg, and 120mg per day. With the help of Symptoms of Depression Questionnaire and Montgomery-Asberg Depression Scale test, over-round positive changes were presented both during the drug taken period and in the follow up days. Study also found that NSI-189 could be active in bodies about 17.4–20.5 hours and the three different doses pose no side effect on the patients’ condition. But there was no significant improvement while the dose increased to 120mg per day.
The main drawback of the phase 1b trial is that the registered sample number is too small and the information got from the study can’t be powerful enough to get the conclusion. For a more accurate result a phase II study is undergoing to find out more about the effect of NSI-189 on major depressive disorder.
The study paper of the phase 1b trial is available at Nature website and is titled as A Phase 1B, randomized, double blind, placebo controlled, multiple-dose escalation study of NSI-189 phosphate, a neurogenic compound, in depressed patients with the doi number being 10.1038/mp.2015.178