Intra-Cellular Therapies had quite a journey toward an FDA decision on its antipsychotic contender. It involved mixed clinical data, a canceled advisory committee meeting and a three-month review extension. That journey finally came to an end Monday, as the agency approved a 42 mg daily dose of Caplyta (lumateperone) for the treatment of schizophrenia. The company said it expects to launch the drug late in the first quarter next year. Management didn’t unveil its sales force size, but it has “identified the top 15,000 to 20,000 high prescribers of antipsychotics, who treat schizophrenia, representing the majority of the market potential, and we are confident that we've sized the sales force to have a highly competitive promotional effort,” the company’s Chief Commercial Officer, Mark Neumann, said during the company’s third-quarter conference call in November.The green light caps off a twisted FDA review path, which previously hinted at a possible rejection. Caplyta beat placebo on improving schizophrenia symptom severity as measured by a metric known as the Positive and Negative Syndrome Scale in two placebo-controlled trials. But one phase 3 study, dubbed ITI-007-302 and involving 696 patients, failed back in 2016, as the drug—at both the 20-mg and 60-mg doses—didn’t top placebo on the score. Then, Intra-Cellular’s stock suffered again in July when the FDA called off an advisory panel meeting, citing “new information regarding the application.” The company said at the time that the agency was looking at information from non-clinical studies. To investors, that cancellation was interpreted as low FDA confidence in the drug—so low that it didn't even require an open discussion. RELATED: FDA calls off AdComm for Intra-Cellular's schizophrenia prospect To further complicate investor sentiment, the FDA in August extended its review time by three months, citing the need to look over preclinical data. However, after going through similar historical events, Jefferies analysts in November noted that most new drug applications that had decision extensions actually ended up with FDA approvals. Caplyta is designed to target three neurotransmitters in the brain—serotonin, dopamine and glutamate—that are implicated in several neuropsychiatric disorders. Citing the fact that patients often cycle through several antipsychotics, Neumann said in November that payers recognize Caplyta’s “favorable safety and tolerability profile in addition to a unique mechanism of action.” Besides schizophrenia, Intra-Cellular is also eyeing Caplyta use in other indications, such as bipolar disorder and major depressive disorder. In two phase 3 studies for major depressive episodes associated with bipolar I or bipolar II disorder, the drug also showed mixed results, as one met its primary endpoint while another missed.