Lurasidone for the Acute Treatment of Adults with Schizophrenia: What is the Number Needed to Treat, Number Needed to Harm, and Likelihood to be Helped or Harmed?

Abstract

To describe the efficacy, safety and tolerability of lurasidone for the acute treatment of schizophrenia using the metrics number needed to treat (NNT) and number needed to harm (NNH). Study data were pooled from six Phase II and III, 6-week, randomized, placebo-controlled trials that were conducted to test the efficacy and safety of lurasidone for the acute treatment of schizophrenia. Included were the following interventions: fixed doses of lurasidone 20, 40, 80, 120 and 160 mg/d; haloperidol 10 mg/d; olanzapine 15 mg/d; quetiapine extended-release 600 mg/d; placebo. The following outcomes were assessed: responder rates as defined by a reduction of ≥20, 30, 40 or 50% from baseline on the Positive and Negative Syndrome Scale (PANSS) total score; study completion; discontinuation due to an adverse event (AE); weight gain ≥7% from baseline; incidence of spontaneously reported AEs; incidence of total cholesterol ≥240 mg/dL, low-density lipoprotein cholesterol ≥160 mg/dL, fasting triglycerides ≥200 mg/dL and glucose ≥126 mg/dL at endpoint. NNT for the efficacy outcomes were calculated after excluding one failed study. NNH for the safety/tolerability outcomes were calculated using all six studies. Likelihood of being helped or harmed (LHH) was also calculated to illustrate trade-offs between outcomes of improvement ≥30% on the PANSS vs. incidence of akathisia, nausea, sedation, somnolence and parkinsonism. NNT vs. placebo for PANSS reductions ≥30% were 6, 6, 7 and 4 for lurasidone doses of 40, 80, 120 and 160 mg/d, respectively, and 4 and 3 for olanzapine 15 mg/d and quetiapine extended-release 600 mg/d, respectively. Lurasidone was not associated with any statistically significant disadvantages over placebo for weight gain or metabolic abnormalities; NNH vs. placebo for weight gain ≥7% from baseline was 4 for olanzapine and 9 for quetiapine extended-release in contrast to a NNH for this outcome ranging from 43 to 150 for lurasidone 40-160 mg/d. The 5 most consistently encountered adverse events attributable to lurasidone were akathisia, nausea, sedation, somnolence and parkinsonism, with NNH vs. placebo for lurasidone 40-120 mg/d ranging from 6 (akathisia with 120 mg/d) to 30 (parkinsonism with 80 mg/d). Lurasidone 160 mg/d appeared better tolerated than doses of 40, 80 or 120 mg/d for akathisia, nausea, sedation or somnolence, with no NNH values for these adverse events for 160 mg/d vs. placebo being statistically significant. LHH was favorable for lurasidone when contrasting PANSS reductions vs. adverse events. NNT and NNH can help quantify efficacy, safety and tolerability outcomes and place lurasidone into clinical perspective. Advantages for lurasidone include a low propensity for weight gain and metabolic abnormalities. More commonly encountered adverse events include akathisia, nausea, sedation, somnolence and parkinsonism, but NNH values are generally in the double digits, reflecting an overall tolerable profile. Individual patient characteristics, values and preferences will need to be considered when selecting lurasidone over other antipsychotics.