Clinical assessment of lurasidone benefit and risk in the treatment of bipolar I depression using number needed to treat, number needed to harm, and likelihood to be helped or harmed

Abstract

BackgroundPrior to recent FDA approval of lurasidone for treatment of bipolar depression there were only two approved treatments for this condition (quetiapine and olanzapine–fluoxetine combination), and these were as likely to provide therapeutic benefit as adverse effects. We assessed the efficacy, safety, and tolerability of lurasidone for major depressive episodes associated with bipolar I disorder, using number needed to treat (NNT, for benefits), number needed to harm (NNH, for harms), and likelihood of being helped or harmed (LHH, ratio of NNH to NNT, for trade-offs between benefits vs. harms). MethodsData was collected from two 6-week multicenter, randomized, double-blind, placebo-controlled, flexibly-dosed acute bipolar I depression studies, one using lurasidone monotherapy at 20–60mg/d or 80–120mg/d, and the other using lurasidone 20–120mg/d adjunctive to lithium or valproate. The NNT or NNH was calculated for lurasidone vs. placebo for the following dichotomous outcomes: response (≥50% reduction from baseline on Montgomery Asberg Depression Rating Scale (MADRS) total score); remission (final MADRS total score ≤12); discontinuation due to an adverse event (AE); weight gain ≥7% from baseline; incidence of spontaneously reported AEs; and incidence of total cholesterol ≥240mg/dl, low-density lipoprotein cholesterol ≥160mg/dl, fasting triglycerides ≥200mg/dl and glucose ≥126mg/dl post-baseline. ResultsNNT vs. placebo for response was 5 for lurasidone monotherapy (both dose ranges) and 7 for adjunctive therapy. NNT vs. placebo for remission for lurasidone monotherapy was 6 for 20–60mg/d and 7 for 80–120mg/d and 7 for adjunctive lurasidone. NNH vs. placebo for discontinuation due to an AE for lurasidone monotherapy was 642 for 20–60mg/d and −181 for 80–120mg/d, and for adjunctive lurasidone was −54 (negative NNH denotes an advantage for lurasidone). Lurasidone was not associated with any clinically meaningful mean weight or metabolic changes compared to placebo; NNH vs. placebo for weight gain ≥7% was 29 for 20–60mg/d and 5550 for 80–120mg/d and 42 for adjunctive lurasidone. The three most frequently occurring AEs with the largest difference in incidence for lurasidone vs. placebo were nausea, akathisia, and somnolence, with NNH values for lurasidone vs. placebo ranging from 11 (nausea with lurasidone monotherapy 80–120mg/d) to 130 (somnolence with lurasidone monotherapy 20–60mg/d). LHH was substantially and consistently >1 (indicating benefit being more likely than harm) when contrasting response or remission vs. AEs or weight gain. LimitationsAdditional studies, including longer-term and open-label, “real world” data is needed to confirm the results reported here. ConclusionsNNT, NNH, and LHH help quantify relative benefits (efficacy) and harms (side effects), thus placing lurasidone findings in research studies into clinical perspective. Lurasidone, compared to other treatments approved for bipolar depression, yielded comparable benefits (all had single-digit NNT vs. placebo for response or remission), and less risk of harm (double-digit or greater NNHs with lurasidone compared to single-digit NNHs for sedation with quetiapine and for ≥7% weight gain with olanzapine–fluoxetine combination), and thus a substantially more favorable LHH (> or >>1) with lurasidone monotherapy and adjunctive therapy, compared to quetiapine and olanzapine–fluoxetine combination (LHH<or ~1).