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Introduction: Mirabegron is a new once-daily, oral treatment for management of overactive bladder (OAB) that is approved in USA, EU and Japan. It activates β3 adrenoceptor to facilitate bladder filling and reduce mean micturition frequency with better safety profile than current treatment of antimuscarinic drugs., Areas Covered: The following article reviews the information available from published randomized trials on the metabolism and pharmacokinetics mirabegron. The reader will gain better insight into the variability in plasma exposure of mirabegron due to various causes. Propensity for drug interactions with mirabegron is low as its clearance involves multiple metabolic and excretory pathways. Mirabegron is generally well tolerated, but its pharmacokinetics is altered by dose and gender with implications for cardiovascular toxicity., Expert Opinion: Mirabegron is a first-in-class of β3 adrenoceptor agonists that could offer an alternative to antimuscarinics for OAB patients. The marketed dose of 50 mg achieves primary efficacy endpoints but causes only modest improvement over placebo in terms of daily incontinence and voiding episodes. Involvement of saturable efflux transporters is indicated in oral bioavailability of mirabegron. It is well tolerated with hypertension, nasopharyngitis, urinary tract infection and headache being the most common side effects.

Purpose: On June 28, 2006, the U.S. Food and Drug Administration approved dasatinib (Sprycel; Bristol-Myers Squibb), a new small-molecule inhibitor of multiple tyrosine kinases, for the treatment of adults with chronic phase, accelerated phase, or myeloid or lymphoid blast phase chronic myeloid leukemia (CML) or Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph(+) ALL) with resistance or intolerance to prior therapy including imatinib. This summary reviews the database supporting this approval., Experimental Design: Four single-arm multicenter studies supported the efficacy and safety of dasatinib. The primary efficacy end point in chronic phase CML was major cytogenetic response. The primary end point in accelerated phase, myeloid phase, and lymphoid blast phase CML, and Ph(+) ALL was major hematologic response., Results: The four studies combined enrolled 445 patients. In patients with chronic phase CML, the major cytogenetic response rate was 45% with a complete cytogenetic response rate of 33%. Major hematologic response rates in patients with accelerated phase CML, myeloid CML, lymphoid blast CML, and Ph(+) ALL were 59%, 32%, 31%, and 42%, respectively. Median response durations in chronic phase, accelerated phase, and myeloid phase CML had not been reached. The median durations of major hematologic response were 3.7 months in lymphoid blast CML and 4.8 months in Ph(+) ALL. Common toxicities with dasatinib included myelosuppression, bleeding, and fluid retention., Conclusions: This report describes the Food and Drug Administration review supporting the approval of dasatinib for CML and Ph(+) ALL based on the rates and durability of cytogenetic and hematologic responses.