This is the first multiple-dose study in humans with PRA-027. This study will provide an assessment of the safety, tolerability, pharmacokinetics (how the drug is absorbed, metabolized and excreted by the body) and pharmacodynamics (a measure of whether the drug is active in the body) of PRA-027 after administration of 28 days of oral doses in women of childbearing potential (cycling) or postmenopausal women.