A study in Healthy Volunteers to Compare the Amount of R406 in Blood When Given Different Formulations of Fostamatinib.

An Open-label, Single-center, Randomized, 4-way Crossover Study to Assess the Bioequivalence of R406 in Healthy Volunteers when 100 and 150mg of Fostamatinib are Administered as the 13% Drug-loaded Tablet Versus the 38% Drug-loaded Tablet.

Treatment sequences will be determined using two 2-2 crossover designs in sequence, 1 for treatments A and B, and 1 for treatments C and D. The order of the designs containing AB/BA and CD/DC within the overall design, as well as the order of treatments within each design, will be randomized. This gives a total of 8 possible treatment sequences as follows: ABCD, ABDC, BACD, BADC, CDAB, CDBA, DCAB, DCBA.

Inclusion Criteria:

• Males and nonlactating, non childbearing potential females from 18 to 55 years, inclusive and with a weight of at least 50 kg and BMI between 18 and 30 kg/m2, inclusive
• Females must have a negative pregnancy test at screening and on admission to the study center of each period, must not be lactating and must be of non childbearing potential
• Non childbearing potential can be confirmed by being postmenopausal defined as amenorrhea for a least 12 months following cessation of all exogenous hormonal treatments and with FSH and LH levels in the laboratory-defined postmenopausal range
• Non childbearing potential can be confirmed by documentation of irreversible surgical sterilization by hysterectomy, bilateral oophorectomy, or bilateral salpingectomy but not tubal ligation.

Exclusion Criteria:

• History of any clinically significant disease or disorder, including GI, hepatic or renal disease, or any other condition known to interfere with absorption, distribution, metabolism, or excretion of drugs
• Any positive result on screening for serum hepatitis B surface antigen, hepatitis C antibody, and human immunodeficiency virus (HIV) antibody
• Known or suspected history of drug abuse, as judge by the investigator
• Any clinically significant abnormalities on 12-lead ECG as judged by the Investigator
• Current smokers, or those who have smoked, used nicotine-containing products, or used smoking cessation treatments within the previous 1 month prior to enrollment