Eligibility Criteria:
Inclusion Criteria:
* Healthy as defined as being free from clinically significant illness or disease as determined by a responsible and experienced physician, based on a medical evaluation including medical history, physical examination, vital sign, laboratory tests and ECG. Rationale: Set for the appropriate selection of healthy males
* Japanese healthy male between 20 and 55 years of age inclusive, at the time of signing the informed consent. Rationale: Set for the appropriate evaluation of safety and pharmacokinetics of GSK1550188 in healthy Japanese males
* Body weight greater than and equal to 50.0 kg and BMI within the range 18.5 more than and equal to - less than 25.0 kg/m2. Rationale: To include those who have a standard figure based on the obesity criteria of the Obesity Association in Japan, these ranges are established
* Non-smoker or ex-smoker having ceased smoking for at least 6 months. Rationale: Set for the appropriate evaluation of safety and pharmacokinetics of GSK1550188 in healthy Japanese males
* AST, ALT, alkaline phosphatase and total bilirubin less than and equal to ULN at screening. Rationale: Set for the appropriate evaluation of safety and pharmacokinetics of GSK1550188 in healthy Japanese males
* Capable of giving written informed consent, which includes compliance with the requirements and restrictions listed in the consent form. Rationale: Set in consideration of ethics of the study in accordance with GCP.
* Single QTc \[QTcF\] less than 450 msec. Rationale: Set for the appropriate evaluation of safety and pharmacokinetics of GSK1550188 in healthy Japanese males
Exclusion Criteria:
* A positive test for syphilis, Hepatitis B surface antigen, Hepatitis B surface antibody, Hepatitis B core antibody, or positive Hepatitis C antibody, HIV antigen /antibody, HTLV-1 antibody at screening. Rationale: Set for the appropriate selection of healthy subjects and in consideration of safety of the staff that handle or measure the blood samples.
* A positive pre-study drug screen at screening. Rationale: To exclude inappropriate subjects for the evaluation of the safety and pharmacokinetics of GSK1550188.
* History of regular alcohol consumption exceeding, on average, 14 drinks/week for men (1 drink = 5 ounces (150 mL) of wine or 350 mL of beer or 1.5 ounces (45 mL) of 80 proof distilled spirits) within 6 months of screening. Rationale: To exclude inappropriate subjects for the evaluation of the safety and pharmacokinetics of GSK1550188.
* The subject had participated in a clinical study or post-marketing study with an investigational or a non-investigational product during the previous 4 months preceding the administration of study medication of this study. Rationale: To exclude inappropriate subjects for the evaluation of the safety and pharmacokinetics of GSK1550188.
* Exposure to more than four new chemical entities within 12 months prior to the dosing day. Rationale: To exclude inappropriate subjects for the evaluation of the safety and pharmacokinetics of GSK1550188.
* The subject planned to concurrently participate in another clinical study or post-marketing study. Rationale: To exclude inappropriate subjects for the evaluation of the safety and pharmacokinetics of GSK1550188.
* Use of prescription or non-prescription drugs, including vitamins, herbal and dietary supplements within 14 days or 5 half-lives (whichever is longer) prior to the administration of study medication. Rationale: To exclude inappropriate subjects for the evaluation of the safety and pharmacokinetics of GSK1550188.
* History of sensitivity to any of the study medications, or components thereof or a history of drug or other allergy excluding pollen allergy without current symptoms. Rationale: To exclude inappropriate subjects for the evaluation of the safety and pharmacokinetics of GSK1550188.
* Where participation in the study would result in donation of blood or blood products in excess of 400 mL within 4 month or 200 mL within 2 months.
* Unwillingness or inability to follow the procedures outlined in the protocol. Rationale: Set to secure study quality
* Subject is mentally or legally incapacitated. Rationale: Set to secure study quality
* Subjects with ECG results considered clinically significant by the investigator. Rationale: To exclude inappropriate subjects for the evaluation of the safety and pharmacokinetics of GSK1550188.
* Subjects with a supine systolic blood pressure less than 90 mmHg or greater than140 mmHg and/or a supine diastolic blood pressure less than 55 mmHg or greater than 90 mmHg and/or systolic blood pressure drop from supine to standing of greater than 30 mmHg. Rationale: Set in consideration of subjects' safety related to the IV route of administration.
* Immunoglobulin (M, A, G) level is less than LLN at screening. Rationale: To exclude inappropriate subjects for the evaluation of the safety and pharmacokinetics of GSK1550188.
* History of anaphylactic reaction to any food, drug, or insect bite/sting. Rationale: To exclude inappropriate subjects for the evaluation of the safety and pharmacokinetics of GSK1550188.
* History of allergic reaction to parenteral administration of contrast agents, foreign proteins, or monoclonal antibodies. Rationale: To exclude inappropriate subjects for the evaluation of the safety and pharmacokinetics of GSK1550188.
* History of B cell targeted therapy (rituximab, other anti-CD20agents, anti-CD22 \[epratuzumab\], anti-CD52 \[alemtuzumab\], BLyS-receptor fusion protein \[BR3\], TACI-Fc, LY2127399 \[anti-BAFF\] or GSK1550188) at any time. Rationale: To exclude inappropriate subjects for the evaluation of the safety and pharmacokinetics of GSK1550188.
* History of any infection requiring hospitalization or treatment with antivirals or antibiotics, or vaccination within 30 days prior to administration of study medication. Rationale: To exclude inappropriate subjects for the evaluation of the safety and pharmacokinetics of GSK1550188.