GRC 27864 First in Man, Single Ascending Dose Study in Healthy Volunteers

Inclusion Criteria: 1. Male or female healthy subjects, age ≥18 to ≤55 years (≥65 years for elderly subjects study) at the time of informed consent 2. Body mass index between 18.5 and 32.0 kilograms per square meter (kg/m2), inclusive 3. Female subjects who are of child-bearing potential or had tubal ligation must agree to use highly effective methods of contraception 4. Male subjects whose partners are of child-bearing potential or had tubal ligation must also agree to use two highly effective method of contraception Exclusion Criteria: 1. Subjects with inherited or acquired disorders in platelet function, bleeding or coagulation. 2. Presence of any clinically relevant acute or chronic disease which could interfere with the subject safety during the clinical study, expose the subject to undue risk. 3. Veins unsuitable for repeat venepuncture. 4. Presence of clinical laboratory test values judged clinically significant by the investigator. 5. Positive test results for hepatitis B surface antigen (HBsAg), hepatitis C virus antibodies (HCVAb) or human immunodeficiency virus (HIV)-1 and/or -2 antibodies at screening. 6. History or presence of drug abuse at screening or upon admission to the CRU. 7. Participation in another clinical study with an experimental drug within 3 months before the first administration of the IMP. 8. Any psychological, emotional problems, any disorders or resultant therapy that is likely to invalidate informed consent, or limit the ability of the subject to comply with the Clinical Study Protocol requirements.