A Study of the Effects of Food and Age on Danicopan

Inclusion Criteria: 1. Young adult males or females, between 18 and 55 years of age (Part 1 only). 2. Elderly male participants aged ≥ 65 years of age at screening (Part 2 only). 3. Body mass index in the range of 18.0 to 32.0 kilograms (kg)/meter squared, inclusive, with a minimum body weight of 50.0 kg at screening. 4. No clinically significant history or presence of electrocardiogram findings at screening. 5. Non-sterile male participants must agree to abstinence or use a highly effective method of contraception. 6. Female participants of childbearing potential must either agree to abstinence or to use, with their male partner, a highly effective method of contraception (Part 1 only). Exclusion Criteria: 1. Clinically significant laboratory abnormalities. 2. Pregnant or lactating (Part 1 only). 3. History of any medical or psychiatric condition or disease that might limit the participant's ability to complete or participate in this clinical study, confound the results of the study, or pose an additional risk to the participant by their participation in the study. 4. History or presence of drug or alcohol abuse within previous 2 years, current tobacco user, and positive drugs-of-abuse or alcohol screen at screening or Day -1 of Period 1. 5. History of meningococcal infection, or a first-degree relative with a history of meningococcal infection. 6. Body temperature ≥ 38.0°Celsius at screening or prior to (first) dosing in Period 1 or history of febrile illness, or other evidence of infection, within 14 days prior to (first) dosing. 7. History of procedures that could alter absorption or excretion of orally administered drugs. 8. A history of significant multiple and/or severe allergies or has had an anaphylactic reaction or significant intolerability to prescription or non-prescription drugs. 9. Major surgery within previous 4 weeks. 10. Participation in any other investigational study drug trial in which receipt of an investigational study drug occurred within 5 half-lives (if known) or 30 days before (first) dosing, whichever is longer. 11. Donation of whole blood from 3 months prior to (first) dosing or of plasma from 30 days before (first) dosing, receipt of blood products within 6 months prior to (first) dosing, or receipt of a vaccine within 30 days prior to (first) dosing.