The purpose of this study is to evaluate the safety, tolerability, and pharmacokinetics (PK) of JNJ-77242113 after single ascending oral dose administration as an immediate-release (IR) tablet formulation in healthy Japanese participants and after single oral dose administration as an IR tablet formulation in healthy Chinese participants; and as a delayed release (DR) tablet formulation in healthy Japanese participants.

Inclusion Criteria:

• For Parts 1 and 3: Japanese male or female of non-childbearing potential, who have parents and maternal and paternal grandparents who are of Japanese ethnicity
• For Part 2: Chinese male or female of non-childbearing potential, who have parents and maternal and paternal grandparents who are of Chinese ethnicity
• Healthy on the basis of physical examination, medical history, vital signs, and 12-lead electrocardiogram (ECG) performed at screening. If there are abnormalities, they must be consistent with the underlying illness in the study population. This determination must be recorded in the participant's source documents and initialed by the investigator
• Body weight not less than 50 kilograms (kg) and body mass index within the range 18 and 30 kilograms per meter square (kg/m^2) (inclusive)
• Blood pressure (after the participant is supine for 5 minutes) between 90 and 140 millimeters of mercury (mmHg) systolic, inclusive, and no higher than 90 mmHg diastolic. If blood pressure is out of range, up to 2 repeated assessments are permitted

Exclusion Criteria:

• History of malignancy before screening (exceptions are squamous and basal cell carcinomas of the skin and carcinoma in situ of the cervix, or malignancy, which is considered cured with minimal risk of recurrence)
• Known allergies, hypersensitivity, or intolerance to JNJ-77242113 or its excipients
• Use of a live vaccine within 30 days prior to screening or anticipated need for a live vaccine during the study or for 30 days following the dose of study drug
• Received an experimental drug (including investigational vaccines) or used an experimental medical device within 1 month or within a period less than 10 times the drug's half-life, whichever is longer, before the dose of the study intervention is scheduled
• Test positive for human immunodeficiency virus (HIV)-1 and 2 antigen/antibodies, test positive for hepatitis C antibodies, test positive for syphilis, or test positive for hepatitis B virus (HBV) infection at screening

The data sharing policy of the Janssen Pharmaceutical Companies of Johnson & Johnson is available at www.janssen.com/clinical-trials/transparency. As noted on this site, requests for access to the study data can be submitted through Yale Open Data Access (YODA) Project site at yoda.yale.edu