The purpose of this study is to investigate what side effects the new compound LEO 158968 might cause and how well it is tolerated when it is used by healthy participants. It will also investigate how quickly and to what extent LEO 158968 is distributed and eliminated from the body and if LEO 158968 causes the body to make antibodies.

In the single ascending dose (SAD) cohorts, participants will receive escalating doses of LEO 158968 if the safety and tolerability results of the initial participants up to 48 hours (or 4 days for SC dosing) following dosing are acceptable to the Investigator.

In the multiple ascending dose (MAD) cohorts, the dose of LEO 158968 will be determined based on results derived from the earlier SAD cohorts and additional preclinical data from a 5-week good laboratory practice (GLP) cynomolgus monkey toxicology study.

Inclusion Criteria:

1. Age: 18 to 60 years, inclusive, at screening
2. Sex: Male or female
3. Body mass index: 18.0 kg/m^2 to 32.0 kg/m^2, inclusive, at screening
4. Health status: In good health as judged by the Investigator based on medical history, physical examination, electrocardiogram (ECG), hematology, biochemistry, and urinalysis.

Exclusion Criteria:

A participant who meets any of the following exclusion criteria will not be eligible for inclusion in the study:

1. Male participants sexually active with a woman of childbearing potential who are not willing to use a barrier method of contraception (eg, condom) from the time of first dose of investigational medicinal product (IMP) until 16 weeks after the last dose, in conjunction with this female partner using a highly effective form of contraception.
2. Female participants who are pregnant, lactating, or planning to become pregnant during the time of the trial.
3. Participants with any surgical or medical condition which might significantly alter the distribution, metabolism, or excretion of any drug.
4. Positive polymerase chain reaction (PCR) test for coronavirus disease-19 (COVID-19) on Day -1, or contact with COVID-19 positive (or suspected) persons within 14 days prior to first dose.
5. ECG with QT-interval corrected for heart rate (QTc) using Fridericia's formula (QTcF) >450 msec for men, >460 msec for women, confirmed by repeat measurement at screening.
6. Treatment with any prescribed or nonprescribed systemic or topical medication within 7 days prior to the first dose of IMP (excluding paracetamol; including herbal remedies), unless, in the opinion of the Investigator and the Sponsor, the medication will not interfere with the trial procedures or compromise safety.