A Research Study Investigating How NNC0385-0434 is Tolerated in People With or Without High Cholesterol Levels

Inclusion Criteria: Healthy volunteers: * Body mass index between 20.0 kg/m\^2 and 35.0 kg/m\^2 (both inclusive). * Male subjects. * Aged 18-55 years (both inclusive) at the time of signing informed consent. Patients with hypercholesterolaemia: * Body mass index between 20.0 kg/m\^2 and 35.0 kg/m\^2 (both inclusive). * Male subjects. * Aged 18-70 years (both inclusive) at the time of signing informed consent. * Stable treatment with high- or moderate-intensity statin defined as total daily dose level of rosuvastatin equal to or above 10 mg, atorvastatin equal to or above 10 mg, simvastatin equal to or above 20 mg, pravastatin equal to or above 40 mg, lovastatin equal to or above 40 mg, fluvastatin equal to or above 80 mg, or pitavastatin equal to or above 1 mg for at least 30 days prior to enrolment and expected to remain on this dose for the remainder of the trial. Exclusion Criteria: Healthy volunteers: * Male subjects who are not surgically sterilised (vasectomy) and are sexually active with female partner(s) and not using condom with spermicide combined with an effective method of contraception for their female partner(s) in the period from randomisation visit (V2) until 10 weeks following administration of the investigational medical product. * Any disorder which in the Investigator's opinion might jeopardise subject's safety, evaluation of results, or compliance with the protocol. Patients with hypercholesterolaemia: * Male subjects who are not surgically sterilised (vasectomy) and are sexually active with female partner(s) and not using condom with spermicide combined with an effective method of contraception for their female partner(s) in the period from randomisation visit (V2) until 10 weeks following administration of the investigational medical product. * Any disorder which in the Investigator's opinion might jeopardise subject's safety, evaluation of results, or compliance with the protocol. * Current treatment with ezetimibe unless treatment has been with a stable dose for at least 30 days prior to enrolment and expected to remain on this dose for the remainder of the study. * History (as declared by the subject or reported in the medical records) of heart failure or clinically significant cardiac arrhythmia. * History (as declared by the subject or reported in the medical records) of myocardial infarction, unstable angina, coronary artery bypass graft, percutaneous coronary intervention, peripheral vascular or cerebrovascular disease within 12 months prior to enrolment * Planned surgery or revascularization at time of screening.