The primary object in this research study is to investigate the safety and tolerability of ZP9830 in healthy study participants, and in addition, the study will investigate how ZP9830 works in the body (pharmacokinetics, PK and pharmacodynamics, PD) compared to placebo.

SAD Part A: Participants will receive 1 dose either ZP9830 or placebo as an injection under the skin (subcutaneous, s.c.), and safety and PK will be assessed.

SAD Part B: Participants will receive 1 dose either ZP9830 or placebo as an injection under the skin (subcutaneous, s.c.), and safety, PK and PD will be assessed.

SAD Part C: Participants will receive 1 dose either ZP9830 or placebo as intravenous (i.v.) dose, and safety and PK will be assessed.

MAD Part: Participants will receive multiple doses of either ZP9830 or placebo as an injection under the skin (subcutaneous, s.c.), and safety and PK will be assessed.

Inclusion Criteria:

• Healthy participants.
• 18-45 years of age (inclusive).
• Body weight ≥50 kg.
• SAD part B only: Fitzpatrick skin type I-III (Caucasian).
• C-reactive protein ≤10 mg/L.
• Further inclusion criteria apply.

Exclusion Criteria:

• Evidence of any active or chronic disease or condition that could interfere with, or for which the treatment of it might interfere with, the conduct or the interpretation of the results of the trial, or that would pose an unacceptable risk to the subject in the opinion of the Investigator [following a detailed medical history, physical examination, vital signs (systolic and diastolic blood pressure, pulse rate, body temperature) and 12-lead ECG].
• Any disease associated with immune system impairment, including immune mediated diseases and transplantation patients.
• Any confirmed significant allergic reactions (urticaria or anaphylaxis) to insect bites.
• History of neurological disorders including neuropathy, as judged by the investigator.
• Any confirmed significant allergic reactions (urticaria or anaphylaxis) against any drug or food (in particular any level of severity of allergy to shellfish), or multiple drug allergies (non-active hay fever is acceptable).
• Further exclusion criteria apply.