This is an open-label, two-part, single-center, first in human (FIH), single ascending dose (SAD) study to assess the effects of single doses of ASLAN004 when administered to healthy subjects. The objective of this study is to evaluate the safety, tolerability, and Pharmacokinetics (PK) of ASLAN004 in healthy subjects.

The plan is to enroll between 38 to 50 subjects at 1 study center.

The study is divided into 2 parts:

Part A is designed as a SAD study using intravenous (IV) administration of ASLAN004, as a single mg/kg IV dose and will consist of up to 6 IV cohorts.

Part B is designed as a parallel SAD study using subcutaneous (SC) administration of ASLAN004, as a single fixed milligram SC dose and will consist of up to 4 SC cohorts.

All cohorts will have sentinel dosing with the first subject of each cohort being spaced with adequate observation time of 24 to 48 hours before dosing the remaining subjects in the cohort.

All subjects would be follow up for up to 85 days from the last dosing day.

Inclusion Criteria:

1. Must be able to sign informed consent form
2. Male and female subjects who are of legal age
3. Healthy, BMI 18.5 to 30 kg/m2
4. Normal or clinically acceptable clinical laboratory value and ECG results

Exclusion Criteria:

1. History of hypersensitivity reaction
2. Have food and/or topical allergies
3. Have recent history of conjunctivitis
4. Have active or history of psoriasis