A Phase 1 Study of CDX-0159

CDX-0159 is a humanized monoclonal antibody that binds to a protein called KIT that is expressed on mast cells.

This study will evaluate the safety, pharmacokinetics, and pharmacodynamics of CDX-0159 in healthy subjects.

Key Inclusion Criteria:

• An informed consent signed and dated by the subject.
• Healthy volunteer aged 18-55.
• In generally good health and without significant medical conditions based on physical exam, ECG, and laboratory test results.
• Body mass index (BMI) ≥ 18.5 kg/m2 to ≤ 30 kg/m2
• No medication other than mild analgesics, vitamins and mineral supplements or, oral contraceptives
• Both males and females of child bearing potential must agree to use a medically accepted contraceptive regimen during study and up to 150 days afterwards.
• Not a current smoker (or regular user of any nicotine containing product).
• Willing to follow all study rules

Key Exclusion Criteria:

• Women who are pregnant or nursing
• History of anaphylaxis, food allergies, or allergies (chronic or seasonal) requiring prescription medication
• Autoimmune disorders requiring more than topical medication
• History of asthma requiring the use of inhaled medication within the past 5 years.
• Vaccination with live vaccines within 4 weeks prior to study drug administration (subjects must agree to avoid vaccination during the study).
• Positive urine test for alcohol and drugs of abuse.

Other Protocol defined inclusion and exclusion criteria could apply.