Safety and Tolerability of XmAb®7195 in Adult Healthy Volunteers and Adult Subjects With a History of Allergic Rhinitis and/or Allergic Conjunctivitis and/or Atopic Dermatitis

Inclusion Criteria:

- Adult males and females 18 to 50 years of age

- Parts 1 and 3: Healthy subjects with no clinically significant abnormality identified
on medical or laboratory evaluation and no history of any clinically significant
disorder, condition, or disease that would pose a risk to subject safety or interfere
with the study evaluation, procedures, or completion;

- Part 2: Otherwise healthy male and female subjects with a history of allergic
rhinitis and/or allergic conjunctivitis and/or atopic dermatitis with an elevated
serum IgE

- Subjects who are able and willing to give written informed consent;

- Subjects who have the ability to complete all study assessments;

- Subjects who are willing to forego other forms of experimental treatment during the
study.

Exclusion Criteria:

- Subjects who have a clinically relevant history or presence of respiratory,
gastrointestinal, renal, hepatic, hematological, lymphatic, neurological,
cardiovascular, psychiatric, musculoskeletal, genitourinary, immunological,
dermatological, connective tissue diseases, or disorders (other than allergic
rhinitis and/or conjunctivitis and/or atopic dermatitis in Part 2) that would pose a
significant risk to subject safety or significantly interfere with the study
evaluation, procedures, or completion

- Subjects who are positive for hepatitis B surface antigen (HBsAg), hepatitis C virus
(HCV) antibody and/or human immunodeficiency virus (HIV) Type I or Type II tests at
Screening;

- Subjects who do not agree to use medically acceptable methods of contraception (as
defined in the protocol);

- Subject is pregnant or breast feeding, or planning to become pregnant within 3 months
of administration of XmAb7195;

- Subjects who have used any investigational drug in any clinical trial within 8 weeks
prior to admission (Day -1), or have used an experimental monoclonal antibody;

- Subjects with prior exposure to a monoclonal antibody;

- Subjects with a history of anaphylaxis;

- Subjects who have received live vaccines ≤ 3 months from Screening;