Inclusion Criteria:

-

1. Male or female, ≥18 and ≤65 years of age, with BMI >18.5 and <32.0 kg/m2. 2.
Healthy as defined by:

1. The absence of clinically significant illness and surgery within 4 weeks prior
to study drug administration.

2. The absence of clinically significant history of neurological, endocrine,
cardiovascular, respiratory, hematological, immunological, psychiatric,
gastrointestinal, renal, hepatic, and metabolic disease. Fully resolved basal
cell carcinoma (BCC) and squamous cell carcinoma (SCC) are acceptable.

3. Females of non-childbearing potential must be:

1. post-menopausal (spontaneous amenorrhea for at least 12 months prior to dosing)
with confirmation by documented FSH levels 40 mIU/mL or greater; or

2. surgically sterile (bilateral oophorectomy or hysterectomy) at least 3 months
prior to dosing.

4. Sexually active females of childbearing potential and non-sterile males
must be willing to use an acceptable contraceptive method throughout the
study as detailed in section 8.1.

5. Male participants must be willing not to donate sperm for 90 days and
female participants must be willing not to donate eggs for 30 days after
dosing.

6. Willing to abstain from alcohol, tobacco, and illicit drug use for 48
hours prior to admission to the CRU (Day -1) and during the inpatient
period.

7. Non-tattooed, clear injection site (i.e., absence of dermatologic
conditions, such as scarring or rash, that may impact the ability to
assess injection site reactions) suitable for IV or IM injection and
monitoring in the opinion of the Investigator.

8. Able to understand the study procedures and provide signed informed
consent to participate in the study

Exclusion Criteria:

1. Any clinically significant abnormal finding at physical examination.

2. Clinically significant abnormal laboratory test results or positive
serology test results for HBsAg, HCV antibody, or HIV antigen and
antibody, or QuantiFERON®-TB test at screening. Per Investigator's
discretion, a single repeat for safety laboratory assessment to confirm
initial result and trending is allowed per investigator's discretion.

3. Positive pregnancy test or lactating female participant.

4. Positive urine drug screen, or alcohol breath test.

5. History of significant allergic reactions (e.g., anaphylactic reaction,
hypersensitivity, angioedema) to any drug, in the opinion of investigator.

6. Clinically significant ECG abnormalities or vital signs abnormalities
(systolic BP lower than 90 or over 140 mmHg, diastolic BP lower than 40 or
over 90 mmHg, HR less than 40 or over 100 bpm, or RR less than 10 or over
22 bpm) at screening.

7. History of drug abuse within 1 year prior to screening or recreational use
of soft drugs (such as marijuana) within 1 month or hard drugs (such as
cocaine, phencyclidine [PCP], crack, opioid derivatives including heroin,
and amphetamine derivatives) within 3 months prior to screening. per
investigator's discretion, a single repeat for drug abuse urine test in
the event of a false positive is allowed.

8. History of alcohol abuse within 1 year prior to screening or regular use
of alcohol within 6 months prior to screening that exceeds 14 units for
women and 21 units for men of alcohol per week (1 unit = 200 mL of beer
5%, 83 mL of wine 12%, or 25 mL of distilled alcohol 40%).

9. Participants who smoke more than 10 cigarettes per day or the equivalent
per week.

10. History of rare hereditary sucrose intolerance (e.g., genetic
sucrose-isomaltase deficiency (GSID).

11. History of a known or suspected respiratory system disorder including, but
not limited to, cystic fibrosis, interstitial lung disease, reactive
airway disease, emphysema, chronic bronchitis, pulmonary hypertension,
COPD, or asthma (participants with childhood asthma can be included in the
study).

12. Diagnosis or suspected diagnosis of immunodeficiency or autoimmune
diseases, or undergoing immunosuppressive therapy such as anticancer
chemotherapy or radiotherapy before the study, or has received systemic
corticosteroid treatment (topical corticosteroids are acceptable) within
the past 120 days before dosing.

13. Poor peripheral venous access for Cohorts 1a, 2a, and 3a.

14. Fever (≥ 38.0°C) within 14 days before study drug administration.

15. Positive Corona Virus Disease of 2019 (COVID-19) test at admission to the
CRU.

16. Vaccination (including COVID-19 vaccine) within 30 days prior to
administration of PDI204.

17. Known or suspected intolerance or hypersensitivity to any biologic
medication or known allergies or clinically significant reactions to human
proteins, mAbs or antibody fragments, or to any components of the
formulation of PDI204 and its excipients used in this study.

18. History of bleeding disorders or clotting disorders (e.g., hemophilia,
thrombocytopenia) or those with a history of easy bruising or bleeding who
may be at a higher risk for hematoma at the injection site.

19. Participants who had close contact (without PPE) as defined by the Centers
for Disease Control and Prevention (CDC) in the past 14 days to someone
diagnosed with SARS-CoV-2 infection or COVID-19 within 10 days of the
close contact. Participants may be rescreened after 14 days provided that
they remain asymptomatic.

20. Participants who have been infected by COVID-19, within 30 days prior to
the drug administration.

21. Has known active infection with influenza or other non-SARS-CoV-2
respiratory pathogen, confirmed by a diagnostic test.

22. Previous infusion-related reaction, or severe adverse reaction following
administration of a mAb.

23. Use of medications within the timeframes specified in section 8.2.

24. Participation in a clinical research study involving the administration of
an investigational or marketed drug (including mAbs) or device within 30
days (or 5 half-lives since last receipt of an investigational drug,
whichever is longer) prior to the first dosing, administration of a
biological product in the context of a clinical research study within 90
days prior to the first dosing, or concomitant participation in an
investigational study involving no drug or device administration.

25. Donation of serum within 7 days prior to dosing or donation or loss of 500
mL or more of whole blood within 30 days prior to screening.

26. Any reason which, in the opinion of the Investigator, would prevent the
subject from participating in the study.