Phase 1 Study Involving SAB01 and Healthy Participants

A Phase 1, Randomized, Double Blind, Placebo-Controlled, Single Ascending Dose Study to Evaluate the Safety, Pharmacokinetics, and Pharmacodynamics of SAB01 in Healthy Participants

SAB01 is an investigational bispecific monoclonal antibody targeting mast cells. This first-in-human Phase 1 clinical trial evaluates the safety, pharmacokinetics, and pharmacodynamics of single ascending doses of SAB01 in healthy adult participants.

This is a first-in-human, randomized, double-blind, placebo-controlled, single ascending dose (SAD) study to evaluate the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of SAB01 administered subcutaneously (SC) and intravenously (IV) in healthy participants.

The design comprises 7 planned cohorts (6 SC and 1 IV) and up to 4 optional cohorts (up to 3 additional SC and up to 1 additional IV) for up to a maximum of 88 participants enrolled. The Safety Review Committee will oversee dose escalation.

Within each cohort, 8 participants will be randomized 6:2 to SAB01 or placebo

Optional cohorts may be added to evaluate select SC and IV dose levels selected based on emerging safety, PK, and PD data and Safety Review Committee review. IV dose levels will not exceed dose levels previously evaluated by SC administration.

Inclusion Criteria:

1. Provision of signed and dated ICF.
2. Stated willingness to comply with all study procedures and availability for the duration of the study.
3. Healthy adult male or female aged at least 18 years but not older than 55 years.
4. Body mass index (BMI) within 18.0 to 32.0 kg/m2 inclusive, and up to a maximum body weight of 100 kg at Screening.
5. Non- or ex smokers. Participants must not have used any tobacco products within 6 months prior to Screening. Participants who have discontinued smoking or the use of nicotine or nicotine-containing products for at least 3 months prior to Screening may be enrolled at the discretion of the Investigator
6. Have no clinically significant diseases captured in the medical history or evidence of clinically significant findings on the physical examination (including vital signs) and/or electrocardiogram (ECG), as determined by an Investigator
7. Have clinical laboratory values within the normal range or, if abnormal, deemed not clinically significant by the Investigator (following consultation with the Sponsor, as appropriate).
8. Serum tryptase levels within clinically accepted normal ranges (ie, ≥ 1.4 to ≤11.5 µg/L) at Screening.

Exclusion Criteria:

1. Female who is breastfeeding or is pregnant according to the pregnancy test at Screening or on Day -1, or is planning to become pregnant any time during the study and for 8 months after study drug administration.

2. Body temperature ≥ 38°C/100.4 F or symptomatic viral or bacterial infection within 2 weeks prior to Screening, or active or acute infection requiring systemic antibiotic treatment (oral or IV) within 4 weeks prior to Screening.

3. History of clinically significant anaphylaxis, food allergies, asthma, or allergies (chronic or seasonal) requiring medication, as determined by an Investigator.

4. Known or suspected intolerance to SAB01 or any related products (including excipients of the formulations).

5. History of clinically significant diseases within 5 years prior to study drug administration.

6. Clinically significant illness within 4 weeks of study drug administration.

7. Previous or concurrent malignancy with the following exceptions:

   1. Adequately treated basal cell or squamous cell carcinoma,
   2. In situ carcinoma of the uterine cervix or breast, treated curatively and without evidence of recurrence for at least 3 years prior to Screening.

8. History of alcohol or drug abuse (within 1 year of Screening).

9. History of benign neutropenia and/or an absolute neutrophil count of < 2.0 × 109/L or 2.0 × 103/µL at Screening or on Day -1.

10. Use of any prescription drugs (with the exception of hormonal contraceptives or hormonal replacement therapy), over-the-counter (OTC) medications, vitamins, herbal medicines (including St. John's wort) or cannabis within 7 days or 5 half-lives (whichever is longer) prior to study drug administration, that in the opinion of an Investigator would put into question the status of the participant as healthy. Acetaminophen is permitted provided the total daily dose does not exceed 2 g per day.

11. Consumption of > 21 alcohol units per week (where 1 unit = 284 mL of beer, 25 mL of 40% spirit, or a 125 mL glass of wine).

12. Currently enrolled in another investigational drug or device study, or less than 30 days or 5 half-lives of the prior investigational agent (whichever is longer) have passed since completion of another investigational drug or device study; or plans to enroll in another investigational drug or device study during participation in this study.