Safety and Tolerability of SYNB1020-CP-001

This Phase 1, dose-escalating, randomized, double-blinded study will evaluate SYNB1020 in placebo-controlled cohorts within the following 2 study parts:

Part 1: A single-ascending dose (SAD) study conducted in an inpatient setting over 6 days in healthy volunteer male and female subjects evaluated in up to 7 dose cohorts to identify the maximum tolerated dose (MTD) within the single dose range studied; and Part 2: A multiple-ascending dose (MAD) study conducted in an inpatient setting over 22 days in healthy volunteer male and female subjects evaluated in up to 4 dose cohorts that were proven tolerable in the SAD part of the study to identify the MTD of SYNB1020 within the multiple-dose range studied. Up to 48 subjects may be enrolled in this part of the study.

Subjects will be screened for eligibility within 30 days prior to enrollment, with evaluations of exercise habits, gastrointestinal (GI) signs and symptoms, fecal patterns (frequency, consistency), recent or current antibiotic exposure, and laboratory measurements. Eligible patients will be admitted to an inpatient facility for investigational product (IP) administration, safety monitoring, and collection of blood, urine, and fecal samples for pharmacokinetic and pharmacodynamic evaluations.

• Placebo (Drug): Placebo
• SYNB1020 (Drug): Investigational Product

Primary outcomes

• Incidence of Treatment-Emergent Adverse Events, Laboratory Assessments and ECGs to measure Safety and Tolerability of SYNB1020 [3 months from study entry]: Will be measured by assessing nature and frequency of AEs, Laboratory Assessments, and ECGs

Secondary outcomes

• GI tolerability measured using the Gastrointestinal Symptom Rating Scale (GSRS) [1 month of study entry]: Will be measured using the Gastrointestinal Symptom Rating Scale (GSRS)
• SYNB1020 kinetics measured by qPCR fecal assays [3 months from study entry]: Will be measured by qPCR fecal assays

Sex: All, ages: 18 Years to 64 Years, accepts healthy volunteers

Key Inclusion Criteria:

* Age 18 to 64 years
* Healthy volunteer Males and Females; Females must be of non childbearing potential
* Able and willing to complete informed consent process
* Available for and agree to all study procedures
* Screening Labs within normal range

Key Exclusion Criteria:

* Acute or chronic medical, surgical, psychiatric, social or laboratory abnormality
* Body mass index < 18.5 or ≥ 30 kg/m2
* Intolerance of or allergic reaction to E. coli Nissle or any of the ingredients in SYNB1020 or placebo formulations; allergies to common foods (e.g., eggs, milk, soy, nuts).
* Prior participation in a study with SYNB1020
* Evidence or history of clinical signification hematological, renal, endocrine, pulmonary, GI cardiovascular, hepatic, psychiatric, neurologic or allergic disease
* Personal or family history of UCD