The purpose of this study is to assess the preliminary efficacy of single SC administration of MBX 1416 at different dose levels in patients with PBH

This is a Phase 2a, open-label, exploratory study to evaluate preliminary efficacy of SC MBX 1416 in patients with PBH. Approximately 20 patients aged 18 to 75 (inclusive) years with history of hypoglycemia following Roux-en-Y or sleeve gastrectomy will be included in the study. Participants will undergo 3 mixed-meal tolerance tests, one at baseline and again 48 hours after each MBX 1416 administration, to evaluate the effect of MBX 1416 on increasing post-prandial glucose nadir. MBX 1416 effect in reducing post-prandial insulin and C-peptide peaks will also be evaluated

Inclusion Criteria:

1. Participant must be ≥18 to ≤75 years of age at the time of signing the informed consent.
2. Participants must have undergone RYGB or SG surgery at least 12 months prior to study entry.
3. Participants should have a documented history of PBH, defined as Whipple's triad (symptomatic hypoglycemia, capillary glucose ≤54 mg/dL, with symptom resolution by carbohydrate administration) and a minimum of 1 symptomatic hypoglycemic episode per month by patient report.
4. Participants who are either treatment naïve or who are no longer using (i.e., have discontinued as part of their usual medical care) agents known to interfere with glucose metabolism at the time of screening.
5. Participants must have a body mass index (BMI) <45 kg/m2 at screening.
6. Must have signed informed consent.

Exclusion Criteria:

1. History of, or currently active, significant illness or medical disorders that in the opinion of the investigator may preclude participants from participating in the study.
2. Currently on-going type II diabetes mellitus.
3. History of hypoglycemia prior to bariatric surgery.
4. History of insulinoma or other endogenous hyperinsulinemia illness (e.g., congenital hyperinsulinism).