The purpose of the study is to understand the gastrointestinal transit time and disintegration behavior of the formulations in vivo in normal healthy volunteers when ALLN-346 formulations are given with light meal or in fasted or other fed states.

This study includes two parts. Part One will evaluate two ALLN-346 formulations, a fast release and a slower sustained release. Subjects will receive a single tablet of each formulation and a capsule of each formulation at separate assessment visits. Subjects will attend a maximum of 4 assessment visits. The primary purpose of this part of the study is to understand the gastrointestinal transit time and disintegration behaviour of the formulations in vivo in normal healthy volunteers when ALLN-346 formulations are given with light meal.

Part Two will involve a second cohort of subjects and will comprise further scintigraphic studies on one or both formulation(s) from Part One in fasted and/or fed states. Subjects will attend a maximum of 4 assessment visits, the number of treatment arms will be decided following completion of Part One.

Inclusion Criteria:

• BMI between 18 and 30 kg/m², inclusive.
• Body weight ≥50 kg
• Voluntary written informed consent
• Good general health with no clinically significant and/or relevant abnormalities of medical history or prior to dosing evaluations, including physical examination, vital signs and ECG and screening clinical laboratory results

Exclusion Criteria:

• Current or recurrent disease that could affect the study conduct or laboratory assessments
• History of current or relevant previous non-self-limiting gastrointestinal disorders
• Currently suffering from disease known to impact gastric emptying, e.g., migraine, Type 1 or Type 2 diabetes mellitus
• Untreated hypertension or has hypertension under treatment.
• Diagnosis of an immunosuppressive illness or a condition requiring chronic immunosuppression.
• As a result of a physical examination or screening investigations, and available prior to dosing evaluations, the PMI or medically qualified designee/physician responsible considers the volunteer unfit for the study
• Any contradictions to the gamma scintigraphy procedure
• Measured body temperature >38°C at screening visit (COVID-19 risk reduction procedure)