Safety, Tolerability, and Pharmacokinetics (PK) of Single and Multiple Ascending Oral Doses of XEN1101.

Parts 1 & 2: Number of Participants with Adverse Events (AEs)

To assess AEs as a criteria of safety and tolerability

Time frame: From screening (28 days prior to Day 1) through to 30 days post-final dose

Parts 1 & 2: Resting electrocardiogram (ECG)

To assess ECG as a criteria of safety and tolerability

Time frame: At screening (28 days prior to Day 1) through to 7 days post-final dose

Parts 1 & 2: Vital signs

To assess vital signs as a criteria of safety and tolerability

Time frame: At screening (28 days prior to Day 1) through to 7 days post-final dose

Part 3a: Maximum Observed Plasma Concentration (Cmax) of XEN1101

To characterize the PK profile of XEN1101 and M11 (a metabolite of XEN1101) in plasma of single ascending, oral doses of XPF-010

Time frame: At screening (27 days prior to Day -1) through to 31 days post dose

Part 3a: Area under the plasma concentration-time curve (AUC) of XEN1101

To characterize the PK profile of XEN1101 and M11 (a metabolite of XEN1101) in plasma of single ascending, oral doses of XPF-010

Time frame: At screening (27 days prior to Day -1) through to 31 days post dose

Part 3a: Frequency and severity of treatment-emergent adverse events (TEAEs), treatment-emergent serious adverse events (SAEs), and TEAEs leading to treatment discontinuations

To evaluate the safety and tolerability of XEN1101 (XPF-010)

Time frame: At screening (27 days prior to Day -1) through to 31 days post dose

Part 3b: Maximum Observed Plasma Concentration (Cmax) of XEN1101

To assess the Food Effect on PK (Cmax) and the relative bioavailability/comparability (Cmax) of XEN1101 following single oral doses of XPF-010 (fed), XPF-008 (fed) and XPF-010 (fasted)

Time frame: At screening (27 days prior to Day -1) through to 31 days post dose

Part 3b: Area under the plasma concentration-time curve (AUC) of XEN1101

To assess the Food Effect on PK (AUC0-240h) and the relative bioavailability/comparability (AUC0-240h) of XEN1101 following single oral doses of XPF-010 (fed), XPF-008 (fed) and XPF-010 (fasted)

Time frame: At screening (27 days prior to Day -1) through to 31 days post dose

Part 3b: Frequency and severity of TEAEs, treatment-emergent SAEs, and TEAEs leading to treatment discontinuations

To evaluate the safety and tolerability of XEN1101

Time frame: At screening (27 days prior to Day -1) through to 31 days post dose

Part 4: Maximum Observed Plasma Concentration (Cmax) of XEN1101

To characterize the PK profile of XEN1101 and M11 (metabolite of XEN1101) in plasma of multiple daily oral doses of XPF-010

Time frame: At screening (27 days prior to Day -1) through to 51 days post dose

Part 4: Area under the plasma concentration-time curve (AUC) of XEN1101

To characterize the PK profile of XEN1101 and M11 (metabolite of XEN1101) in plasma of multiple daily oral doses of XPF-010

Time frame: At screening (27 days prior to Day -1) through to 51 days post dose

Part 4: Frequency and severity of TEAEs, treatment-emergent SAEs, and TEAEs leading to treatment discontinuations

To evaluate the safety and tolerability of XEN1101 (XPF-010)

Time frame: At screening (27 days prior to Day -1) through to 51 days post dose

Part 5: Maximum Observed Plasma Concentration (Cmax) of XEN1101

To assess the PK of XEN1101 (XPF-010) in the presence and absence of itraconazole

Time frame: Day 10 and Day 11

Part 5: Area under the plasma concentration-time curve (AUC) of XEN1101

To assess the PK of XEN1101 (XPF-010) in the presence and absence of itraconazole

Time frame: Day 10 and Day 11

Part 5: Frequency and severity of TEAEs, treatment-emergent SAEs, and TEAEs leading to treatment discontinuations

To evaluate the safety and tolerability of XEN1101 (XPF-010)

Time frame: At screening (27 days prior to Day -1) through to 51 days post dose