Conditions: Migraine
Allocation: NON_RANDOMIZED | Intervention model: PARALLEL
Enrollment: 10
Healthy volunteers: yes

Brief summary:
The purpose of this study is to determine the receptor occupancy (RO) associated with telcagepant (MK-0974) administration based on displacement of \[11C\]MK-4232 from the CGRP receptors in the brain using PET. The study enrolled healthy participants (Part I) and migraine patients (Part III). Due to a protocol amendment, study Part II was not conducted.

Detailed description:
For the 1120 mg (i.e., maximal) telcagepant dose, \[11C\]MK-4232 was administered and PET scan was started \~3 hours post telcagepant to coincide with the Tmax of the 1120 mg dose. For the 140 mg (i.e., therapeutic) telcagepant dose, \[11C\]MK-4232 was administered and PET scan was started \~2 hours post telcagepant to correspond with the timing of clinical efficacy measurements of telcagepant for migraine treatment in Phase III studies.

Arms:
arm 1: Baseline PET imaging of the brain using \[11C\]MK-4232 tracer (\~300 megabecquerel \[MBq\]) was performed in healthy participants; this PET data served as the baseline for both Period 1 and 2 of Part I. Subsequently in study Part I, Period 1 the healthy participants received a single 1120 mg dose of telcagepant followed by PET imaging of brain with \[11C\]MK-4232 tracer (\~300 MBq) beginning \~3 hours post telcagepant dose. In Part I, Period 2 the healthy participants received a single 140 mg dose of telcagepant followed by PET imaging of brain with \[11C\]MK-4232 tracer (\~300 MBq) beginning \~2 hours post telcagepant dose. Interval between Part I Period 1 and 2 was to be at least 1 week. arm 2: In study Part III, Period 1 baseline PET imaging of the brain using \[11C\]MK-4232 tracer (\~300 MBq) was performed in participants with migraine during a migraine attack (ictal phase). Later in Part III, Period 1 the participants with an ongoing migraine attack (ictal phase) received a single 140 mg dose of telcagepant followed by PET imaging of brain with \[11C\]MK-4232 tracer (\~300 MBq) beginning \~2 hours post telcagepant dose. In Part III, Period 2 baseline PET imaging of the brain using \[11C\]MK-4232 tracer (\~300 MBq) was performed in participants with migraine, however, without a migraine attack ongoing (interictal phase). Later in Part III, Period 2 participants with migraine without a migraine attack ongoing (interictal phase) received a single 140 mg dose of telcagepant followed by PET imaging of brain with \[11C\]MK-4232 tracer (\~300 MBq) beginning \~2 hours post telcagepant dose. Interval between Part III Period 1 and 2 was to be at least 1 week.

Interventions: intervention 1: telcagepant intervention 2: [11C]MK-4232
Intervention descriptions: intervention 1: Single oral doses of telcagepant 1120 mg (Part I - Period 1) and 140 mg (Part I - Period 2; Part III - Period 1 and 2) intervention 2: Single intravenous doses of \~300 MBq \[11C\]MK-4232 administered as a 5 minute infusion (Part I - Baseline, Period 1 and 2; Part III - Period 1 Baseline and Period 1, and Period 2 Baseline and Period 2)

Protocol document: