This is a single-centre, randomised, double-blind, placebo-controlled, parallel group dose escalation, safety, tolerability and pharmacokinetic (PK) study of single escalating and multiple doses of GWP42006 in healthy volunteers. The study consists of 5 single dosing occasions, and a five day repeated dose period.~Part 1 Single Dosing:~Four parallel groups of 11 subjects will participate in the oral single dosing, dose escalation study phase. In each group, subjects will be randomly assigned so that eight subjects receive active and three subjects receive placebo. It is planned for Groups 1 and 2, that a staggered 'sentinel' dose design will be used, with two sub-groups:~The first will comprise of one placebo and one active subject.~In the second, seven subjects will receive active and two will receive placebo after a review of the 24 h post-dose safety data of the first group.~Sentinel subject dosing will be performed in higher-dose groups if there is no measurable plasma GWP42006 in Group 1 or 2.~One group within the single dosing part (Group 3/dose level 3) will then receive an intravenous administration of 5 mg GWP42006 to allow assessment of bioavailability. There will be a minimum of seven days between doses.~Up to three further groups may be added for further evaluations, e.g. to assess additional dose levels or food effect. The need for additional groups will be based on a review of the safety, tolerability and PK data by the safety advisory committee.~Dose Escalation:~The planned dose levels are 25 mg (Group 1/dose level 1), 75 mg (Group 2/dose level 2), 200 mg (Group 3/dose level 3) and 400 mg (Group 4/dose level 4), with a maximum dose of 800 mg. Administration of each successive dose will be dependent on safety, tolerability and PK data of previous doses.~Part 2 Multiple Dosing:~The doses and dose regimens assessed in Part 2 will be selected based upon the safety, and PK data from Part 1 of the study.~It is planned that one group of 11 subjects will participate in the multiple dose phase, and subjects will be randomly assigned so that eight subjects receive active and three receive matching placebo. Each subject will receive the selected dose of GWP42006 or placebo once, twice or three times daily for a total of five days, with the final dose administered on the morning of Day 5.~Up to two further groups may be added for further evaluations, e.g. to assess a different dose level or a different dosing frequency. As for single dosing, the decision to include further groups will be taken based on safety, tolerability and PK data. All further groups would be added on blinded information.
The primary objective of this study is to evaluate the safety and tolerability of single ascending (increasing) and multiple doses of GWP42006 compared with placebo.