1128 A global survey of P. vivax genome variation in samples from two GSK phase 3 clinical trials of tafenoquine in Pv relapse/reinfection (trial names DETECTIVE and GATHER)


Locations: Brazil (BR), Ethiopia (ET), Cambodia (KH), Philippines (PH), Thailand (TH), Peru (PE), Vietnam (VN)

Partner study description

As a service to the P. vivax genomics scientific community, GSK made DNA from the DETECTIVE and GATHER trials available for whole genome sequencing and analysis. The whole genome sequence data was not used in any way as part of any clinical trials.

DETECTIVE was a prospective, double-blind, randomised, placebo-controlled, fully powered superiority trial comparing the safety and efficacy of tafenoquine 300 mg single dose to placebo when used in conjunction with chloroquine. Patients with uncomplicated P. vivax malaria and G6PD activity >70% were recruited from 8 sites in six countries (Brazil, Peru, Ethiopia, Thailand, Cambodia & the Philippines). A primaquine arm was included as a benchmark positive control (15 mg daily for 14 days). The primary endpoint was based upon the proportion of patients who were free from recurrence at 6 months (defined as P. vivax clearance without recurrent parasitaemia) with safety as a key secondary endpoint. This study was considered the pivotal trial supporting registration of tafenoquine with the US FDA. The study is described at https://www.nejm.org/doi/full/10.1056/NEJMoa1710775.

GATHER was a prospective, double-blind, randomized, controlled trial comparing the safety profile of tafenoquine 300mg single dose against primaquine 15mg daily for 14 days in patients presenting with uncomplicated P. vivax malaria and G6PD activity >40%. Participants were recruited from seven in sites in Peru, Brazil, Colombia, Vietnam, and Thailand. The primary endpoint of the GATHER study was haemoglobin decrease (>3.0 g per deciliter or ≥30% from baseline or to a level of <6.0 g per deciliter). A key secondary endpoint was freedom from recurrence of P. vivax parasitemia at 6 months. Safety data from the GATHER study was used to support registration of tafenoquine with the US FDA. The study is described at https://www.nejm.org/doi/full/10.1056/NEJMoa1802537.