Long-Term Safety Study of Tafenoquine

NCT03320174 | Completed Phase 2 Results DMC FDA Drug

• 1 other identifier: 60PH04
• Study Type: interventional
• Target: 600
• Locations: 2 countries
• Sites: 3

Brief Summary

This randomized, double-blind, placebo controlled study will involve 600 healthy (Glucose-6-Phosphate Dehydrogenase \[G6PD\] normal) volunteers. Participants who meet the eligibility criteria will be randomized (ratio 1:1) to receive a loading dose of either tafenoquine 200 mg (2 x 100 mg tablets) or placebo daily for three consecutive days, followed by study treatment (tafenoquine 200 mg or placebo) once per week for 51 weeks, with safety follow-up visits at Weeks 4, 12, 24, and 52. All participants will return to the clinic at Week 64 for an end of study visit. If the participant has an ongoing AE at the Week 64 visit will continue to be assessed for up to 3 more times at approximately 12-week intervals or until resolution or stabilization of the AE whichever is earlier.

Conditions

Healthy Volunteers

Keywords

tafenoquine; australia

Outcome Measures

Primary Outcomes (1)

• Serious Ophthalmic Safety Event

  Number of Participants with One or More protocol-defined serious ophthalmic safety event (SOSE) assessed by retinal changes from baseline using SD-OCT and qFAF. SOSE is assessed by significant retinal changes from baseline using SD-OCT and qFAF.

  After 12 months of exposure to study drug

Secondary Outcomes (11)

• Number of Participants With Mean Change From Baseline in Key SD OCT Parameters

  After 12 months of exposure to study drug

• Number of Participants With Ellipsoid or Interdigitating Zone Disruption

  After 12 months of exposure to study drug

• Number of Participants With Mean Change From Baseline in Best Corrected Visual Acuity

  After 12 months of exposure to study drug

• Number of Participants With Corneal Deposits From Slit Lamp Examination of the Corneal Epithelium

  After 12 months of exposure to study drug

• Number of Participants With New Abnormalities Compared With Baseline Observed With Color Retinal Digital Photography

  After 12 months of exposure to study drug

Study Arms (2)

Tafenoquine 200 mg (2 x 100 mg tablets)

ACTIVE COMPARATOR

Tafenoquine 200 mg (2 x 100 mg tablets) daily for three consecutive days, followed by study treatment (tafenoquine 200 mg or placebo) once per week for 51 weeks

Drug: Tafenoquine

Placebo

PLACEBO COMPARATOR

Placebo daily for three consecutive days, followed by study treatment (tafenoquine 200 mg or placebo) once per week for 51 weeks

Other: Placebo

Interventions

Tafenoquine DRUG

Tafenoquine 200mg

Tafenoquine 200 mg (2 x 100 mg tablets)

Placebo OTHER

Placebo

Placebo

Eligibility Criteria

• Age: 18 Years - 55 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Completion of the written informed consent process (signed).
• Male or female age 18 to 55 years inclusive, in good health as assessed by the Investigator.
• Normal G6PD enzyme activity levels as defined by the parameters of the specific G6PD test employed at the local laboratory.
• Negative HBsAg and HCV, HIV-1, HIV-2 antibody screen at the screening visit.
• Negative serum pregnancy test.
• Use acceptable method of birth control.
• Hematology, biochemistry and urinalysis results at screening that are within the local laboratory reference range or, if outside the range, not clinically significant as judged by the Investigator in accordance with approved clinically acceptable laboratory ranges, documented prior to study start.
• Willing and able to comply with all scheduled visits, treatment plan, laboratory tests, and other study procedures.

You may not qualify if:

• History of allergy or intolerance to tafenoquine, primaquine or any excipients.
• History of thalassemia or current or past history of methemoglobinemia or methemoglobin \>2% at screening.
• History of eye disease or surgery
• Having previously received hydroxychloroquine for skin conditions or rheumatological diseases, chloroquine for malaria, tamoxifen, amiodarone or other drugs that may affect the optic nerve/retina/cornea within 30 days or 5 half-lives (whichever is longer) of study start. There are no travel restrictions, but the choice of concurrent anti-malarial must be atovaquone-proguanil if the participant chooses to take a registered antimalarial drug while travelling.
• Any current diagnosis of Axis I psychiatric disorders

Sponsors & Collaborators

• 60 Degrees Pharmaceuticals LLC: lead

Study Sites (3)

Retina Consultants of Southern Colorado

Colorado Springs, Colorado, 80909, United States

Location

Valley Retina Institute

McAllen, Texas, 78503, United States

Location

Linear Clinical Research

Nedlands, Western Australia, 6009, Australia

Location

Related Publications (1)

• Novitt-Moreno A, Martidis A, Gonzalez V, Ransom J, Scott CB, Dow G, Reid M, Smith B, Zottig VE, Read LT, Garver Baldwin LS, Chen FK. Long-term safety of the tafenoquine antimalarial chemoprophylaxis regimen: A 12-month, randomized, double-blind, placebo-controlled trial. Travel Med Infect Dis. 2022 Jan-Feb;45:102211. doi: 10.1016/j.tmaid.2021.102211. Epub 2021 Nov 18.

  PMID: 34801714 DERIVED

MeSH Terms

Interventions

tafenoquine

Results Point of Contact

• Title: Katrina Riggs
• Organization: Fast-Track Drugs & Biologics, LLC

kriggs@fastttrackresearch.com

3017622609

Publication Agreements

• PI is Sponsor Employee: No
• Restrictive Agreement: Yes

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: Identically matched placebo control.
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: October 18, 2017
• First Posted: October 25, 2017
• Study Start: October 5, 2017
• Primary Completion: July 13, 2021
• Study Completion: July 13, 2021
• Last Updated: April 17, 2026
• Results First Posted: April 17, 2026

Record last verified: 2025-09

Locations

US (2); AU (1)