Healthy VolunteersPhase 2NCT03320174
Long-Term Safety Study of Tafenoquine
A Phase 2 study testing Tafenoquine in people with Healthy Volunteers, run by 60 Degrees Pharmaceuticals LLC at 3 sites in 2 countries.
Trial 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… Read more about this study
- Who is it for?
- Ages 18 to 55 yearsHealthy volunteers can take part
- Conditions the study is for
- Healthy Volunteers
- What is being tested?
- Tafenoquine
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 600 participants
- Where
- 3 sitesin 2 countries
- Study dates
- 5 Oct 2017to 13 Jul 2021
- Phase
- Phase 2
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 55 years
- All sexes
- Healthy volunteers accepted
- Adult
Main Inclusion Criteria:
- 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.
Main Exclusion Criteria:
- 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
Trial locations and contacts
3 sites in 2 countries.
3 sites in 2 countries
United States2 sites
Retina Consultants of Southern Colorado
Colorado Springs, Colorado, 80909
Valley Retina Institute
McAllen, Texas, 78503
About this study
Official title: Single Site, Randomized, Double Blind, Placebo-Controlled Study to Assess the Long-Term Safety of Tafenoquine
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
- Being tested
- Tafenoquine, Placebo
- Keywords
- tafenoquine, australia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
TafenoquineDrug
Tafenoquine 200mg
PlaceboOther
Placebo
| Study group | Role | What they receive |
|---|---|---|
| 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 Receives: 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 Receives: Other: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
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.
Measured: After 12 months of exposure to study drug
Secondary outcomes (11)
Number of Participants With Mean Change From Baseline in Key SD OCT Parameters
Mean change from baseline in key SD OCT parameters including central subfield thickness, total macular volume, and parafoveal (inner ring of Early Treatment Diabetic Retinopathy Study, and retinal thickness.
Clinically significant change from baseline for central subfield thickness [change from baseline of at least 40 µm (15% change)].
Clinically significant change from baseline for total macular volume [change of > 10% (0.86 mm3) from baseline].
Clinically significant change from baseline for parafoveal (inner ring) retinal thickness [change from baseline of at least 10 µm].
Clinically significant change from baseline for qFAF (change in mid-ring qFAF unit from baseline of at least 12% in both eyes at the same visit).
Measured: After 12 months of exposure to study drug
Number of Participants With Ellipsoid or Interdigitating Zone Disruption
Any ellipsoid or interdigitating zone disruption within the ETDRS grid
Measured: After 12 months of exposure to study drug
Number of Participants With Mean Change From Baseline in Best Corrected Visual Acuity
Mean change from baseline in BCVA score, the number of participants that have any clinically significant change in ETDRS BCVA (defined as ≥15 letter change [≥ 3 lines] of change in ETDRS BCVA at 4 meters).
Measured: After 12 months of exposure to study drug
Number of Participants With Corneal Deposits From Slit Lamp Examination of the Corneal Epithelium
Slit lamp examination was use to detect and grade corneal deposits (also known as vortex keratopathy or cornea verticillata) and retinal abnormalities arising from drug-induced phospholipidosis.
Measured: After 12 months of exposure to study drug
Number of Participants With New Abnormalities Compared With Baseline Observed With Color Retinal Digital Photography
Corneal deposits as determined by digital corneal photographs that are indicative of cornea verticillata also known as vortex keratopathy
Measured: After 12 months of exposure to study drug
Number of Participants With New Abnormalities Compared With Baseline Observed With Microperimetry
Microperimetry can be a useful tool for objective evaluation of macular function and progression of disease. Macular disease causes impairment of central vision, metamorphopsia, macropsia, micropsia and color vision defect. Microperimetry measures fixation stability which is associated with visual acuity.
Measured: After 12 months of exposure to study drug
Number of Participants With Any Clinically Significant Change in ETDRS BCVA (Defined as >15 Letter Change [≥ 3 Lines] of Change in ETDRS BCVA at 4 Meters)
Visual acuity was measured in a consistent way in order to detect any changes in vision as described in the Ophthalmic Reference Manual using a set of Early Treatment Diabetic Retinopathy Study (ETDRS) charts and a retro-illuminated box providing standardized illumination. Subjects are seated 4 meters from the letter chart and asked to read the letters. Letters read correctly count towards the total score. In addition, there are 5 letters in each of the 14 lines. The lines are of equal difficulty and follow a logarithmic progression of diminishing letter size related to the minimum angle of resolution. The endpoints include mean change from baseline in BCVA score, the proportion of participants that have any clinically significant change in ETDRS BCVA (defined as ≥15 letter change [≥ 3 lines] of change in ETDRS BCVA at 4 meters).
Measured: After 12 months of exposure to study drug
Proportion of Participants Who Develop a Color Deficiency Using the Farnsworth-Munsell 100 (FM-100) Hue Test
Color deficiency was assessed using the Farnsworth-Munsell 100 (FM-100) hue test
Measured: After 12 months of exposure to study drug
Number of Participants Who Develop a Loss of 0.12 or Greater Logarithm of Contrast Sensitivity (logCS) on the Mars Letter Contrast Sensitivity Test
The Mars letter contrast sensitivity test is a set of charts for testing peak visual contrast sensitivity. Subjects are asked to read to letters from left to right across the chart. The logarithm of contrast sensitivity (logCS) score is given by the log contrast sensitivity value at the lowest contrast letter just prior to two incorrectly identified letters, minus a scoring correction.
Measured: After 12 months of exposure to study drug
Number of Participants Who Develop a Psychiatric Disorder in Accordance With DSM-5 as Assessed With the Mini International Neuropsychiatric Interview (M.I.N.I.) 7.0.2 Assessment Questionnaire
Psychiatric disorders were reported as adverse events
Measured: After 12 months of exposure to study drug
Number of Participants With an AE of Dizziness or Vertigo and Severity as Assessed by the Dizziness Handicap Inventory
The period of observation for collection of AEs extended from the time of dosing (Day 1, Week 1 [Visit 2]) through the Week 64 follow-up visit. Proportion of participants with an AE of dizziness or vertigo are reported here.
Measured: After 12 months of exposure to study drug
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 Oct 2017
- Study start5 Oct 2017
- Primary completion13 Jul 2021
- Study completion13 Jul 2021
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Healthy VolunteersStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 600 participants (actual)
Sponsor and investigators
- Lead sponsor
- 60 Degrees Pharmaceuticals LLC
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03320174
- Sponsor's protocol ID
- 60PH04
- Status last verified
- Sep 2025
- First submitted
- 18 Oct 2017
- Last updated
- 17 Apr 2026
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
Publications
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.
PubMed 34801714
Study at a glance
From the registry record, last updated by the sponsor on 17 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Single Site, Randomized, Double Blind, Placebo-Controlled Study to Assess the Long-Term Safety of Tafenoquine
- ClinicalTrials.gov ID
- NCT03320174
- Acronym / sponsor ID
- 60PH04
- Conditions
- Healthy Volunteers
- Keywords
- tafenoquine, australia
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 600 participants (actual)
- Lead sponsor
- 60 Degrees Pharmaceuticals LLCIndustry (pharma, biotech, devices)
- Study start
- 5 Oct 2017 (actual)
- Primary completion
- 13 Jul 2021 (actual)
- Study completion
- 13 Jul 2021 (actual)
- First posted
- 25 Oct 2017 (actual)
- Results
- Posted 17 Apr 2026
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Tafenoquine 200 mg (2 x 100 mg tablets) | Active comparator | Drug: TafenoquineTafenoquine 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 |
| Placebo | Placebo comparator | Other: PlaceboPlacebo daily for three consecutive days, followed by study treatment (tafenoquine 200 mg or placebo) once per week for 51 weeks |
Who may qualify
- Ages
- 18 to 55 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| TafenoquineTafenoquine 200mg | Drug | Tafenoquine 200 mg (2 x 100 mg tablets) |
| PlaceboPlacebo | Other | Placebo |
Primary outcome
Serious Ophthalmic Safety Event
Time frame: After 12 months of exposure to study drug
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.
11 secondary outcomes
Number of Participants With Mean Change From Baseline in Key SD OCT Parameters
Time frame: After 12 months of exposure to study drug
Number of Participants With Ellipsoid or Interdigitating Zone Disruption
Time frame: After 12 months of exposure to study drug
Number of Participants With Mean Change From Baseline in Best Corrected Visual Acuity
Time frame: After 12 months of exposure to study drug
Number of Participants With Corneal Deposits From Slit Lamp Examination of the Corneal Epithelium
Time frame: After 12 months of exposure to study drug
Number of Participants With New Abnormalities Compared With Baseline Observed With Color Retinal Digital Photography
Time frame: After 12 months of exposure to study drug
Number of Participants With New Abnormalities Compared With Baseline Observed With Microperimetry
Time frame: After 12 months of exposure to study drug
Number of Participants With Any Clinically Significant Change in ETDRS BCVA (Defined as >15 Letter Change [≥ 3 Lines] of Change in ETDRS BCVA at 4 Meters)
Time frame: After 12 months of exposure to study drug
Proportion of Participants Who Develop a Color Deficiency Using the Farnsworth-Munsell 100 (FM-100) Hue Test
Time frame: After 12 months of exposure to study drug
Number of Participants Who Develop a Loss of 0.12 or Greater Logarithm of Contrast Sensitivity (logCS) on the Mars Letter Contrast Sensitivity Test
Time frame: After 12 months of exposure to study drug
Number of Participants Who Develop a Psychiatric Disorder in Accordance With DSM-5 as Assessed With the Mini International Neuropsychiatric Interview (M.I.N.I.) 7.0.2 Assessment Questionnaire
Time frame: After 12 months of exposure to study drug
Number of Participants With an AE of Dizziness or Vertigo and Severity as Assessed by the Dizziness Handicap Inventory
Time frame: After 12 months of exposure to study drug
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 17 Apr 2026.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Derived from this study: PubMed 34801714Novitt-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.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
3 sites in 2 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing Tafenoquine in people with Healthy Volunteers, run by 60 Degrees Pharmaceuticals LLC at 3 sites in 2 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 17 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 3 sites in United States, Australia. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
Yes. Results are posted in the registry (first posted 17 Apr 2026). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Serious Ophthalmic Safety Event (time frame: After 12 months of exposure to study drug). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT03320174, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 17 Apr 2026.