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Long-Term Safety Study of Tafenoquine

Single Site, Randomized, Double Blind, Placebo-Controlled Study to Assess the Long-Term Safety of Tafenoquine

Status
Completed
Phases
Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT03320174
Enrollment
600
Registered
2017-10-25
Start date
2017-10-05
Completion date
2021-07-13
Last updated
2026-04-17

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Healthy Volunteers

Keywords

tafenoquine, australia

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.

Interventions

Tafenoquine 200mg

OTHERPlacebo

Placebo

Sponsors

60 Degrees Pharmaceuticals LLC
Lead SponsorINDUSTRY

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)

Masking description

Identically matched placebo control.

Eligibility

Sex/Gender
ALL
Age
18 Years to 55 Years
Healthy volunteers
Yes

Inclusion criteria

Main Inclusion Criteria: 1. Completion of the written informed consent process (signed). 2. Male or female age 18 to 55 years inclusive, in good health as assessed by the Investigator. 3. Normal G6PD enzyme activity levels as defined by the parameters of the specific G6PD test employed at the local laboratory. 4. Negative HBsAg and HCV, HIV-1, HIV-2 antibody screen at the screening visit. 5. Negative serum pregnancy test. 6. Use acceptable method of birth control. 7. 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. 8. Willing and able to comply with all scheduled visits, treatment plan, laboratory tests, and other study procedures. Main

Exclusion criteria

1. History of allergy or intolerance to tafenoquine, primaquine or any excipients. 2. History of thalassemia or current or past history of methemoglobinemia or methemoglobin \>2% at screening. 3. History of eye disease or surgery 4. 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. 5. Any current diagnosis of Axis I psychiatric disorders

Design outcomes

Primary

MeasureTime frameDescription
Serious Ophthalmic Safety EventAfter 12 months of exposure to study drugNumber 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.

Secondary

MeasureTime frameDescription
Number of Participants With Mean Change From Baseline in Key SD OCT ParametersAfter 12 months of exposure to study drugMean 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).
Number of Participants With Ellipsoid or Interdigitating Zone DisruptionAfter 12 months of exposure to study drugAny ellipsoid or interdigitating zone disruption within the ETDRS grid
Number of Participants With Mean Change From Baseline in Best Corrected Visual AcuityAfter 12 months of exposure to study drugMean 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).
Number of Participants With Corneal Deposits From Slit Lamp Examination of the Corneal EpitheliumAfter 12 months of exposure to study drugSlit 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.
Number of Participants With New Abnormalities Compared With Baseline Observed With Color Retinal Digital PhotographyAfter 12 months of exposure to study drugCorneal deposits as determined by digital corneal photographs that are indicative of cornea verticillata also known as vortex keratopathy
Number of Participants With New Abnormalities Compared With Baseline Observed With MicroperimetryAfter 12 months of exposure to study drugMicroperimetry 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.
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)After 12 months of exposure to study drugVisual 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).
Proportion of Participants Who Develop a Color Deficiency Using the Farnsworth-Munsell 100 (FM-100) Hue TestAfter 12 months of exposure to study drugColor deficiency was assessed using the Farnsworth-Munsell 100 (FM-100) hue test
Number of Participants Who Develop a Loss of 0.12 or Greater Logarithm of Contrast Sensitivity (logCS) on the Mars Letter Contrast Sensitivity TestAfter 12 months of exposure to study drugThe 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.
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 QuestionnaireAfter 12 months of exposure to study drugPsychiatric disorders were reported as adverse events
Number of Participants With an AE of Dizziness or Vertigo and Severity as Assessed by the Dizziness Handicap InventoryAfter 12 months of exposure to study drugThe 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.

Countries

Australia, United States

Baseline characteristics

Characteristic
Age, Categorical
<=18 years
0 Participants
Age, Categorical
>=65 years
0 Participants
Age, Categorical
Between 18 and 65 years
600 Participants
Age, Continuous31.3 years
Best Corrected Visual Accuity60.2 letters
STANDARD_DEVIATION 3.55
Central Subfield Thickness268.82 um
STANDARD_DEVIATION 19.3
Parafoveal (inner ring) retinal thickness343.40 um
STANDARD_DEVIATION 14.35
Parafoveal (outer ring) retinal thickness301.87 um
STANDARD_DEVIATION 12.75
Race (NIH/OMB)
American Indian or Alaska Native
4 Participants
Race (NIH/OMB)
Asian
31 Participants
Race (NIH/OMB)
Black or African American
17 Participants
Race (NIH/OMB)
More than one race
0 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
1 Participants
Race (NIH/OMB)
Unknown or Not Reported
4 Participants
Race (NIH/OMB)
White
256 Participants
Region of Enrollment
Australia
246 participants
Region of Enrollment
United States
56 participants
Sex: Female, Male
Female
372 Participants
Sex: Female, Male
Male
116 Participants
Total Macular Volume8.78 mm
STANDARD_DEVIATION 0.36

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
0 / 3010 / 299
other
Total, other adverse events
274 / 301268 / 299
serious
Total, serious adverse events
23 / 30117 / 299

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Apr 18, 2026