A Phase 3 interventional study of voxelotor and Placebo in Sickle Cell Disease, sponsored by Pfizer. Completed at 62 sites in 12 countries. Open to participants aged 12 Years to 65 Years. Per ClinicalTrials.gov, last updated 2023-07-27.
Sponsored by Pfizer · Phase 3, Interventional, and Treatment
A Phase 3, Double-blind, Randomized, Placebo-controlled, Multicenter Study of Voxelotor Administered Orally to Patients With Sickle Cell Disease
This is a randomized, placebo-controlled, double blind, parallel group, multicenter study of participants, age 12 to 65 years, with SCD. The key purpose for the study is to establish efficacy and safety of voxelotor as compared with placebo.
1,134 studies on the registry are indexed under Anemia, Sickle Cell; 238 are open to participants now.
This study's enrollment of 449 is above the median of 40 across 769 interventional studies indexed under Anemia, Sickle Cell.
Browse Anemia, Sickle Cell studies →Pfizer is the lead sponsor of 3,334 studies on the registry; 149 are open to participants now.
Of its 601 completed or terminated interventional studies of FDA-regulated products, 391 (65%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Hemoglobin (Hb)
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ALT and AST (liver enzymes)
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ULN (upper limit of normal)
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
voxelotor
Drug: voxelotor
voxelotor
Drug: voxelotor
Placebo
Other: Placebo
Also known as: GBT440
Number of Participants With Increase in Hb >1 g/dL From Baseline to Week 24
Number of participants with increase in Hb \>1 g/dL from Baseline to Week 24
Time frame: Baseline to Week 24
Annualized Vaso-Occlusive Crisis (VOC) Incidence Rate
Number of Vaso-Occlusive Crisis (VOC) events averaged per year.
Time frame: Baseline to Week 72
Percentage Change From Baseline in Hemolysis Measures
Percentage change from Baseline to week 24 in unconjugated bilirubin
Time frame: Baseline to Week 24
Percentage Change From Baseline in Hemolysis Measures
Percentage change from Baseline to week 24 in the absolute reticulocyte which is used to estimate the degree of effective erythropoiesis. This values is important in Sickle Cell Disease and was reported by the central laboratory.
Time frame: Baseline to Week 24
Percentage Change From Baseline in Hemolysis Measures
Percentage change from Baseline to week 24 in reticulocytes % which is a % of total Red Blood Cells (RBCs).
Time frame: Baseline to Week 24
Percentage Change From Baseline in Hemolysis Measures
Percentage change from Baseline to week 24 in Lactate Dehydrogenase (LDH)
Time frame: Baseline to Week 24
Overall, 449 subjects were screened for this study at 60 study sites. Between January 2017 and May 2018, a total of 274 subjects were randomized at 58 study sites across 12 countries. All 274 randomized subjects were included in the ITT Population. A total of 271 subjects received study drug and were included in the Safety Population.
| Milestone | Voxelotor 900mg | Voxelotor 1500mg | Placebo |
|---|---|---|---|
| Started | 92 | 90 | 92 |
| Completed | 70 | 63 | 66 |
| Not completed | 22 | 27 | 26 |
| Withdrew: Adverse event | 6 | 11 | 6 |
| Withdrew: Withdrawal by subject | 12 | 6 | 10 |
| Withdrew: Lost to follow-up | 1 | 1 | 0 |
| Withdrew: Physician decision | 2 | 1 | 1 |
| Withdrew: Non-compliance | 1 | 5 | 3 |
| Withdrew: Pregnancy | 0 | 0 | 1 |
| Withdrew: Other | 0 | 3 | 5 |
Number of participants with increase in Hb \>1 g/dL from Baseline to Week 24
| Participants | Voxelotor 900 mg | Voxelotor 1500 mg | Placebo |
|---|---|---|---|
| Number of Participants With Increase in Hb >1 g/dL From Baseline to Week 24 | 30 | 46 | 6 |
Number of Vaso-Occlusive Crisis (VOC) events averaged per year.
| Events per year | Voxelotor 900 mg | Voxelotor 1500 mg | Placebo |
|---|---|---|---|
| Annualized Vaso-Occlusive Crisis (VOC) Incidence Rate | 2.4 (1.9 to 3.1) | 2.4 (1.8 to 3.1) | 2.8 (2.2 to 3.6) |
Percentage change from Baseline to week 24 in unconjugated bilirubin
| percentage change | Voxelotor 900 mg | Voxelotor 1500 mg | Placebo |
|---|---|---|---|
| Percentage Change From Baseline in Hemolysis Measures | -20.1 ± 3.41 | -29.1 ± 3.46 | -2.8 ± 3.51 |
Percentage change from Baseline to week 24 in the absolute reticulocyte which is used to estimate the degree of effective erythropoiesis. This values is important in Sickle Cell Disease and was reported by the central laboratory.
| percentage change | Voxelotor 900 mg | Voxelotor 1500 mg | Placebo |
|---|---|---|---|
| Percentage Change From Baseline in Hemolysis Measures | 4.7 ± 5.13 | -6.4 ± 5.17 | 4.7 ± 5.19 |
Percentage change from Baseline to week 24 in reticulocytes % which is a % of total Red Blood Cells (RBCs).
| Percentage Change | Voxelotor 900 mg | Voxelotor 1500 mg | Placebo |
|---|---|---|---|
| Percentage Change From Baseline in Hemolysis Measures | -1.4 ± 4.65 | -18.0 ± 4.70 | 6.8 ± 4.73 |
Percentage change from Baseline to week 24 in Lactate Dehydrogenase (LDH)
| Percentage Change | Voxelotor 900 mg | Voxelotor 1500 mg | Placebo |
|---|---|---|---|
| Percentage Change From Baseline in Hemolysis Measures | 1.6 ± 3.68 | -4.6 ± 3.69 | 3.0 ± 3.75 |
Collected over 72 Weeks. Non-serious events are listed at a 5% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Voxelotor 900 mg | 2/92 (2.2%) | 20/92 (21.7%) | 85/92 (92.4%) |
| Voxelotor 1500 mg | 2/88 (2.3%) | 25/88 (28.4%) | 85/88 (96.6%) |
| Placebo | 2/91 (2.2%) | 23/91 (25.3%) | 81/91 (89%) |
| Event | Voxelotor 900 mg | Voxelotor 1500 mg | Placebo |
|---|---|---|---|
| PyrexiaGeneral disorders | 3/92 | 2/88 | 3/91 |
| AnaemiaBlood and lymphatic system disorders | 3/92 | 0/88 | 2/91 |
| MalariaInfections and infestations | 3/92 | 1/88 | 0/91 |
| Pleural effusionRespiratory, thoracic and mediastinal disorders | 0/92 | 2/88 | 0/91 |
| Pulmonary embolismRespiratory, thoracic and mediastinal disorders | 0/92 | 2/88 | 1/91 |
| GastritisGastrointestinal disorders | 2/92 | 0/88 | 0/91 |
| Musculoskeletal chest painMusculoskeletal and connective tissue disorders | 2/92 | 0/88 | 1/91 |
| HypersplenismBlood and lymphatic system disorders | 0/92 | 1/88 | 0/91 |
| ReticulocytopeniaBlood and lymphatic system disorders | 0/92 | 1/88 | 0/91 |
| Cardiac failure high outputCardiac disorders | 0/92 | 1/88 | 0/91 |
| Event | Voxelotor 900 mg | Voxelotor 1500 mg | Placebo |
|---|---|---|---|
| HeadacheNervous system disorders | 20/92 | 27/88 | 23/91 |
| Upper respiratory tract infectionInfections and infestations | 22/92 | 12/88 | 13/91 |
| DiarrhoeaGastrointestinal disorders | 17/92 | 20/88 | 10/91 |
| Pain in extremityMusculoskeletal and connective tissue disorders | 20/92 | 12/88 | 19/91 |
| ArthralgiaMusculoskeletal and connective tissue disorders | 14/92 | 18/88 | 13/91 |
| PainGeneral disorders | 15/92 | 15/88 | 18/91 |
| NauseaGastrointestinal disorders | 17/92 | 16/88 | 9/91 |
| Back painMusculoskeletal and connective tissue disorders | 12/92 | 15/88 | 12/91 |
| VomitingGastrointestinal disorders | 13/92 | 11/88 | 15/91 |
| Abdominal pain upperGastrointestinal disorders | 14/92 | 8/88 | 6/91 |
| Age, Customized(Participants) | Voxelotor 900mg | Voxelotor 1500mg | Placebo | Total |
|---|---|---|---|---|
| 12 to < 18 | 15 | 14 | 17 | 46 |
| >=18 to < 65 | 77 | 76 | 75 | 228 |
| Sex: Female, Male(Participants) | Voxelotor 900mg | Voxelotor 1500mg | Placebo | Total |
|---|---|---|---|---|
| Female | 51 | 58 | 50 | 159 |
| Male | 41 | 32 | 42 | 115 |
| Ethnicity (NIH/OMB)(Participants) | Voxelotor 900mg | Voxelotor 1500mg | Placebo | Total |
|---|---|---|---|---|
| Hispanic or Latino | 4 | 3 | 3 | 10 |
| Not Hispanic or Latino | 86 | 82 | 85 | 253 |
| Unknown or Not Reported | 2 | 5 | 4 | 11 |
| Race/Ethnicity, Customized(Participants) | Voxelotor 900mg | Voxelotor 1500mg | Placebo | Total |
|---|---|---|---|---|
| Race — Arab/Middle Eastern | 19 | 15 | 18 | 52 |
| Race — Black or African American | 60 | 59 | 63 | 182 |
| Race — White | 6 | 7 | 3 | 16 |
| Race — Asian | 0 | 1 | 0 | 1 |
| Race — Other | 4 | 2 | 5 | 11 |
| Race — Multiple | 2 | 5 | 3 | 10 |
| Race — Missing/ Not Specified | 1 | 1 | 0 | 2 |
| Region of Enrollment(participants) | Voxelotor 900mg | Voxelotor 1500mg | Placebo | Total |
|---|---|---|---|---|
| Europe | 19 | 19 | 18 | 56 |
| North America | 36 | 34 | 35 | 105 |
| Egypt | 15 | 16 | 13 | 44 |
| Kenya | 17 | 14 | 18 | 49 |
| Jamaica | 0 | 2 | 2 | 4 |
| Oman | 2 | 2 | 5 | 9 |
| Lebanon | 3 | 3 | 1 | 7 |
PDFs hosted by the registry, ClinicalTrials.gov.
Plan to share: No
Ran from Dec 2016 to primary completion in Oct 2019, 34 months.
Results were first posted in Jan 2021, 1 year 2 months after primary completion.
Of 35 phase 3 interventional studies under Anemia, Sickle Cell, half reached primary completion within 48 months of starting (the median), counting those still running; a quarter within 36 and three quarters within 61. This study's 34 months is below that.
How these figures are worked out, and which studies are left out of them.
This study is completed, as verified in Jul 2023. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: Voxelotor