Review the clinical results
ZYNTEGLO® has been studied in two 24-month phase 3 clinical trials, with an ongoing 13-year long-term
follow-up study.1
- Patients enrolled in the clinical trials had a diagnosis of beta-thalassemia and received regular RBC transfusions (a history of at least 100 mL/kg/year of RBCs or ≥8 transfusions of RBCs per year for the prior 2 years)
41
41
patients treated
with ZYNTEGLO
2
2
open-label, single-arm
clinical trials
Primary outcome for Study 1 (HGB-207) and Study 2 (HGB-212): Transfusion independence1,2
- Median age: 13 years old (min, max: 4, 34)
- Genotype:
- Study 1: 23 non-β0/β0
- Study 2: 12 β0/β0 and 6 non-β0/β0 (Non-β0/β0 patients were IVS-I-110 homozygous or β0/IVS-I-110)
89% (n=32/36) of patients across ages and genotypes achieved transfusion independence with a normal or near-normal median total Hb of 11.5 g/dL1*†
- Transfusion independence (89%; 95% CI: 74, 97)
- Weighted average total Hb during transfusion independence (median 11.5 g/dL; min, max 9.3, 13.7)
The two phase 3 studies are ongoing. All data is as of March 2021.1
All patients (n=32/32) who achieved transfusion independence maintained it.
Min, max duration of ongoing transfusion independence of 12.5+, 39.4+ months; median duration of transfusion independence not reached.‡
*Across clinical trials, patient evaluability for transfusion independence (n=36) was defined as patients who have completed their parent study (ie, 24 months of follow-up), achieved transfusion independence, or will not achieve transfusion independence in their parent study.1
†Normal Hb ranges for healthy individuals from the American College of Clinical Pharmacy3:
- 2–9 years: 11.5–14.5 g/dL
- Males 10–17 years: 12.5–16.1 g/dL
- Females 10–17 years: 12–15 g/dL
- Male adults (≥18 years): 13.5–18 g/dL
- Female adults (≥18 years): 12.5–16 g/dL
- 2–9 years: 11.5–14.5 g/dL
- Males 10–17 years: 12.5–16.1 g/dL
- Females 10–17 years: 12–15 g/dL
- Male adults (≥18 years): 13.5–18 g/dL
- Female adults (≥18 years): 12.5–16 g/dL
‡Data beyond 24 months are from the long-term follow-up study, Study 3 (LTF-303).1
All patients who achieved transfusion independence maintained it with durable normal or near-normal total Hb levels1
Median unsupported total Hb was 11.4 g/dL (min, max: 9.5, 14.8) at last follow-up (N=32)
Median total Hb in patients treated with ZYNTEGLO who have achieved transfusion independence4*†
This figure is not included in the USPI.
*Bars represent interquartile ranges.
†Unsupported total Hb represents those without any pRBC transfusions within 60 days prior to the measurement date. Transfusion independence defined as weighted average hemoglobin ≥9 g/dL without any pRBC transfusions for ≥12 months.1
‡Data beyond 24 months are from the long-term follow-up study, Study 3 (LTF-303).1
Maximum duration of follow-up was 42 months (N=5), median unsupported total Hb in these
five patients at last follow-up was 13.3 (min, max: 11.1, 13.7) g/dL5
Prespecified subgroup analysis:
Majority of adult patients (≥18 years of age) across genotypes achieved
transfusion independence with normal or near-normal median total Hb levels6*†
The two phase 3 studies are ongoing. All data is as of March 2021.
All adult patients (n=12/12) who achieved transfusion independence maintained it. Min, max duration of ongoing transfusion independence of 13.1+, 39.4+ months; median duration of transfusion independence not reached‡
Adult subgroup data are not in the USPI. Efficacy in subgroups was not a study objective. There was no hypothesis testing.
*Transfusion independence was defined as weighted average hemoglobin ≥9 g/dL without any packed red blood cell (pRBC) transfusions for ≥12 months.1
†Across clinical trials, patient evaluability for transfusion independence (n=36) was defined as patients who have completed their parent study (ie, 24 months of follow-up), achieved transfusion independence, or will not achieve transfusion independence in their parent study.1
‡Data beyond 24 months are from the long-term study, Study 3 (LTF-303).1
Prespecified subgroup analysis:
Majority of pediatric patients (aged 4 to 17) across genotypes achieved
transfusion independence with normal or near-normal median total Hb levels7*†
The two phase 3 studies are ongoing. All data is as of March 2021.
All pediatric patients (n=20/20) who achieved transfusion independence maintained it.
Min, max duration of ongoing transfusion independence of 12.5+, 37.9+ months; median duration of transfusion independence not reached‡
Pediatric subgroup data are not in the USPI. Efficacy in subgroups was not a study objective. There was no hypothesis testing.
*Transfusion independence was defined as weighted average hemoglobin ≥9 g/dL without any pRBC transfusions for ≥12 months.1
†Across clinical trials, pediatric patient evaluability for transfusion independence (n=22) was defined as patients who have completed their parent study (ie, 24 months of follow-up), have achieved transfusion independence, or will not achieve transfusion independence in their parent study.1
‡Data beyond 24 months are from the long-term follow-up study, Study 3 (LTF-303).1
The majority of patients (20/32) who achieved transfusion independence are not receiving chelation as of last follow-up1
Restarting iron chelation after ZYNTEGLO infusion may be necessary and should be based on clinical practice*
The two phase 3 studies are ongoing. All data is as of March 2021.1
Of those 13 patients
- 9 did not restart chelation post-ZYNTEGLO infusion
- 4 restarted and then stopped with a median time from last iron chelation use to last follow-up of 22.7 months (min, max: 7.1, 23.4)
Of the 20 patients who achieved transfusion independence, 7 patients (35.0%) received phlebotomy to remove iron1
Of those 7 patients
- 3 did not restart chelation post-ZYNTEGLO infusion
- 4 restarted and then stopped with a median time from last iron chelation use to last follow-up of 7.2 months (min, max: 6.0, 21.4)
Of the 12 patients who achieved transfusion independence, 1 patient (8%) received phlebotomy to remove iron
*Prior to initiation of conditioning for ZYNTEGLO, iron removal therapies should be stopped for at least 7 days. In the clinical studies, iron removal therapy after ZYNTEGLO infusion was managed at physician discretion.1
Median time to last RBC transfusion prior to transfusion independence was <1 month1*
Study 1 (median): 0.9 months (n=20; min, max: 0.5, 2.4 months)
Study 2 (median): 0.8 months (n=12; min, max: 0.0, 1.9 months)
*Transfusion independence was defined as weighted average hemoglobin ≥9 g/dL without any pRBC transfusions for ≥12 months.1
Patients who were evaluable for transfusion independence but did not achieve it experienced transfusion reductions1*
Reductions were observed from 6 months post-ZYNTEGLO infusion to last follow-up compared to pre-enrollment requirements
The two phase 3 studies are ongoing. All data is as of March 2021.1
STUDY 1: (n=2/22†)
Patient 3A |
|
| Transfusion frequency: | 30% reduction |
| Transfusion volume: | 32% reduction |
Patient 3B |
|
| Transfusion frequency: | 26% reduction |
| Transfusion volume: | 31% reduction |
| Transfusion volume: | 31% reduction |
STUDY 2: (n=2/14†)
Patient 3C |
|
| Transfusion frequency: | 87% reduction |
| Transfusion volume: | 92% reduction |
Patient 3D |
|
| Transfusion frequency: | 21% reduction |
| Transfusion volume: | 3% reduction |
| Transfusion volume: | 3% reduction |
*Transfusion independence was defined as weighted average Hb of ≥9 g/dL without any pRBC transfusions for ≥12 months.1
†Data shown here are for patients who are currently evaluable for assessment of transfusion independence as of March 2021.
Explore Next