18 and older, any sex, with B-Thalassemia. Patients with the condition only — healthy volunteers not accepted.
Results — posted to ClinicalTrials.gov
Per-arm endpoint measurements with 95% confidence intervals where reported. Source: trial results section.
Percentage of Non-transfusion Dependent (NTD) Participants With a Hemoglobin Increase of ≥1.5 g/dL From Baseline for ≥14 DaysPrimary· Up to approximately 20 weeks
An erythroid response in NTD participants was defined as a mean hemoglobin increase of ≥1.5 g/dL from baseline for ≥14 days in the absence of blood transfusion. Baseline hemoglobin for NTD participants was the average of two or more measurements performed during the screening period. Hemoglobin measurements within 2 weeks following red blood cell (RBC) transfusion or 56 days after the last dose were excluded from analysis. NTD participants were participants who had received \<4 units of RBCs within 8 weeks prior to the first dose of study drug. The percentage of participants with a hemoglobin
Group
Value
95% CI
Luspatercept 0.2 mg/kg
0.0
0.0 – 45.9
Luspatercept 0.4 mg/kg
0.0
0.0 – 45.9
Luspatercept 0.6 mg/kg
0.0
0.0 – 52.2
Luspatercept 0.8 mg/kg
66.7
9.4 – 99.2
Luspatercept 1.0 mg/kg
50.0
1.3 – 98.7
Luspatercept 1.25 mg/kg
0.0
0.0 – 97.5
Expansion Cohort
60.0
26.2 – 87.8
Percentage of Transfusion Dependent (TD) Participants With a ≥20% Reduction in Red Blood Cell (RBC) Transfusion Burden From Baseline During a Rolling 12-week IntervalPrimary· Any 12-week interval during the study (up to approximately 20 weeks)
Transfusion burden for TD participants was defined as the ratio of RBC transfusion units (or milliliters) transfused during a 12-week interval divided by the duration of that interval compared to the ratio of RBC transfusion units 12 weeks prior to the start of treatment (baseline). The interval during the pretreatment period was defined as the 12 weeks prior to the first dose of study drug. An interval during the treatment plus follow-up period was defined as any 12-week interval after the first dose of study drug. TD participants were participants who had received ≥4 units of RBCs every 8 we
Group
Value
95% CI
Luspatercept 0.6 mg/kg
100
2.5 – 100
Luspatercept 0.8 mg/kg
66.7
9.4 – 99.2
Luspatercept 1.0 mg/kg
100
39.8 – 100
Luspatercept 1.25 mg/kg
75.0
19.4 – 99.4
Expansion Cohort
78.9
54.4 – 93.9
Number of Participants Who Experienced an Adverse Event (AE)Secondary· Up to approximately 20 weeks
An AE was any untoward medical occurrence in a participant or clinical investigation participant administered a study drug, which does not necessarily have a causal relationship with this treatment. An AE could therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of the study drug whether or not it is considered related to the study drug. The number of participants who experienced an AE is presented.
Group
Value
95% CI
Luspatercept 0.2 mg/kg
5
Luspatercept 0.4 mg/kg
6
Luspatercept 0.6 mg/kg
5
Luspatercept 0.8 mg/kg
6
Luspatercept 1.0 mg/kg
6
Luspatercept 1.25 mg/kg
5
Expansion Cohort
26
Number of Participants Who Experienced a Serious Adverse Event (SAE)Secondary· Up to approximately 20 weeks
An SAE was any adverse event, occurring at any dose level/regimen and regardless of causality that: resulted in death; was life-threatening; required inpatient hospitalization or prolongation of existing hospitalization; resulted in persistent or significant disability/incapacity; was a congenital anomaly/birth defect; or was an important medical event. The number of participants who experienced an SAE is presented.
Group
Value
95% CI
Luspatercept 0.2 mg/kg
0
Luspatercept 0.4 mg/kg
1
Luspatercept 0.6 mg/kg
0
Luspatercept 0.8 mg/kg
0
Luspatercept 1.0 mg/kg
0
Luspatercept 1.25 mg/kg
0
Expansion Cohort
0
Number of Participants Who Experienced an Adverse Event (AE) of Grade 3 or GreaterSecondary· Up to approximately 20 weeks
AEs were graded using the National Cancer Institute Common Toxicity Criteria for Adverse Events, Version 4.0 (NCI-CTCAE v4.0) and graded as follows: Grade 1=mild; Grade 2=moderate; Grade 3=severe or medically significant but not immediately life-threatening; Grade 4=life-threatening consequences; and Grade 5=death related to AE. An AE was any untoward medical occurrence in a participant or clinical investigation participant administered a study drug, which does not necessarily have a causal relationship with this treatment. An AE could therefore be any unfavorable and unintended sign (includin
Group
Value
95% CI
Luspatercept 0.2 mg/kg
0
Luspatercept 0.4 mg/kg
1
Luspatercept 0.6 mg/kg
0
Luspatercept 0.8 mg/kg
1
Luspatercept 1.0 mg/kg
2
Luspatercept 1.25 mg/kg
0
Expansion Cohort
4
Number of Participants Who Discontinued Study Treatment Due To an Adverse Event (AE)Secondary· Up to approximately 12 weeks
An AE was any untoward medical occurrence in a participant or clinical investigation participant administered a study drug, which does not necessarily have a causal relationship with this treatment. An AE could therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of the study drug whether or not it is considered related to the study drug. The number of participants who discontinued study treatment due to an AE is presented.
Group
Value
95% CI
Luspatercept 0.2 mg/kg
0
Luspatercept 0.4 mg/kg
0
Luspatercept 0.6 mg/kg
1
Luspatercept 0.8 mg/kg
2
Luspatercept 1.0 mg/kg
0
Luspatercept 1.25 mg/kg
0
Expansion Cohort
2
Number of Participants Who Experienced a Dose-Limiting Toxicity (DLT)Secondary· Up to 28 days
DLTs were determined using the National Cancer Institute Common Toxicity Criteria for Adverse Events, Version 4.0 (NCI-CTCAE v4.0) and graded as follows: Grade 1=mild; Grade 2=moderate; Grade 3=severe or medically significant but not immediately life-threatening; Grade 4=life-threatening consequences; and Grade 5=death related to AE. The occurrence of any of the following toxicities occurring up to 28 days after the first dose was considered a DLT: treatment-related serious adverse event (SAE) ≥ Grade 3; treatment related non-hematologic adverse event (AE) ≥ Grade 3; and treatment related hema
Group
Value
95% CI
Luspatercept 0.2 mg/kg
0
Luspatercept 0.4 mg/kg
0
Luspatercept 0.6 mg/kg
0
Luspatercept 0.8 mg/kg
1
Luspatercept 1.0 mg/kg
0
Luspatercept 1.25 mg/kg
0
Expansion Cohort
0
Percentage of Non-transfusion Dependent (NTD) Participants With a Hemoglobin Increase of ≥1.0 g/dL From Baseline During a Rolling 8-week IntervalSecondary· Any 8-week interval during the study (up to approximately 20 Weeks)
A modified erythroid response in NTD participants was defined as a mean hemoglobin increase of ≥1.0 g/dL from baseline during an 8-week interval compared to baseline. Baseline hemoglobin for NTD participants was the average of two or more measurements performed during the screening period. Hemoglobin measurements within 2 weeks following red blood cell (RBC) transfusion or 56 days after the last dose were excluded from analysis. NTD participants were participants who had received \<4 units of red blood cells (RBCs) within 8 weeks prior to the first dose of study drug. An 8-week interval was de
Group
Value
95% CI
Luspatercept 0.2 mg/kg
16.7
0.4 – 64.1
Luspatercept 0.4 mg/kg
16.7
0.4 – 64.1
Luspatercept 0.6 mg/kg
80.0
28.4 – 99.5
Luspatercept 0.8 mg/kg
66.7
9.4 – 99.2
Luspatercept 1.0 mg/kg
50.0
1.3 – 98.7
Luspatercept 1.25 mg/kg
0.0
0.0 – 97.5
Expansion Cohort
70.0
34.8 – 93.3
Percentage of Non-transfusion Dependent (NTD) Participants With a Hemoglobin Increase of ≥1.5 g/dL From Baseline During a Rolling 8-week IntervalSecondary· Any 8-week interval during the study (up to approximately 20 Weeks)
A modified erythroid response in NTD participants was defined as a mean hemoglobin increase of ≥1.5 g/dL from baseline during an 8-week interval compared to baseline. Baseline hemoglobin for NTD participants was the average of two or more measurements performed during the screening period. Hemoglobin measurements within 2 weeks following red blood cell (RBC) transfusion or 56 days after the last dose were excluded from analysis. NTD participants were participants who had received \<4 units of red blood cells (RBCs) within 8 weeks prior to the first dose of study drug. An 8-week interval was de
Group
Value
95% CI
Luspatercept 0.2 mg/kg
0.0
0.0 – 45.9
Luspatercept 0.4 mg/kg
0.0
0.0 – 45.9
Luspatercept 0.6 mg/kg
0.0
0.0 – 52.2
Luspatercept 0.8 mg/kg
33.3
0.8 – 90.6
Luspatercept 1.0 mg/kg
50.0
1.3 – 98.7
Luspatercept 1.25 mg/kg
0.0
0.0 – 97.5
Expansion Cohort
60.0
26.2 – 87.8
Percentage of Non-transfusion Dependent (NTD) Participants With a Hemoglobin Increase of ≥1.0 g/dL From Baseline During a Rolling 12-week IntervalSecondary· Any 12-week interval during the study (up to approximately 20 Weeks)
A modified erythroid response in NTD participants was defined as a mean hemoglobin increase of ≥1.0 g/dL from baseline during a 12-week interval compared to baseline. Baseline hemoglobin for NTD participants was the average of two or more measurements performed during the screening period. Hemoglobin measurements within 2 weeks following red blood cell (RBC) transfusion or 56 days after the last dose were excluded from analysis. NTD participants were participants who had received \<4 units of red blood cells (RBCs) within 8 weeks prior to the first dose of study drug. A 12-week interval was de
Group
Value
95% CI
Luspatercept 0.2 mg/kg
16.7
0.4 – 64.1
Luspatercept 0.4 mg/kg
0.0
0.0 – 45.9
Luspatercept 0.6 mg/kg
80.0
28.4 – 99.5
Luspatercept 0.8 mg/kg
66.7
9.4 – 99.2
Luspatercept 1.0 mg/kg
50.0
1.3 – 98.7
Luspatercept 1.25 mg/kg
0.0
0.0 – 97.5
Expansion Cohort
60.0
26.2 – 87.8
Percentage of Non-transfusion Dependent (NTD) Participants With a Hemoglobin Increase of ≥1.5 g/dL From Baseline During a Rolling 12-week IntervalSecondary· Any 12-week interval during the study (up to approximately 20 Weeks)
A modified erythroid response in NTD participants was defined as a mean hemoglobin increase of ≥1.5 g/dL from baseline during a 12-week interval compared to baseline. Baseline hemoglobin for NTD participants was the average of two or more measurements performed during the screening period. Hemoglobin measurements within 2 weeks following red blood cell (RBC) transfusion or 56 days after the last dose were excluded from analysis. NTD participants were participants who had received \<4 units of red blood cells (RBCs) within 8 weeks prior to the first dose of study drug. A 12-week interval was de
Group
Value
95% CI
Luspatercept 0.2 mg/kg
0.0
0.0 – 45.9
Luspatercept 0.4 mg/kg
0.0
0.0 – 45.9
Luspatercept 0.6 mg/kg
0.0
0.0 – 52.2
Luspatercept 0.8 mg/kg
33.3
0.8 – 90.6
Luspatercept 1.0 mg/kg
50.0
1.3 – 98.7
Luspatercept 1.25 mg/kg
0.0
0.0 – 97.5
Expansion Cohort
50.0
18.7 – 81.3
Percentage of Transfusion Dependent (TD) Participants With a ≥50% Reduction in Red Blood Cell (RBC) Transfusion Burden From Baseline During a Rolling 8-week IntervalSecondary· Any 8-week interval during the study (up to approximately 20 weeks)
Transfusion burden for TD participants was defined as the ratio of RBC transfusion units (or milliliters) transfused during an 8-week interval divided by the duration of that interval compared to the ratio of RBC transfusion units 8 weeks prior to the start of treatment (baseline). TD participants were participants who had received ≥4 units of RBCs every 8 weeks (confirmed over 6 months prior to the first dose of study drug). An 8-week interval was defined as any consecutive 8 weeks during the study. The percentage of participants with a ≥50% reduction in RBC transfusion burden from baseline i
Group
Value
95% CI
Luspatercept 0.6 mg/kg
100
2.5 – 100
Luspatercept 0.8 mg/kg
100
29.2 – 100
Luspatercept 1.0 mg/kg
100
39.8 – 100
Luspatercept 1.25 mg/kg
75.0
19.4 – 99.4
Expansion Cohort
78.9
54.4 – 93.9
Adverse events — posted to ClinicalTrials.gov
Time frame: Up to approximately 20 weeks.
Reporting threshold: 5%.
Adverse-event reports describe events observed during the trial — not all are caused by the drug.
The purpose of this study is to evaluate the efficacy, safety, and pharmacokinetics, of ascending doses of luspatercept in participants with β-thalassemia.
The primary objective of this study is to evaluate erythroid response, defined as:
1. a hemoglobin increase of ≥ 1.5 g/dL from baseline for ≥ 14 days (in the absence of red blood cell \[RBC\] transfusions) in non-transfusion dependent participants, or
2. a ≥ 20% reduction in RBC transfusion burden compared to pretreatment in transfusion dependent participants.
Publications & conference data
8 peer-reviewed publications reference this trial (live from Europe PMC):
NCT06164821 — Clinical Observation of Luspatercept in Treatment of Chinese Adult β-thalassaemia Patients With TD β-thalassemia
· NA
· unknown
NCT02268409 — Extension Study to Evaluate the Safety and Efficacy of Luspatercept in Participants With β-Thalassemia Previously Enroll
· Phase 2
· completed
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Publications: Europe PMC API search by NCT ID, retrieved 10 June 2026
Drug + disease cross-links: matched in real time against Drug Landscape's normalised drug + company + condition tables
Sponsor: as reported to ClinicalTrials.gov by Acceleron Pharma, Inc., a wholly-owned subsidiary of Merck & Co., Inc., Rahway, NJ USA
Last refreshed: 18 July 2024
Drug Landscape aggregates and links these public records for informational use only. Always verify against the primary source before clinical or regulatory decisions. Canonical URL: https://druglandscape.com/trial/NCT01749540.