| Demographic and disease characteristics |
REBLOZYL + BSC (n=224) |
Placebo + BSC (n=112) |
|---|---|---|
| Age, years | ||
| Median (min, max) | 30.0 (18, 66) | 30.0 (18, 59) |
| Baseline transfusion burden 12 weeks prior to randomization, units/12 weeks | ||
| Median (min, max) | 6.12 (3, 14) | 6.27 (3, 12) |
| Beta-thalassemia gene mutation grouping, n (%) | ||
| ß0/ß0 | 68 (30.4) | 35 (31.3) |
| Non-ß0/ß0 | 155 (69.2) | 77 (68.8) |
| Missing* | 1(0.4) | 0 |
| Baseline serum ferritin level, ug/L | ||
| N | 220 | 111 |
| Median (min, max) | 1441.25 (88, 6400) | 1301.50 (136, 6400) |
| Splenectomy, n (%) | ||
| Yes | 129 (57.6) | 65 (58) |
| No | 95 (42.4) | 47 (42) |
| Sex, n (%) | ||
| Male | 92 (41.1) | 49 (43.7) |
| Female | 132 (58.9) | 63 (56.3) |
| Beta-thalassemia diagnosis, n (%) | ||
| ß-thalassemia | 174 (77.7) | 83 (74.1) |
| HbE/ß-thalassemia | 31 (13.8) | 21 (18.8) |
| ß-thalassemia combined with α-thalassemia | 18 (8) | 8 (7.1) |
| Missing* | 1 (0.4) | 1 |
PATIENT OUTCOMES: EFFICACY
REBLOZYL provided substantial clinical benefit by reducing RBC transfusion burden1,2
The efficacy of REBLOZYL in patients with beta-thalassemia was demonstrated in the BELIEVE trial
Study design: REBLOZYL was studied in the pivotal Phase 3 BELIEVE trial of 336 adult patients with beta-thalassemia requiring regular RBC transfusions (6-20 RBC units per 24 weeks) with no transfusion-free period greater than 35 days during that period who were randomized 2:1 to REBLOZYL (n=224) or placebo (n=112). In BELIEVE, REBLOZYL was administered subcutaneously once every 3 weeks as long as a reduction in transfusion requirement was observed or until unacceptable toxicity. Patients were able to receive BSC as needed, including: RBC transfusions; iron-chelating agents; use of antibiotic, antiviral, and antifungal therapy; and nutritional support. The exclusion criteria for this trial included HbS/beta-thalassemia or alpha-thalassemia; major organ damage (liver, heart, or lung disease, or renal insufficiency); recent deep vein thrombosis or stroke; or recent use of ESA, immunosuppressant, or hydroxyurea therapy. At 48 weeks, patients could cross over to REBLOZYL as part of the long-term follow-up.1,3
REBLOZYL WAS STUDIED IN THE MULTICENTER, RANDOMIZED, DOUBLE-BLIND, PLACEBO-CONTROLLED, PHASE 3 BELIEVE TRIAL
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Patient population (N=336)
Key inclusion criteria:
- Adults ≥18 years of age with β-thalassemia
- Transfusion requirements
- Regular transfusions 6-20 RBC units per 24 weeks
- No transfusion-free period >35 days during that period
Key exclusion criteria:
- HbS/β-thalassemia or isolated α-thalassemia (eg, hemoglobin H)
- Major organ damage (liver disease, heart disease, lung disease, renal insufficiency)
- Recent deep vein thrombosis or stroke
- Recent use of ESA, immunosuppressant, or hydroxyurea therapy
Randomized 2:1 and followed for 48 weeks
REBLOZYL + BSC
1 mg/kg (SC) every 3 weeks, with dose increase allowed to 1.25 mg/kg (n=224)
Placebo + BSC
SC every 3 weeks (n=112)
Long-term follow-up
Optional crossover to REBLOZYL was permitted at 48 weeks
All patients in both arms were eligible to receive best supportive care (BSC) as needed:
- RBC transfusions
- Iron-chelating agents
- Use of antibiotic, antiviral, and antifungal therapy
- Nutritional support
Primary endpoint1
- ≥33% reduction in RBC transfusion burden of at least 2 units from Weeks 13 to 24
Key secondary endpoints1
- ≥50% reduction in RBC transfusion burden from baseline of at least 2 units during Weeks 13 to 24
- ≥33% and ≥50% reductions in RBC transfusion burden to assess the durability of response from baseline of at least 2 units during Weeks 37 to 48
Additional endpoints2
- ≥33% or ≥50% reductions from baseline in RBC transfusion burden during any consecutive 24 weeks
- Duration of reduction in transfusion burden
- Time to erythroid response
All patients in the pivotal Phase 3 BELIEVE trial received regular RBC transfusions1
BASELINE CHARACTERISTICS OF PATIENTS WITH BETA-THALASSEMIA IN THE PIVOTAL PHASE 3 BELIEVE TRIAL (ITT POPULATION)1,2
*Missing category includes patients in the population who had no result for the parameter listed.
The intention-to-treat (ITT) population consisted of all patients, regardless of whether the patient received the study drug.
PRIMARY ENDPOINT: RBC-TI ≥33% REDUCTION FROM BASELINE IN TRANSFUSION BURDEN FROM WEEKS 13 TO 241
KEY SECONDARY ENDPOINTS
Clinically meaningful reductions in transfusion burden were seen with REBLOZYL1
Additional analyses
THIS ANALYSIS LOOKS AT THE REDUCTION IN TRANSFUSION BURDEN OVER A LONGER PERIOD OF TIME, WHICH MAY BE IMPORTANT IN ADULT PATIENTS WITH BETA-THALASSEMIA WHO REQUIRE REGULAR TRANSFUSIONS2,3
| Endpoint | REBLOZYL (n=224) |
Placebo (n=112) |
Risk difference (95% CI) |
|---|---|---|---|
| ≥33% reduction in transfusion burden n (%) |
92 (41.1) | 3 (2.7) | 38.4 (31.3-45.5) |
| ≥50% reduction in transfusion burden n (%) |
37 (16.5) | 1 (0.9) | 15.6 (10.5-20.8) |
*Not restricted by a specified time period.
- The estimated transfusion burden reduction from baseline per patient based on the consecutive 24-week analysis was2:
- 6.55 RBC units per 24 weeks in patients with ≥33% reduction in RBC transfusion burden
- 8.27 RBC units per 24 weeks in patients with ≥50% reduction in RBC transfusion burden
Analysis limitations3
- Patients may have experienced multiple periods of response intermittently between periods without response over the 48-week assessment period
- These exploratory analyses should not be interpreted to determine treatment difference between arms in these select endpoints because of potential selection bias, insufficient sample size, and a higher probability of making a false-positive finding
Additional analysis information
- The total (cumulative) duration of RBC transfusion burden reduction was defined as the sum of individual response periods (≥33% reduction from baseline in RBC transfusion burden of at least 2 units), with overlapping response periods excluded, over the entire 48-week study3
- All patients in both arms were eligible to receive BSC as needed: RBC transfusions; iron-chelating agents; use of antibiotic, antiviral, and antifungal therapy; and nutritional support1
TIME FROM THE FIRST DOSE TO RESPONSE AND TOTAL (CUMULATIVE) DURATION OF RESPONSE DURING ANY CONSECUTIVE 12-WEEK PERIOD3
| REBLOZYL (n=224) |
Placebo (n=112) |
|
|---|---|---|
| Patients with ≥33% transfusion burden from baseline of at least 2 units, n (%) |
158 (70.5) | 33 (29.5) |
| Time to response, median (min, max) | 12 days (2 days, 360 days) |
107 days (2 days, 386 days) |
| Among responders, total cumulative duration of transfusion burden reduction, median (min, max) |
298 days (84 days, 631 days) |
171 days (84 days, 533 days) |
Analysis limitations3
- Patients may have experienced multiple periods of response intermittently between periods without response over the 48-week assessment period
- These exploratory analyses should not be interpreted to determine treatment difference between arms in these select endpoints because of potential selection bias, insufficient sample size, and a higher probability of making a false positive finding
Additional analysis information
- The total (cumulative) duration of RBC transfusion burden reduction was defined as the sum of individual response periods (≥33% reduction from baseline in RBC transfusion burden of at least 2 units), with overlapping response periods excluded, over the entire 48-week study3
- The time to response was defined as the first day of the start of the ≥33% reduction from baseline in RBC transfusion burden of at least 2 units during any rolling 12-week period3
- Each response period was a continuous period in which a subject had response during any 12-week interval3
- The median treatment exposure was approximately 64 weeks in both groups3
- All patients in both arms were eligible to receive BSC as needed: RBC transfusions; iron-chelating agents; use of antibiotic, antiviral, and antifungal therapy; and nutritional support1
BSC=best supportive care; CI=confidence interval; ESA=erythropoiesis-stimulating agent; HbE=hemoglobin E; HbS=hemoglobin S; RBC=red blood cell; RBC-TI=red blood cell transfusion independence; SC=subcutaneous.
Learn about the safety profile of REBLOZYL
References: 1. REBLOZYL [US Prescribing Information]. Summit, NJ: Celgene Corporation; 2026. 2. Cappellini MD, Viprakasit V, Taher AT, et al. A phase 3 trial of luspatercept in patients with transfusion-dependent β-thalassemia. N Engl J Med. 2020;382(13):1219-1231. 3. Data on file. Celgene Corporation. Summit, New Jersey.
