REBLOZYL was studied in the multicenter, randomized, double-blind, placebo-controlled, phase 3 BELIEVE trial1,2
All patients in the pivotal phase 3 BELIEVE trial received regular RBC transfusions1
REBLOZYL provided substantial clinical benefit by reducing RBC transfusion burden1
Primary endpoint subgroup analysis:
Reduction in RBC transfusion burden with REBLOZYL2

Key secondary endpoints:
Clinically meaningful reductions in transfusion burden were seen with REBLOZYL1

Additional analysis: Reductions in transfusion burden during any consecutive 24-week period with REBLOZYL*
Reduction in transfusion burden from baseline during any consecutive 24-week period2*
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 specific 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 limitations
- Patients may have experienced multiple periods of response intermittently between periods without response over the 48-week assessment period2
- 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 study2
- 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; and nutritional support1

This analysis looks at the reduction in transfusion burden over a longer period of time, which may be important in adult patients with β-thalassemia who require regular transfusions2
Additional analysis: Time to response and total cumulative duration of response at 48 weeks
Time from the first dose to response and total (cumulative) duration of response during any consecutive 12-week period2
REBLOZYL (n = 224) |
Placebo (n = 112) |
|
Patients with ≥33% transfusion burden reduction 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 limitations
- Patients may have experienced multiple periods of response intermittently between periods without response over the 48-week assessment period2
- 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 study2
- 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 period2
- Each response period was a continuous period in which a subject had response during any 12-week interval2
- The median treatment exposure was approximately 64 weeks in both groups2
- 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