Clinical Pharmacology for Reblozyl
Mechanism Of Action
Luspatercept-aamt is a recombinant fusion protein that binds several endogenous TGF-β superfamily ligands, thereby diminishing Smad2/3 signaling. In models of β-thalassemia and MDS, luspatercept-aamt decreased abnormally elevated Smad2/3 signaling and improved hematology parameters associated with ineffective erythropoiesis in mice. Luspatercept-aamt promoted erythroid maturation through differentiation and increasing the percentage of late-stage erythroid precursors (normoblasts) in the bone marrow of mice and increased erythroid precursors in humans, thereby increasing erythropoiesis.
Pharmacodynamics
Increases In Hemoglobin In Patients With Low RBC Transfusion Burden
In patients having received < 4 units of RBC transfusion within 8 weeks prior to study, hemoglobin increased within 7 days of initiating REBLOZYL and correlated with the time to luspatercept-aamt maximum serum concentration (Cmax). The greatest hemoglobin (Hgb) increase occurred after the first dose; approximately 0.75 g/dL at a dose of 0.6 to 1.25 times the recommended starting dose for beta thalassemia, or approximately 1 g/dL at a dose of 0.75 to 1.75 times the recommended starting dose for MDS. Additional smaller increases were observed after subsequent doses. Hemoglobin levels returned to baseline approximately 6 to 8 weeks from the last dose following administration of luspatercept-aamt (0.6 to 1.75 mg/kg).
Increasing luspatercept-aamt serum exposure (AUC) was associated with greater Hgb increase in patients with beta thalassemia or MDS who had a baseline transfusion burden < 4 units/8 weeks. Increasing luspatercept-aamt serum exposure (time-averaged AUC) was associated with greater probability of achieving transfusion independence for at least 8 consecutive weeks in ESA-refractory or -intolerant patients with MDS requiring transfusions (≥ 2 units of RBC transfusion within 8 weeks).
Pharmacokinetics
Luspatercept-aamt exhibited linear pharmacokinetics (PK) over the dose range of 0.2 to 1.25 mg/kg
(0.2 to 1.25 times the recommended starting dosage) in patients with beta thalassemia, and from 0.125 mg/kg to 1.75 mg/kg (0.125 to 1.75 times the recommended starting dosage) in patients with MDS. The geometric mean (% coefficient of variation [%CV]) steady-state AUC at the starting dose of 1 mg/kg was 126 (35.9%) day•μg/mL for patients with beta thalassemia and 154 (37.4%) day•μg/mL for patients with MDS. Luspatercept-aamt serum concentration reached steady state after 3 doses when administered every 3 weeks. The accumulation ratio of luspatercept-aamt was approximately 1.5.
Absorption
The median [range] time to maximum concentration (Tmax) of luspatercept-aamt was observed at approximately 5 [3 to 8] days post-dose in adult patients with beta thalassemia or 6 [3 to 7] days post-dose in adult patients with MDS. The absorption of luspatercept-aamt was not significantly affected by the subcutaneous injection sites (upper arm, thigh, or abdomen).
Distribution
The geometric mean (%CV) apparent volume of distribution (Vd/F) of luspatercept-aamt was 7.1 (26.7%) L for patients with beta thalassemia and 9.6 (26.7%) L for patients with MDS.
Elimination
The geometric mean (%CV) half-lives (t½) of luspatercept-aamt were approximately 11 (25.7%) days in patients with beta thalassemia and 14 (31.7%) days in patients with MDS. The geometric mean (%CV) apparent total clearance (CL/F) of luspatercept-aamt was 0.44 (38.5%) L/day in patients with beta thalassemia and 0.47 (42.9%) L/day in patients with MDS.
Metabolism
Luspatercept-aamt is expected to be catabolized into small peptides and amino acids by general catabolic degradation processes in multiple tissues.
Specific Populations
No clinically significant differences in the luspatercept-aamt PK were observed based on age (18 to 95 years), sex, race/ethnicity (Asian, White), mild to severe hepatic impairment (total bilirubin ≥ upper limit of normal [ULN] and aspartate aminotransaminase [AST] or alanine transaminase [ALT] > ULN, or total bilirubin > ULN and any AST or ALT), mild to moderate renal impairment (estimated glomerular filtration rate [eGFR] 30 to 89 mL/min), baseline albumin (30 to 56 g/L), baseline serum erythropoietin (2.4 to 2920 U/L), red blood cell (RBC) transfusion burden (0 to 43 units/24 weeks), beta thalassemia genotype (β0/β0 vs. non-β0/β0), splenectomy, and ring sideroblasts status in MDS (negative vs. positive). The effect of AST or ALT >3 x ULN and the effect of severe renal impairment (eGFR <30 mL/min) on luspatercept-aamt PK is unknown.
Body Weight
The apparent CL/F and Vd/F of luspatercept-aamt increased with increasing body weight in patients with beta thalassemia (34 to 97 kg) and in patients with MDS (33 to 124 kg).
Drug Interaction Studies
Effect Of Iron-Chelating Agents On Luspatercept-aamt
No clinically significant differences in luspatercept-aamt PK were observed when used concomitantly with iron-chelating agents.
Immunogenicity
The observed incidence of anti-drug antibodies (ADA) is highly dependent on the sensitivity and specificity of the assay. Differences in assay methods preclude meaningful comparisons of the incidence of anti-drug antibodies in the studies described below with the incidence of anti-drug antibodies in other studies, including those of REBLOZYL or of other luspatercept products.
In the BELIEVE trial, the median duration of exposure was 64 weeks, with a median ADA sampling period of 50 weeks. Of the 220 patients in the BELIEVE trial with beta thalassemia who require regular RBC transfusions treated with REBLOZYL and evaluable for the presence of anti luspatercept-aamt antibodies, 4 patients (1.81%) tested positive for treatment-emergent antiÂluspatercept-aamt antibodies, including 2 patients (0.9%) who had neutralizing antibodies detected. The majority of anti-luspatercept-aamt antibodies were of low titers.
In the COMMANDS trial, the median duration of exposure was 42 weeks, with the median ADA sampling period of 27 weeks. In the MEDALIST trial, the median duration of exposure was 49 weeks, with the median ADA sampling period of 46 weeks. Of the 331 ESA-naïve (COMMANDS trial) and ESA-refractory or -intolerant (MEDALIST trial) patients with MDS who were treated with REBLOZYL, 21 patients (6.3%) tested positive for treatment-emergent antiÂluspatercept-aamt antibodies, including 14 patients (4.2%) who had neutralizing antibodies. The majority of anti-luspatercept-aamt antibodies were of low titers.
There were no severe acute systemic hypersensitivity reactions reported for patients with antiÂluspatercept-aamt antibodies in REBLOZYL clinical trials, and there was no association between hypersensitivity type reaction or injection site reaction and presence of anti-luspatercept-aamt antibodies. There was no apparent effect of anti-luspatercept-aamt antibodies on clinical response.
Anti-Drug Antibody Effects On Pharmacokinetics
Among patients in the BELIEVE trial with luspatercept-aamt exposure data available, luspatercept-aamt mean trough concentration (Ctrough) was approximately 35% lower in 4 patients with beta thalassemia who tested positive for treatment-emergent anti-luspatercept-aamt antibodies (2.19 μg/mL) compared to patients with beta thalassemia who did not develop treatment-emergent anti-luspatercept-aamt antibodies (3.38 μg/mL). There is insufficient data to assess whether the observed anti-luspatercept-aamt antibody associated pharmacokinetic changes reduce effectiveness in patients with beta thalassemia.
Among 21 ESA-naïve and ESA-refractory or -intolerant patients with MDS in the COMMANDS and MEDALIST trials who tested positive for treatment-emergent anti-luspatercept-aamt antibodies, there were no identified clinically significant effects of anti-luspatercept-aamt antibodies on pharmacokinetics, pharmacodynamics, safety, or effectiveness of luspatercept-aamt over the treatment duration.
Clinical Studies
Beta Thalassemia
The efficacy of REBLOZYL was evaluated in adult patients with beta thalassemia in the BELIEVE trial (NCT02604433). BELIEVE was a multicenter, randomized, double-blind, placebo-controlled trial in which (n=336) patients with beta thalassemia requiring regular red blood cell transfusions (6-20 RBC units per 24 weeks) with no transfusion-free period greater than 35 days during that period 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. All patients were eligible to receive best supportive care, which included RBC transfusions; iron-chelating agents; use of antibiotic, antiviral, and antifungal therapy; and/or nutritional support, as needed.
The BELIEVE trial excluded patients with a diagnosis of Hemoglobin S/β-thalassemia or isolated alpha (α)-thalassemia (e.g., Hemoglobin H) or who had major organ damage (liver disease, heart disease, lung disease, renal insufficiency). Patients with recent deep vein thrombosis or stroke or recent use of ESA, immunosuppressant, or hydroxyurea therapy were also excluded. The median age was 30 years (range: 18-66). The trial was comprised of patients who were 42% male, 54.2% White, 34.8% Asian, and 0.3% Black or African American. The percent of patients reporting their race as “other” was 7.7%, and race was not collected or reported for 3% of patients.
Table 12 summarizes the baseline disease-related characteristics in the BELIEVE study.
Table 12: Baseline Disease Characteristics of Patients with Beta Thalassemia in BELIEVE
| Disease Characteristic |
REBLOZYL
(N=224) |
Placebo
(N=112) |
| Beta thalassemia diagnosis, n (%) |
| Beta-thalassemia |
174 (77.7) |
83 (74.1) |
| HbE/beta thalassemia |
31 (13.8) |
21 (18.8) |
| Beta thalassemia combined with alpha-thalassemia |
18 (8) |
8 (7.1) |
| Missing a |
1 (0.4) |
0 |
| Baseline transfusion burden 12 weeks prior to randomization |
| Median (min, max) (Units/12 weeks) |
6.12 (3, 14) |
6.27 (3, 12) |
| Beta thalassemia gene mutation grouping, n (%) |
| β0/β0 |
68 (30.4) |
35 (31.3) |
| Non-β0/β0 |
155 (69.2) |
77 (68.8) |
| Missing a |
1 (0.4) |
0 |
| Baseline serum ferritin level (μg/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) |
| Age patient started regular transfusions (years) |
| N |
169 |
85 |
| Median (min, max) |
2 (0, 52) |
2 (0, 51) |
HbE=hemoglobin E.
a “Missing” category includes patients in the population who had no result for the parameter listed. |
The efficacy of REBLOZYL in adult patients with beta thalassemia was established based upon the proportion of patients achieving RBC transfusion burden reduction (≥33% reduction from baseline) with a reduction of at least 2 units from Week 13 to Week 24.
Efficacy results are shown in Table 13.
Table 13: Efficacy Results in Beta Thalassemia –BELIEVE
| Endpoint |
REBLOZYL
(N=224) |
Placebo
(N=112) |
Risk Difference (95% CI) |
p-value |
| ≥33% Reduction from baseline in RBC transfusion burden with a reduction of at least 2 units for 12 consecutive weeks |
| Primary endpoint - Week 13 to Week 24 |
47 (21.0) |
5 (4.5) |
16.5
(9.9, 23.1) |
<0.0001 |
| Week 37 to Week 48 |
44 (19.6) |
4 (3.6) |
16.1
(9.8, 22.4) |
<0.0001 |
| ≥50% Reduction from baseline in RBC transfusion burden with a reduction of at least 2 units for 12 consecutive weeks |
| Week 13 to Week 24 |
16 (7.1) |
2 (1.8) |
5.4
(1.2, 9.5) |
0.0402 |
| Week 37 to Week 48 |
23 (10.3) |
1 (0.9) |
9.4
(5, 13.7) |
0.0017 |
Treatment Of Myelodysplastic Syndromes With Associated Anemia In ESA-naïve Patients
The efficacy of REBLOZYL was evaluated in the COMMANDS trial (NCT03682536), a multi-center, open-label, randomized active-controlled trial comparing REBLOZYL versus epoetin alfa in patients with anemia due to IPSS-R very low, low, or intermediate-risk myelodysplastic syndromes or with myelodysplastic/myeloproliferative neoplasm with ring sideroblasts and thrombocytosis (MDS/MPN RS-T) in ESA-naïve patients (with endogenous sEPO levels of < 500 U/L) who require regular red blood cell transfusions. For eligibility, patients were required to have had 2 to 6 RBC units/8 weeks confirmed for a minimum of 8 weeks immediately preceding randomization.
The COMMANDS trial included 356 patients randomized 1:1 to REBLOZYL (N=178) or epoetin alfa (N=178). Randomization was stratified by RBC transfusion burden, RS status, and endogenous serum erythropoietin (sEPO) level at baseline. Treatment was started at 1 mg/kg subcutaneously every 3 weeks. Two dose level increases were allowed (to 1.33 mg/kg and to 1.75 mg/kg). Doses were held and subsequently reduced for adverse reactions, reduced if the hemoglobin increased by ≥ 2 g/dL from the prior cycle, and held if the predose hemoglobin was ≥ 12 g/dL.
All patients received best supportive care, which included RBC transfusions as needed. Patients were treated for 24 weeks and were assessed for efficacy at that time point. Treatment beyond 24 weeks was optional based upon response to treatment and absence of disease progression.
The median age of the 356 study participants was 74 years (range: 33, 93 years). The trial population was 56% male and 44% female; 79.5% were White, 0.6% Black or African American, 12.1% Asian, and race was not reported in 7.9% of patients. Ethnicities were reported as 85.4% for Not Hispanic or Latino patients, 6.5% for Hispanic or Latino patients, 7.6% for patients with no ethnicity reported, and 0.6% were unknown. IPSS-R risk classification at baseline was 9.3% very low, 72.2% low, 17.4% intermediate, 0.3% high, and 0.8% missing. Table 14 summarizes the baseline disease-related characteristics in the COMMANDS study.
Table 14: Baseline Disease Characteristics of Patients in COMMANDS
| Disease Characteristic |
REBLOZYL
(N=178) |
Epoetin Alfa
(N=178) |
| Hemoglobin (g/dL) - n (%) |
| Median (min, max) |
7.80 (4.7, 9.2) |
7.80 (4.5, 10.2) |
| Serum EPO (U/L) - n (%) |
| Median (min, max) |
78.7 (7.8, 495.8) |
85.9 (4.6, 462.5) |
| IPSS-R risk classification at baseline - n (%) |
| Very low |
16 (9.0) |
17 (9.6) |
| Low |
126 (70.8) |
131 (73.6) |
| Intermediate |
34 (19.1) |
28 (15.7) |
| High |
1 (0.6) |
0 (0) |
| Missing |
1 (0.6) |
2 (1.1) |
| Ring sideroblast status (per WHO criteria) - n (%) |
| RS+ |
130 (73.0) |
128 (71.9) |
| RS- |
48 (27.0) |
49 (27.5) |
| Missing |
0 (0) |
1 (0.6) |
| SF3B1 mutation status - n (%) |
| Mutated |
111 (62.4) |
99 (55.6) |
| Non-mutated |
65 (36.5) |
72 (40.4) |
| Missing |
2 (1.1) |
7 (3.9) |
The efficacy of REBLOZYL in the treatment of anemia in ESA-naïve adult patients with MDS was established at the time of the interim efficacy analysis based upon the proportion of patients who experienced both red blood cell transfusion independence (RBC-TI) [defined as the absence of any RBC transfusion during any consecutive 12-week period] and an associated concurrent mean improvement in hemoglobin by at least 1.5 g/dL for any consecutive 12 week period during Weeks 1-24.
At the time of the interim efficacy analysis, 301 subjects were included in the efficacy analysis, of which 147 were in the luspatercept arm and 154 were in the epoetin alfa arm, which is about 85% of the total information. The key efficacy results are shown in Table 15.
Table 15: Key Efficacy Results in COMMANDS
| Endpoint |
REBLOZYL
(N=147) |
Epoetin Alfa a
(N=154) |
| RBC-TI for ≥12 weeks with associated concurrent mean Hgb increase of ≥ 1.5 g/dL (Weeks 1-24) |
| Response rate, n (%) |
86 (58.5) |
48 (31.2) |
| (95% CI) |
(50.1, 66.6) |
(24.0, 39.1) |
| Common Rate Difference (95% CI) b |
26.6 (15.8, 37.4) |
| p-value c |
<0.0001 |
| Mean Hgb increase ≥ 1.5 g/dL (Weeks 1-24) |
| Response rate, n (%) |
106 (72.1) |
75 (48.7) |
| (95% CI) |
(64.1, 79.2) |
(40.6, 56.9) |
| Common Rate Difference (95% CI) b |
23.2 (12.2, 34.1) |
| HI-E per IWG ≥8 weeks (Weeks 1-24) |
| Response rate, n (%) |
109 (74.1) |
79 (51.3) |
| (95% CI) |
(66.3, 81.0) |
(43.1, 59.4) |
| Common Rate Difference (95% CI) b |
22.3 (11.8, 32.8) |
| p-value c |
<0.0001 |
| RBC-TI for 24 weeks (Weeks 1-24) |
| Response rate, n (%) |
70 (47.6) |
45 (29.2) |
| (95% CI) |
(39.3, 56.0) |
(22.2, 37.1) |
| Common Rate Difference (95% CI) b |
17.0 (6.7, 27.2) |
| p-value c |
0.0012 |
| RBC-TI for ≥12 weeks (Weeks 1-24) |
| Response rate, n (%) |
98 (66.7) |
71 (46.1) |
| (95% CI) |
(58.4, 74.2) |
(38.1, 54.3) |
| Common Rate Difference (95% CI) b |
19.1 (8.6, 29.6) |
| p-value c |
0.0003 |
EOT = End of treatment; HI-E = Hematologic Improvement – Erythroid Response; NE = Not Estimable; RBC-TI = red blood cell transfusion independence
a The majority of study participants (>90%) were outside of the United States and a non-U.S.-licensed epoetin alfa product was used in the control arm for such patients. Direct comparisons have not been established between REBLOZYL and U.S. licensed epoetin alfa product for the treatment of patients with anemia due to IPSS-R very low, low, or intermediate-risk myelodysplastic syndromes or MDS/MPN RS-T in ESA-naïve patients.
b Common rate difference is based on the Mantel-Haenszel stratum weights.
c Based on CMH test stratified by baseline RBC transfusion burden (< 4, ≥ 4 pRBC units), RS status (RS+, RS-) and sEPO level (≥ 200, > 200 U/L). 2-sided p-value is presented. The statistical significance level at the second interim analysis is two-sided p-value 0.03. |
No major outliers were observed in clinically relevant baseline demographic and disease characteristic subgroups.
Myelodysplastic Syndromes With Ring Sideroblasts Or Myelodysplastic/Myeloproliferative Neoplasm With Ring Sideroblasts And Thrombocytosis Associated Anemia In ESA-refractory Or -intolerant Patients
The efficacy of REBLOZYL was evaluated in the MEDALIST trial (NCT02631070), a multi-center, randomized, double-blind, placebo-controlled trial in patients with IPSS-R very low, low, or intermediate-risk myelodysplastic syndromes who have ring sideroblasts and require red blood cell transfusions (2 or more RBC units over 8 weeks). For eligibility, patients were required to have had an inadequate response to prior treatment with an erythropoiesis-stimulating agent (ESA), be intolerant of ESAs, or have a serum erythropoietin > 200 U/L. The MEDALIST trial excluded patients with deletion 5q (del 5q), white blood cell count > 13 Gi/L, neutrophils < 0.5 Gi/L, platelets < 50 Gi/L, or with prior use of a disease modifying agent for treatment of MDS.
The MEDALIST trial included 229 patients randomized 2:1 to REBLOZYL (n=153) or placebo (n=76). Randomization was stratified by baseline RBC transfusion burden and baseline IPSS-R. Treatment was started at 1 mg/kg subcutaneously every 3 weeks; the dose could be increased after completion of the first 2 cycles if the patient had at least one RBC transfusion in the prior 6 weeks. Two dose level increases were allowed (to 1.33 mg/kg and to 1.75 mg/kg). Doses were held and subsequently reduced for adverse reactions, reduced if the hemoglobin increased by ≥ 2 g/dL from the prior cycle, and held if the predose hemoglobin was ≥ 11.5 g/dL.
All patients received best supportive care, which included RBC transfusions as needed. The primary efficacy assessment was conducted after completion of 24 weeks on study drug. Patients with a decrease in transfusion requirement or increase in hemoglobin could continue on blinded study drug thereafter until unacceptable toxicity, loss of efficacy, or disease progression.
The median age of the 229 study participants was 71 years (range: 26, 95 years). The trial population was 63% male and 69% White. Table 16 summarizes the baseline disease-related characteristics in the MEDALIST study.
Table 16: Baseline Disease Characteristics of Patients in MEDALIST
| Disease Characteristic |
REBLOZYL
(N=153) |
Placebo
(N=76) |
| Time Since Original MDS Diagnosis a (months) |
| Median (range) |
44.0 (3, 421) |
36.1 (4, 193) |
| Serum EPO (U/L) Categories b, n (%) |
| < 200 |
88 (57.5) |
50 (65.8) |
| 200 to 500 |
43 (28.1) |
15 (19.7) |
| > 500 |
21 (13.7) |
11 (14.5) |
| Missing |
1 (0.7) |
0 |
| Diagnosis per WHO Criteria, n (%) |
| MDS-RS c |
135 (88.2) |
65 (85.5) |
| MDS/MPN-RS-T |
14 (9.2) |
9 (11.8) |
| Other d |
4 (2.6) |
2 (2.6) |
| IPSS-R Classification Risk Category, n (%) |
| Very low |
18 (11.8) |
6 (7.9) |
| Low |
109 (71.2) |
57 (75) |
| Intermediate |
25 (16.3) |
13 (17.1) |
| High |
1 (0.7) |
0 |
| RBC Transfusions/8 Weeks Over 16 Weeks Categories, n (%) |
| < 4 units |
46 (30.1) |
20 (26.3) |
| ≥ 4 and < 6 units |
41 (26.8) |
23 (30.3) |
| ≥ 6 units |
66 (43.1) |
33 (43.4) |
EPO=erythropoietin; IPSS R=International Prognostic Scoring System-Revised; ITT=intent-to-treat; MDS=myelodysplastic syndromes; RARS=refractory anemia with ring sideroblasts; RBC=red blood cell; RCMD=refractory cytopenia with multilineage dysplasia; SD=standard deviation; WHO=World Health Organization.
a Time since original MDS diagnosis was defined as the number of years from the date of original diagnosis to the date of informed consent.
b Baseline EPO was defined as the highest EPO value within 35 days of the first dose of study drug.
c Includes MDS-RS-MLD and MDS-RS-SLD. d Includes MDS-EB-1, MDS-EB-2, and MDS-U. |
The efficacy of REBLOZYL in adult patients with MDS-RS and MDS-RS-T was established based upon the proportion of patients who were red blood cell transfusion independent (RBC-TI), defined as the absence of any RBC transfusion during any consecutive 8-week period occurring entirely within Weeks 1 through 24.
The efficacy results are shown in Tables 17 and 18.
Table 17: Efficacy Results in MEDALIST
| Endpoint |
REBLOZYL
(N=153) n, % (95% CI) |
Placebo
(N=76) n, % (95% CI) |
Common Risk Difference (95% CI) |
p-value |
| RBC-TI ≥ 8 weeks during Weeks 1-24 |
58 (37.9) (30.2, 46.1) |
10 (13.2) (6.5, 22.9) |
24.6 (14.5, 34.6) |
<0.0001 |
| RBC-TI ≥ 12 weeks during Weeks 1-24 |
43 (28.1) (21.1, 35.9) |
6 (7.9) (3.0, 16.4) |
20.0 (10.9, 29.1) |
0.0002 |
| RBC-TI ≥ 12 weeks during Weeks 1-48* |
51 (33.3) (25.9, 41.4) |
9 (11.8) (5.6, 21.3) |
21.4 (11.2, 31.5) |
0.0003 |
| * The median (range) duration of treatment was 49 weeks (6 to 114 weeks) on the REBLOZYL arm and 24 weeks (7 to 89 weeks) on the placebo arm. |
Table 18 shows the proportion of patients who achieved RBC-TI ≥ 8 weeks during Weeks 1-24 by diagnosis and baseline transfusion requirement.
Table 18: RBC-TI ≥ 8 Weeks during Weeks 1-24 By Diagnosis and Baseline Transfusion Burden in MEDALIST
|
Responders/N |
% Response (95% CI) |
| REBLOZYL |
Placebo |
REBLOZYL |
Placebo |
| WHO 2016 Diagnosis |
| MDS-RS |
46 / 135 |
8 / 65 |
34.1
(26.1, 42.7) |
12.3
(5.5, 22.8) |
| MDS/MPN-RS-T |
9 / 14 |
2 / 9 |
64.3
(35.1, 87.2) |
22.2
(2.8, 60.0) |
| Other a |
3 / 4 |
0 / 2 |
75.0
(19.4, 99.4) |
0.0
(0.0, 84.2) |
| Baseline RBC Transfusion Burden |
| 2 - 3 units/8 weeks b |
37 / 46 |
8 / 20 |
80.4
(66.1, 90.6) |
40.0
(19.1, 63.9) |
| 4 - 5 units/8 weeks c |
15 / 41 |
1 / 23 |
36.6
(22.1, 53.1) |
4.3
(0.1, 21.9) |
| ≥ 6 units/8 weeks |
6 / 66 |
1 / 33 |
9.1
(3.4, 18.7) |
3.0
(0.1, 15.8) |
a Includes MDS-EB-1, MDS-EB-2, and MDS-U.
b Includes patients who received 3.5 units.
c Includes patients who received 5.5 units. |