Associations Between Platelet Count and Survival and Disease Progression In Thrombocytopenic Patients with Myelodysplastic Syndromes

Abstract Abstract 2905 Introduction: Myelodysplastic syndromes (MDS) are a group of malignant bone marrow stem cell disorders characterized by a predisposition for transformation to acute myelogeneous leukemia (AML). MDS disorders are heterogeneous in their morphology, cytogenetics, survival time, and ability to transform to AML. Although numerous classification schemes have been developed to provide a reproducible method for estimating patient survival and risk of leukemic evolution, research continues to identify factors that affect prognosis and survival time (e.g., treatment type, WHO FAB subgroups, karyotype, and transfusion status) and refine existing classification schemes. The goal of this analysis was to evaluate the effect of platelet counts on survival and disease progression to AML among thrombocytopenic (platelet count <100 × 109/L) MDS patients (n = 303) using the International MDS Risk Analysis Workshop (IMRAW) database. Methods: The IMRAW dataset includes demographic, clinical and prognostic information for patients treated in the United States, Europe, and Japan who were diagnosed with MDS between 1972 and 1994. Platelet count (× 109/L) was categorized as follows: 0 to <20, 20 to <30, 30 to <50, 50 to <70, 70 to <80, 80 to <90, 90 to <100, and ≥100. Survival was modeled using the Kaplan-Meier (K-M) estimator. One-, two-, and three-year survival rates and median, quartile, and restricted mean survival time were estimated using K-M methods. Time to evolution to AML was modeled using the Nelson-Aalen (N-A) cumulative hazard estimator with death prior to onset of AML as a competing risk event. One-, two-, and three-year cumulative rates of AML evolution were generated using N-A methods. Mean, median, and quartile values for time to AML evolution were also summarized. Cox proportional hazards modeling was used to estimate the hazard ratio (HR) for survival and evolution of MDS to AML. Results: Among thrombocytopenic MDS patients (n = 303), one-, two- and three-year survival were 58%, 44%, and 33%, respectively. Median survival was 19.6 months, with the lowest among those with a platelet count 0 to <20 × 109/L (10.9 months) and the highest among those with a platelet count 90 to <100 × 109/L (33.2 months). Patients with platelet counts (x 109/L) <70, 70 to <90, and ≥90 formed three distinct survival groups for approximately three years after MDS diagnosis (Figure 1). Across platelet categories, one-, two- and three-year survival ranged from 48.2% to 83.4%, 37.3% to 68.0%, and 30.5% to 39.9%, respectively (Table 1). Among non-thrombocytopenic MDS patients (platelet count ≥100 × 109/L), the one-, two- and three-year survival were 83.1%, 68.6%, and 59.1%, respectively, and the median survival was 47.3 months. Results of Cox models for thrombocytopenic MDS patients suggested an increased risk of death with platelet counts <90 × 109/L compared to platelet counts 90 to <100 × 109/L and no relationship was shown between strength of the HR and decreasing platelet count when adjusted for gender, age, year of diagnosis and institution (Table 1). Among thrombocytopenic MDS patients who developed AML (n = 73), median time to AML diagnosis from MDS diagnosis was 9.2 months. One-, two- and three-year evolution to AML rates were 21%, 30%, and 38%, respectively. Conclusions: Platelet count in thrombocytopenic MDS patients may be clinically relevant to survival and should be evaluated further. Platelet count does not appear to be associated with risk of evolution to AML. Evaluation of these relationships in a larger sample is warranted. Disclosures: Yong: Amgen Inc: Employment, Equity Ownership. Kuehn:Amgen Inc: Research Funding. Kelsh:Amgen Inc: Research Funding. Wagner:Amgen Inc: Research Funding. Yang:Amgen Inc: Employment, Equity Ownership. Franklin:Amgen Inc: Employment, Equity Ownership.

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Final Results of Open-Label Treatment with Eltrombopag During ENABLE 1: A Study of Eltrombopag As An Adjunct for Antiviral Treatment of Hepatitis C Virus Associated with Thrombocytopenia

Blood ◽

10.1182/blood.v118.21.2232.2232 ◽

2011 ◽

Vol 118 (21) ◽

pp. 2232-2232 ◽

Cited By ~ 3

Author(s):

Geoffrey Dusheiko ◽

Nezam H Afdhal ◽

Edoardo Giannini ◽

Pei-Jer Chen ◽

Kwang-Hyub Han ◽

...

Keyword(s):

Platelet Count ◽

Hepatitis C ◽

Research Funding ◽

Antiviral Treatment ◽

Treatment Phase ◽

Open Label ◽

Employment Equity ◽

Platelet Counts ◽

Equity Ownership

Abstract Abstract 2232 Introduction: Thrombocytopenia (TCP) is a common complication of cirrhosis in patients with hepatitis C virus (HCV) infections (Louie et al 2011); the presence of TCP impairs the ability to initiate peginterferon alpha (PEG) therapy and necessitates PEG dose reduction or discontinuation, thus reducing the potential for sustained virologic response (SVR). Eltrombopag, an oral, nonpeptide thrombopoietin receptor agonist approved for the treatment of chronic immune thrombocytopenia, increases platelet counts in patients with TCP due to HCV-related cirrhosis (McHutchison et al 2007). ENABLE 1 was a phase 3, multicenter, two-part study of eltrombopag for the treatment of HCV-associated TCP. Part 1 involved open-label, pre-antiviral treatment with eltrombopag. Patients achieving platelet counts ≥90,000/μL were randomized in Part 2 to receive eltrombopag or placebo in combination with antiviral therapy (PEG-2a plus ribavirin). Aim: To assess the safety and efficacy of eltrombopag during the open-label, pre-antiviral treatment phase (Part 1) of ENABLE 1 in patients with cirrhosis. Methods: Patients with chronic HCV and a baseline platelet count <75,000/μL were enrolled. In Part 1, all patients received open-label oral eltrombopag (25 mg daily with dose escalations every 2 weeks to a maximum dose of 100 mg) for up to 9 weeks or until platelet counts reached ≥90,000/μL. Patients who failed to achieve platelet counts ≥90,000/μL following 3 weeks of eltrombopag 100 mg daily did not enter Part 2 and attended scheduled follow-up visits. Patients achieving these counts were randomized 2:1 to eltrombopag or placebo (Part 2) at the final dose received in Part 1, in combination with antiviral therapy for up to 48 weeks. Results: A total of 716 patients were enrolled; 1 patient withdrew due to a protocol deviation, and 715 entered the open-label pre-antiviral phase. At study entry, most patients were male (62%) and Caucasian (72%); 17% were of Japanese/East Asian heritage. The median age was 52 years (range, 19–76). 488 patients (68%) had cirrhosis (FibroSURE™ score equivalent to METAVIR F4). The median duration of treatment during Part 1 was 20 days and the median of the mean daily dose was 25 mg (range, 0.8–75 mg). Median baseline platelets were 59,000/μL; these increased to 89,000/μL by week 2 and remained consistently elevated throughout open-label treatment (Figure). Following a median of 2 weeks of treatment (range, 0.1–9.6 weeks), 691 patients (97%) achieved platelet counts ≥90,000/μL. Treatment was discontinued during Part 1 for 33 patients (5%): platelets <90,000/μL (11); adverse events (AEs, 9); investigator discretion (7); patient decision (3); loss of follow-up (2); or a protocol deviation (1). During Part 2, 682 patients (95%) were randomized, 2 patients withdrew consent following randomization, and 680 patients (95%) initiated antiviral treatment. Of the patients who initiated treatment, 451 (66%) did so within 2 weeks and 627 (92%) did so within 4 weeks. The most common AEs observed during the open-label treatment phase were headache (7%), fatigue (4%), nausea (3%), and diarrhea (3%). Ninety-five patients (13%) experienced platelet counts >200,000/μL. No thromboembolic events were observed during open-label treatment. Conclusions: Eltrombopag was generally well-tolerated and resulted in sustained increase in platelet counts during the open-label, pre-antiviral treatment phase. Platelet count increases were seen as early as 2 weeks following initiation of treatment. The vast majority of patients (97%) achieved platelet count increases to ≥90,000/μL, the threshold for initiating PEG-2a plus ribavirin therapy, and most did so within 4 weeks of initiating eltrombopag treatment. Disclosures: Dusheiko: GlaxoSmithKline: Consultancy, Honoraria, Research Funding; Roche: Consultancy, Honoraria, Research Funding; Merck: Consultancy, Honoraria, Research Funding. Off Label Use: Eltrombopag, inteferon and Ribavirin; eltrombopag is a thrombopoetin receptor agonist. Its efficacy and safety in raising platelet counts in hepatitis C positive patients (most with cirrhosis) and thrombocyotopaenia was studied in this protocol. Afdhal:Merck: Consultancy, Honoraria, Research Funding; Vertex: Consultancy, Honoraria, Research Funding; Idenix: Consultancy, Honoraria, Research Funding; GlaxoSmithKline: Consultancy, Honoraria, Research Funding; Springbank: Consultancy, Honoraria, Research Funding; Gilead: Consultancy, Honoraria, Research Funding; Pharmasett: Consultancy, Honoraria, Research Funding; Abbott: Consultancy, Honoraria, Research Funding. Giannini:GlaxoSmithKline: Consultancy, Speakers Bureau; Hoffman-LaRoche: Consultancy, Speakers Bureau. Chen:Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Mostafa Kamel:GlaxoSmithKline: Employment, Equity Ownership. Brainsky:GlaxoSmithKline: Employment, Equity Ownership. Geib:GlaxoSmithKline: Employment. Vasey:GlaxoSmithKline: Employment. Patwardhan:GlaxoSmithKline: Employment, company shares. Campbell:GlaxoSmithKline: Employment, Equity Ownership. Theodore:GlaxoSmithKline: Employment, Equity Ownership, Patents & Royalties.

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Final Results from an International, Multi-Center, Single-Arm Study Evaluating the Safety and Efficacy of Romiplostim in Adults with Primary Immune Thrombocytopenia (ITP),

Blood ◽

10.1182/blood.v118.21.3279.3279 ◽

2011 ◽

Vol 118 (21) ◽

pp. 3279-3279 ◽

Cited By ~ 6

Author(s):

Ann Janssens ◽

Michael D. Tarantino ◽

Robert Bird ◽

Maria Gabriella Mazzucconi ◽

Ralph Vincent V. Boccia ◽

...

Keyword(s):

Bone Marrow ◽

Platelet Count ◽

Board Of Directors ◽

Research Funding ◽

Platelet Response ◽

Employment Equity ◽

Advisory Committees ◽

Platelet Production ◽

Platelet Counts ◽

Equity Ownership

Abstract Abstract 3279 Background: ITP is an autoimmune disorder characterized by increased platelet destruction and suboptimal platelet production. Romiplostim stimulates platelet production via the TPO-receptor, and is recommended for second- and third-line treatment of chronic ITP in adults. We report final data from a large prospective study of romiplostim in adults with ITP of varying duration and severity. Methods: Eligibility criteria were broad: patients ≥18 years of age, who had received prior ITP therapies (final protocol amendment: ≥1, previous amendments: ≥3), with low platelet counts (final amendment: ≤ 30 × 109/L, previous amendments: ≤ 10, ≤ 20 × 109/L) or experiencing uncontrolled bleeding. The only excluded comorbidities were: hematological malignancy, myeloproliferative neoplasms, MDS and bone marrow stem cell disorder. Romiplostim was initiated at 1 (final amendment) or 3 (previous amendments) μg/kg/week, with dose adjustments allowed to maintain platelet counts ≥50 × 109/L. Patients could continue on study until they had access to commercially available romiplostim. Rescue medications were allowed at any time; concurrent ITP therapies could be reduced when platelet counts were > 50 × 109/L. Primary endpoint was incidence of adverse events (AEs) and antibody formation. Secondary endpoint was platelet response, defined as either (1) doubling of baseline count and ≥ 50 × 109/L or (2) ≥20 × 109/L increase from baseline. Results: A total of 407 patients received romiplostim, 60% of whom were female. Median (Q1, Q3) time since ITP diagnosis was 4.25 (1.20, 11.40) years (maximum 57.1 years), with 51% of patients splenectomised and 39% receiving baseline concurrent ITP therapies. Seventy-one percent of patients completed the study, with requirement for alternative therapy and withdrawn consent the most common reasons for discontinuation (5% each). Median (Q1, Q3) on-study treatment duration was 44.29 (20.43, 65.86) weeks (maximum 201 weeks), with a total of 20,201 subject-weeks on study. Incidence and type of AEs were consistent with previous studies. The most common serious treatment-related AEs were cerebrovascular accident, headache, bone marrow reticulin fibrosis (with no evidence of positive trichrome staining for collagen and no evidence suggesting primary idiopathic myelofibrosis), nausea, deep vein thrombosis, hemorrhage and pulmonary embolism, with each reported in 2 of 407 (0.5%) patients. All other serious treatment-related AEs were each reported in one patient. Eighteen patients died; 3 deaths (hemolysis, intestinal ischaema, aplastic anemia) were considered treatment-related. No neutralizing antibodies to romiplostim or TPO were reported. Approximately 90% of patients achieved each of the platelet response definitions, regardless of splenectomy status. Overall, median (Q1, Q3) time to response was 2 (1, 4) weeks for response definition 1, and 1 (1, 3) week for response definition 2. Median (Q1, Q3) baseline platelet count was 14 (8, 21) × 109/L. After 1 week of treatment median (Q1, Q3) platelet count had increased to 42 (18, 101) × 109/L. From week 8 onwards, and excluding counts within 8 weeks of rescue medication use, median platelet counts were consistently above 100 × 109/L (range 101.0–269.5 × 109/L). Median (Q1, Q3) average weekly romiplostim dose was 3.62 (1.99, 6.08) μg/kg. Summary/conclusions: This is the largest prospective study in adult ITP reported to date. The data reported here are similar to those reported for previous romiplostim studies, with romiplostim able to safely induce a rapid platelet response in adult ITP patients with low platelet counts or bleeding symptoms. Romiplostim is an important, well-tolerated, treatment option for adult ITP patients, which significantly increases and maintains platelet counts. Adverse Event Subject Incidence Platelet Response Disclosures: Janssens: Amgen: Consultancy; Roche: Speakers Bureau; GSK: Membership on an entity's Board of Directors or advisory committees. Tarantino:Cangene corporation: Research Funding; Baxter: Research Funding; Talecris: Honoraria, Speakers Bureau; Up-to-date: Patents & Royalties; The Bleeding and Clotting Disorders Institute: Board Member. Bird:Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; GSK: Membership on an entity's Board of Directors or advisory committees. Boccia:Amgen: Equity Ownership, Honoraria, Speakers Bureau. Lopez-Fernandez:Amgen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Kozak:Amgen: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees. Steurer:Amgen: Honoraria. Dillingham:Amgen Limited: Employment, Equity Ownership. Lizambri:Amgen: Employment, Equity Ownership.

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PETIT and PETIT 2: Treatment with Eltrombopag in 171 Children with Chronic Immune Thrombocytopenia (ITP)

Blood ◽

10.1182/blood.v124.21.1450.1450 ◽

2014 ◽

Vol 124 (21) ◽

pp. 1450-1450 ◽

Cited By ~ 1

Author(s):

James B. Bussel ◽

John D. Grainger ◽

Purificacion Garcia de Miguel ◽

Jenny M. Despotovic ◽

Franco Locatelli ◽

...

Keyword(s):

Platelet Count ◽

Board Of Directors ◽

Research Funding ◽

Employment Equity ◽

Advisory Committees ◽

Platelet Counts ◽

Chronic Itp ◽

Thrombopoietin Receptor ◽

Count Response ◽

Equity Ownership

Abstract Background: Eltrombopag (EPAG), an oral thrombopoietin receptor agonist, is approved for treating thrombocytopenia in adults with chronic immune thrombocytopenia (ITP) with insufficient response to prior therapy. Pooled data from 2 similarly designed, randomized, double-blind, placebo (PBO)-controlled studies investigating safety and efficacy of EPAG in pediatric ITP are presented here. Methods: Subjects aged 1 to <18 years with a confirmed diagnosis of persistent or chronic ITP and a platelet count <30 Gi/L at day 1 were randomized 2:1 to EPAG or PBO and stratified by age: 12–17 years (Cohort 1), 6–11 years (Cohort 2), and 1–5 years (Cohort 3). Subjects could continue baseline ITP medications. After the PBO-controlled randomized phase, subjects were permitted to complete 17 or 24 weeks of treatment with open-label (OL) EPAG. Dose was adjusted based on platelet counts to a maximum of 75 mg daily. Results: A total of 174 subjects were enrolled in both studies; 171 received ≥1 dose of EPAG. 159 subjects were randomized (intent-to-treat population), and 157 received ≥1 dose of randomized study treatment (safety population). In the randomized period, 3 EPAG and 1 PBO subject discontinued study treatment, of which 2 EPAG and 1 PBO discontinued due to adverse events (AEs). In the OL-EPAG period, an additional 14 EPAG subjects discontinued study treatment, 6 due to AEs. Males comprised 47% of the EPAG and PBO groups and 20% and 24% were East Asians, respectively. Most subjects (93%) were diagnosed with ITP for ≥12 months, and 13% were receiving ITP medications at baseline. The majority of subjects (81%) received ≥2 prior ITP therapies. Most subjects (59%) had a baseline platelet count <15 Gi/L. All 9 (6%) splenectomized subjects were randomized to the EPAG group. Randomized Period A higher proportion of EPAG versus PBO subjects (62% vs 24%; P < 0.001) achieved a response with platelet counts ≥50 Gi/L at least once between weeks 1–6 (Cohort 1, 64% vs 11%; Cohort 2, 64% vs 27%; Cohort 3, 54% vs 36%, respectively). At each week, a higher proportion of EPAG subjects had a response versus PBO (Fig. 1). A lower proportion of EPAG subjects (13%) received rescue treatment compared with PBO subjects (31%; P = 0.009). The odds of having World Health Organization (WHO) bleeding grades 1–4 (0.19; P = 0.011) and clinically significant (WHO grades 2–4) bleeding (0.29; P = 0.007) were lower for EPAG versus PBO subjects. EPAG-Only Period Sustained reduction or discontinuation of baseline ITP medications, primarily corticosteroids, was achieved by 50% of subjects; 81% of subjects had a platelet count response at least once; 52% (n = 80/154) had a platelet count response for ≥50% of assessments; and 38% (n = 58/154) responded for ≥75% of assessments. For >13 of 24 weeks, 47% of subjects achieved responses (Fig. 2). The median average daily dose for EPAG-exposed patients in Cohorts 1, 2, and 3 were 64.0 mg (0.93 mg/kg), 57.6 mg (1.50 mg/kg), and 37.0 mg (2.02 mg/kg), respectively. AEs Similar proportions of subjects in the EPAG and PBO groups reported an AE during the randomization period. The most common AEs (≥10% of subjects) were headache, upper respiratory tract infection, and nasopharyngitis in the EPAG group, and headache, epistaxis, and vomiting in the PBO group. Serious AEs (SAEs) were reported in 8% of EPAG subjects versus 12% of PBO subjects. No SAEs were reported by >1 subject in either treatment group except epistaxis, which was reported by 2 subjects in the PBO group. No SAEs were common to both treatment groups. In the randomized period, an ALT elevation of ³3 x ULN occurred in 5 (4.7%) subjects in the EPAG group and no subjects in the PBO group. In the OL period, there were an additional 7 subjects with ALT ³3 x ULN. All elevations resolved either while still on treatment or after discontinuation of study treatment. Overall, the hepatobiliary laboratory findings were mostly mild, reversible, and not accompanied by impaired liver function. Fewer EPAG than PBO subjects reported bleeding AEs (17% vs 36%, respectively). No thromboembolic events were reported. Cataract events were experienced by 2 subjects who received EPAG; both had used corticosteroids and 1 had pre-existing cataracts. Conclusions: EPAG was safe and raised platelet counts in 62% of pediatric patients with persistent and chronic ITP during the randomized phase. Treatment with EPAG was well tolerated in both studies as evidenced by the low incidence of treatment discontinuations due to AEs. Disclosures Bussel: Shionogi: Membership on an entity's Board of Directors or advisory committees, Research Funding; Rigel: Honoraria; Novartis: Honoraria; Ligand: Membership on an entity's Board of Directors or advisory committees, Research Funding; Immunomedics: Research Funding; IgG of America: Research Funding; GlaxoSmithKline: Equity Ownership, Honoraria, Research Funding; Genzyme: Research Funding; Eisai, Inc.: Research Funding; Cangene: Honoraria, Research Funding; Bristol-Myers Squibb: Honoraria; Amgen: Equity Ownership, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Symphogen: Membership on an entity's Board of Directors or advisory committees; Sysmex: Research Funding. Off Label Use: Eltrombopag is a thrombopoietin receptor agonist approved for the treatment of thrombocytopenia in adults with chronic ITP. Use in children and adolescents will be discussed.. Grainger:GlaxoSmithKline: Honoraria; Baxter: Honoraria, Research Funding; Amgen: Honoraria. Pongtanakul:GlaxoSmithKline: Research Funding. Komvilaisak:GlaxoSmithKline: I am an investigator on this study. Other. Sosothikul:CSL Behring: Research Funding; GlaxoSmithKline: Research Funding. Drelichman:GlaxoSmithKline: I am investigator on this study. Other. David:GlaxoSmithKline: Research Funding. Marcello:GlaxoSmithKline: Employment. Iyengar:GlaxoSmithKline: Employment. Chan:GlaxoSmithKline: Employment. Chagin:GlaxoSmithKline: Employment. Theodore:GlaxoSmithKline: Employment, Equity Ownership. Bakshi:GlaxoSmithKline: Employment, Equity Ownership. Bailey:GlaxoSmithKline: Employment, Equity Ownership.

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A Randomized, Double-Blind, Placebo-Controlled Phase 1/2 Study to Determine the Safety and Efficacy of Romiplostim in Children with Chronic Immune (Idiopathic) Thrombocytopenic Purpura (ITP).

Blood ◽

10.1182/blood.v114.22.680.680 ◽

2009 ◽

Vol 114 (22) ◽

pp. 680-680 ◽

Cited By ~ 1

Author(s):

George R. Buchanan ◽

Lisa Bomgaars ◽

James B. Bussel ◽

Diane J. Nugent ◽

David J. Gnarra ◽

...

Keyword(s):

Platelet Count ◽

Board Of Directors ◽

Treatment Period ◽

Research Funding ◽

Bleeding Events ◽

Employment Equity ◽

Advisory Committees ◽

Platelet Counts ◽

Chronic Itp ◽

Equity Ownership

Abstract Abstract 680 Introduction: ITP is an autoimmune disorder characterized by thrombocytopenia due to accelerated destruction as well as suboptimal platelet production. Childhood ITP is most commonly an acute illness; however, chronic ITP (duration > 6 months) develops in 20%–30% of ITP cases. Romiplostim, a peptibody protein designed to increase platelet production, is approved for treating chronic ITP in adults. The objective of this study was to evaluate the safety and efficacy of romiplostim in the treatment of thrombocytopenia in children with chronic ITP. Patients and Methods: ITP patients aged 12 months to <18 years with persistent severe thrombocytopenia for at least six months before enrollment (mean of 2 platelet counts ≥ 30 × 109/L at baseline) were included in this study. Patients were randomized (3:1) to receive romiplostim or placebo and stratified by age: 12 months - <3 years (N=4), 3 - <12 years (N=8), and 12 - <18 years (N=8). Treatment for a 12 week period was followed by a 4 week pharmacokinetic (PK) assessment period for responding patients (those who achieved a platelet count of >20 × 109/L above baseline for 2 consecutive weeks without rescue therapy at any point during the treatment period). Treatment was initiated at 1 μg/kg once weekly by subcutaneous injection. The dose was adjusted in 2 μg/kg increments every two weeks, to a maximum dose of 10 μg/kg/week based on weekly platelet counts. The incidence of adverse events (AEs) during the 12-week treatment period and the number of patients achieving platelet counts >50 × 109/L for 2 consecutive weeks during the treatment period, or achieving an increase in platelet count >20 × 109/L above baseline for 2 consecutive weeks during the treatment period was recorded. Results: A total of 22 (romiplostim, 17; placebo, 5) patients were randomized; 16 (73%) were boys and 6 (27%) were girls. Eight patients had undergone splenectomy. The mean age was 9.5 (SD: 5.1) years, with 4 subjects aged 12 months - <3 years, 10 aged 3 - <12 years, and 8 aged 12 - <18 years. The median baseline platelet count was 13 × 109/L (range 2 to 29 × 109/L) and the median duration of ITP was 2.4 years (range 0.6 to 14 years). All patients completed the study. Sixteen of 17 patients in the romiplostim arm (94%) and 5/5 in the placebo arm (100%) had at least 1 AE during the treatment period. The most common AEs were (romiplostim, placebo, respectively) headache (35%, 40%), epistaxis (35%, 20%), cough (12%, 40%), and vomiting (12%, 40%). Serious AEs were experienced by 1 patient in the romiplostim arm (moderate influenza and sepsis) and none in the placebo arm. AEs considered to be treatment related were reported for 3 (18%) and 1 (20%) subjects in the romiplostim and placebo arms, respectively; none of the treatment-related AEs were serious or of ≥3 grade severity. No patients died during the study and none tested positive for neutralizing antibodies to romiplostim or thrombopoietin. The same group of patients in the romiplostim-treated arm (15/17, 88.2%, 95% CI: 63.6%, 98.5%) achieved both efficacy endpoints during the treatment period. The median platelet count in the romiplostim-treated arm after 6 weeks of treatment was ≥50 × 109/L. The median weekly platelet count in the placebo arm remained stable at approximately 10 × 109/L. None of the placebo-treated patients achieved either platelet count endpoint. Rescue medication was administered to 2/17 (12%) of romiplostim- and 2/5 (40%) of placebo-treated patients during the 12 week treatment period. Twelve (71%) and 2 (40%) subjects in the romiplostim and placebo arms, respectively, experienced bleeding events. The majority of bleeding events (15/17) in the romiplostim arm occurred in the first 6 weeks of treatment. Most bleeding events (14/17) in the romiplostim arm and all bleeding events in the placebo arm occurred when the platelet count was < 30 × 109/L. A total of 14 patients treated with romiplostim entered the PK assessment period. The romiplostim serum concentration results were not different among the 3 age cohorts. The mean weekly dose of romiplostim in the treatment period was 3.4 (SD: 1.6) μg/kg. Conclusion: Treatment with romiplostim appeared to be well tolerated in pediatric ITP patients, with no new safety concerns observed in this study as compared to adults with chronic ITP. Romiplostim was effective in treating thrombocytopenia in children with chronic ITP. Disclosures: Buchanan: Amgen Inc.: Research Funding. Off Label Use: Use of romiplostim, a thrombopoietin mimetic, in treatment of thrombocytopenia in pediatric ITP patients. . Bomgaars:Novartis: Research Funding. Bussel:Eisai, Inc: Research Funding; Sysmex: Research Funding; Shionogi: Membership on an entity's Board of Directors or advisory committees; Ligand: Membership on an entity's Board of Directors or advisory committees, Research Funding; Immunomedics: Research Funding; Amgen: Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Research Funding; GlaxoSmithKline: Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Research Funding; Cangene: Research Funding; Genzyme: Research Funding; Scienta: Speakers Bureau. Nie:Amgen Inc.: Employment, Equity Ownership. Eisen:Amgen Inc.: Employment, Equity Ownership. Berger:Amgen Inc.: Employment, Equity Ownership.

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Predictors of Remission in Adults with Immune Thrombocytopenia Treated with Romiplostim

Blood ◽

10.1182/blood-2018-99-109791 ◽

2018 ◽

Vol 132 (Supplement 1) ◽

pp. 735-735

Author(s):

Adrian Newland ◽

James B. Bussel ◽

Robert Bird ◽

Donald M. Arnold ◽

Craig M. Kessler ◽

...

Keyword(s):

Multivariate Analysis ◽

Platelet Count ◽

Board Of Directors ◽

Research Funding ◽

Univariate Analysis ◽

Newly Diagnosed ◽

Employment Equity ◽

Advisory Committees ◽

Platelet Counts ◽

Equity Ownership

Abstract Background: In adults with ITP, thrombopoietin receptor agonists (TPO-RA) are often assumed to be lifelong therapy. However, some patients achieve treatment-free remission (TFR) by maintaining hemostatic platelet counts after discontinuing TPO-RA, despite not replacing them with other ITP medications. Predictors of safely discontinuing romiplostim have varied across studies. In an analysis of 8 romiplostim studies, 27 patients achieved TFR; more remitters than nonremitters had ITP for <12 months but there were no unequivocal predictors of TFR (Bussel et. al. Hematology 2016;21:257). In a phase 2 study with forced romiplostim taper after 12 months, 24 (32%) of 75 patients achieved TFR; a higher platelet count in the first 2 months was associated with TFR (P<.05; Newland et. al. Br J Haematol 2016;172:262). Differences between remitters and nonremitters for baseline patient characteristics and time to first platelet response were not statistically significant. Analysis of romiplostim treatment at 2 centers found that 12 (28%) of 43 patients achieved TFR; splenectomized patients were more likely than nonsplenectomized patients to achieve TFR (P=.05; Marshall et. al. Haematologica 2016;101:e476). Aim: This multivariate analysis integrated data across multiple romiplostim studies in adults with ITP to explore predictors of TFR. Methods: Data were pooled for 911 romiplostim-treated patients in 13 ITP studies conducted from 2002 to 2014. All patients failed first-line treatments before study enrollment. Secondary thrombocytopenia patients were excluded. Romiplostim treatment was discontinued per dosing rules; 1 study included a forced taper after 1 year of romiplostim. Typically, the romiplostim dose was reduced for platelet counts >200×109/L and withheld, then reduced, for platelet counts >400×109/L. Concomitant ITP medication could be reduced for platelet counts >50×109/L. TFR was defined as a ≥6-month treatment-free period with platelet counts consistently ≥50×109/L. Univariate analysis with logistic regression examined potential predictors of TFR, including age, sex, ITP duration, prior splenectomy, platelet count (baseline and first 4 weeks), bleeding in the first 6 months, and baseline concurrent therapy. Multivariate analysis with logistic regression evaluated significant predictors from the univariate analysis. Results: TFR was achieved by 61 ITP study patients who received romiplostim. For remitters vs nonremitters, median baseline age was 53 years in both cohorts; 57% vs 61% were female; and 93% vs 88% were Caucasian (Table 1). Median ITP duration at study baseline was 0.5 years among remitters and 3.5 years among nonremitters. Prior splenectomy occurred in 21% of remitters and 36% of nonremitters. The number of prior ITP treatments was ≤3 for 74% of remitters and 39% of nonremitters. Baseline platelet count was <30×109/L for 80% of remitters and 78% of nonremitters. Median platelet counts on treatment during the romiplostim studies were often higher among remitters than nonremitters, despite increasing median doses of romiplostim over time for nonremitters (Figure). During the first 6 months on study, 30% of remitters and 43% of nonremitters had a bleeding event. Prior splenectomy and bleeding in the first 6 study months were significant predictors of lower odds of TFR in the univariate model but not in the multivariate model. In the multivariate model, shorter ITP duration predicted significantly higher odds of TFR, either <3 months (newly diagnosed) vs >12 months (chronic; odds ratio [OR], 4.275; P<.0001) or 3-12 months (persistent) vs chronic (OR, 2.171; P=.0408; Table 2). One limitation of this analysis was 19 of 61 patients entering TFR were from one study of newly diagnosed and persistent patients; the protocol included a forced romiplostim taper. Number of previous treatments was not included in the multivariate analysis. Conclusions: In this integrated analysis of 911 adult ITP patients across 13 studies, shorter ITP duration at baseline (≤12 months) was an independent predictor of TFR. Neither previous splenectomy (which predicted TFR in 1 study) nor bleeding were independent predictors of TFR in this much larger analysis. In total, these results imply that earlier use of romiplostim in adults with ITP could be associated with greater likelihood of achieving TFR. Future studies should also explore biologic variables as predictors of TFR. Disclosures Newland: Amgen Inc., Angle, Dova Pharmaceuticals, Argenx, Rigel, Shionogi, Novartis: Consultancy; Amgen Inc., GlaxoSmithKline, and Novartis: Research Funding; Novartis: Speakers Bureau. Bussel:Uptodate: Honoraria; Protalex: Consultancy; Momenta: Consultancy; Rigel: Consultancy, Research Funding; Prophylix: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Amgen Inc.: Consultancy, Research Funding. Bird:Amgen, Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Arnold:Novartis: Consultancy, Research Funding; UCB: Consultancy; UCB: Consultancy; Bristol Myers Squibb: Research Funding; Amgen: Consultancy, Research Funding; Bristol Myers Squibb: Research Funding; Amgen: Consultancy, Research Funding; Novartis: Consultancy, Research Funding. Kessler:Novo Nordisk: Honoraria, Research Funding; Biomarin: Research Funding; Genentech: Research Funding; Dimension Advisory boards: Membership on an entity's Board of Directors or advisory committees; DSMB: Membership on an entity's Board of Directors or advisory committees; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sangamo: Research Funding; Bayer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Octapharma: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Mayer:Novartis: Research Funding; Amgen: Research Funding. Janssens:Roche: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Ad board, Speakers Bureau; Novartis: Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Speakers Bureau; Sanofi-Genzyme: Speakers Bureau; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Ad board, Speakers Bureau; Janssen: Consultancy, Speakers Bureau. Wang:Amgen: Employment, Equity Ownership. Eisen:Amgen Inc.: Employment, Equity Ownership.

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Cumulative Response to Eltrombopag and Impact of the Number of Prior ITP Therapies: Interim Results of a Long-Term Extension Study,

Blood ◽

10.1182/blood.v118.21.3297.3297 ◽

2011 ◽

Vol 118 (21) ◽

pp. 3297-3297

Author(s):

James B Bussel ◽

Christine K Bailey ◽

Andres Brainsky

Keyword(s):

Platelet Count ◽

Board Of Directors ◽

Research Funding ◽

Employment Equity ◽

Phase 3 ◽

Advisory Committees ◽

Platelet Counts ◽

Chronic Itp ◽

Equity Ownership

Abstract Abstract 3297 Background: Patients with chronic immune thrombocytopenia (ITP) have an increased risk of bleeding, ranging from minor to life-threatening. The goal of treatment is to increase and maintain platelets in a safe range to prevent bleeding. Guidelines state that achieving platelet counts of 30,000/μL to 50,000/μL in patients without other risk factors avoids the most serious complications of ITP, namely intra-cerebral or gastrointestinal hemorrhage (George 1996; Provan 2010). Many patients are refractory or relapse after multiple treatments. Eltrombopag is an oral, nonpeptide thrombopoietin receptor agonist approved for the treatment of chronic ITP. In 6-week, and 6-month, placebo-controlled trials in patients with heavily pre-treated chronic ITP, eltrombopag increased platelets and reduced bleeding and the need for concomitant ITP therapy (Bussel 2007; Bussel 2009; Cheng 2011). Long-term treatment with eltrombopag is being evaluated in EXTEND, an extension study in chronic ITP patients who completed a previous eltrombopag study (Saleh 2010). Aims: To analyze in EXTEND the ability of eltrombopag to increase platelet counts to ≥50,000/μL in >50% and >75% of assessments and to determine whether the number of prior ITP therapies influences this ability. Methods: Patients in EXTEND received eltrombopag or placebo in 1 of the following prior studies of eltrombopag in chronic ITP: a 6-week phase 2 (TRA100773A; Bussel 2007) or phase 3 (TRA100773B; Bussel 2009) study, a 6-month phase 3 study (RAISE; Cheng 2011), or a phase 3 study of intermittent treatment (REPEAT; Psaila 2008). Dosing in EXTEND is individualized in order to maintain platelet counts ≥50,000/μL and <200,000/μL while minimizing the use of concomitant ITP medications. For the purpose of this analysis, response is defined as a platelet count ≥50,000/μL. Results: Among the 299 patients enrolled in EXTEND between June 2006 and February 2010, 67 (22%), 73 (24%), 47 (16%), and 112 (37%) patients had received 1, 2, 3, and ≥4 prior therapies (excluding eltrombopag). The most commonly used prior therapies were corticosteroids (81%), IVIg (45%), splenectomy (38%), and rituximab (23%). Of the 299 patients enrolled, 70% achieved response in >50% of study assessments and 46% achieved response in >75% of assessments. Among 210 patients treated ≥12 months, 79% achieved response in >50% of assessments and 56% in >75% of assessments. Among 138 patients treated for ≥24 months, 82% achieved response in >50% and 59% in >75% of assessments. Response in >50% and >75% of assessments by the number of prior therapies was similar between the groups (Figure 1). The proportion of patients who achieved a response in >50% of assessments was similar between splenectomized and non-splenectomized patients (65% and 73%, respectively). Conclusion: The majority of patients treated with eltrombopag for ≥12 months achieved a platelet count of ≥50,000/μL in >50% of study assessments. This response was observed even among patients previously treated with 4 or more ITP therapies, suggesting that eltrombopag may be a viable treatment option even for more refractory chronic ITP patients. Disclosures: Bussel: Portola: Consultancy; Eisai: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; GlaxoSmithKline: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Amgen: Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Cangene: Research Funding; Genzyme: Research Funding; Immunomedics: Research Funding; Ligand: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Shionogi: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Sysmex: Research Funding. Bailey:GlaxoSmithKline: Employment, Equity Ownership. Brainsky:GlaxoSmithKline: Employment, Equity Ownership.

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Efficacy, Hematologic Effects, and Dose of Ruxolitinib in Myelofibrosis Patients with Low Starting Platelet Counts (50–100 × 109/L): A Comparison to Patients with Normal or High Starting Platelet Counts

Blood ◽

10.1182/blood.v120.21.176.176 ◽

2012 ◽

Vol 120 (21) ◽

pp. 176-176 ◽

Cited By ~ 4

Author(s):

Moshe Talpaz ◽

Ronald Paquette ◽

Lawrence Afrin ◽

Solomon Hamburg ◽

Katarzyna Jamieson ◽

...

Keyword(s):

Platelet Count ◽

Board Of Directors ◽

Research Funding ◽

Phase Iii ◽

Spleen Volume ◽

Employment Equity ◽

Advisory Committees ◽

Platelet Counts ◽

Equity Ownership ◽

Eortc Qlq

Abstract Abstract 176 Background: Ruxolitinib (RUX) has demonstrated clinical benefit for patients with myelofibrosis (MF) with or without the JAK2V617F mutation at starting doses of 15 or 20 mg PO BID by alleviating symptoms, improving quality of life measures, reducing spleen volume and exhibiting an apparent increase in overall survival in the phase III placebo (PBO)-controlled COMFORT-I study. Reversible declines in platelet count and hemoglobin (Hgb) can occur with ruxolitinib but are rarely treatment-limiting. Patients with MF who have low platelet counts represent an important subset of MF patients; given the potential risk of bleeding complications, a dosing strategy for such patients is needed. We assessed an alternative strategy using lower starting doses of ruxolitinib with subsequent dose escalation in patients with MF who have platelet counts of 50–100 × 109/L (Study INCB018424-258; NCT01348490). Methods: RUX dosing started at 5 mg BID. With adequate platelet count, doses could increase by 5 mg once daily every 4 weeks to 10 mg BID. Further increases required evidence of suboptimal efficacy. Assessments include measurement of MF symptoms (MF Symptom Assessment Form v2.0 Total Symptom Score [TSS]); Patient Global Impression of Change (PGIC); EORTC QLQ-C30, measurement of spleen volume by MRI, and safety/tolerability. Results: A total of 50 patients have enrolled, with data available for 41 patients. Nineteen have completed 24 weeks of treatment; >70% of these patients attained a final dose of ≥10 mg BID of RUX. Treatment was generally well tolerated in this study population with no withdrawals for thrombocytopenia or bleeding events. Based on analysis of adverse events, no new safety signals were observed in this population of MF patients with low platelet counts. Data for efficacy parameters, including spleen volume reduction, TSS reduction, and improvement in EORTC-QLQ-C30 subscales and PGIC were consistent with RUX treatment in the COMFORT-I study, and demonstrated clinically meaningful efficacy compared with the COMFORT-I PBO arm (Table). Of 19 patients with platelet count data through Week 24, 5 showed increased platelet count over the duration of the study (range of increase: 20 to 95 x109/L); all 5 patients had optimized dosing to ≥10 mg BID. Compared with the 14 patients showing smaller increases or modest decreases in platelet count, these 5 patients were younger (mean age: 63 years vs. 71 years), had been diagnosed with MF more recently (2.2 years vs. 5.2 years) and had lower DIPSS scores (60% Intermediate-1; 20% Intermediate-2; 20% High vs. 0% Intermediate-1; 79% Intermediate-2; 21% High). Four patients (9.8%) reported adverse events of bleeding (excluding events related to bruising) of any grade (all events were Grade 1 except one Grade 2 hematochezia), consistent with previously reported hemorrhage frequency in the COMFORT-I study (16.8%, RUX; 12.6%, PBO). Conclusions: These preliminary findings suggest that a dosing strategy of a low starting dose of RUX with escalation to 10 mg BID may be appropriate in MF patients who have low platelet counts. Most patients were able to titrate to a dose of ≥10 mg BID of RUX, a dose showing efficacy for both spleen volume and patient-reported outcomes generally consistent with previously reported data from Phase III trials. An increase in platelet counts was observed in approximately one-fourth of patients who completed 24 weeks of RUX treatment. Escalation to, and subsequent maintenance of, a 10 mg BID dose of RUX also preserves both Hgb and platelet count which may be beneficial for MF patients with anemia or thrombocytopenia. Disclosures: Talpaz: Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; BMS: Membership on an entity's Board of Directors or advisory committees, Research Funding; Ariad: Research Funding; Sanofi: Membership on an entity's Board of Directors or advisory committees, Research Funding; Teva: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees. Paquette:Incyte: Consultancy. Jamieson:Sunesis: Membership on an entity's Board of Directors or advisory committees; Blue Distinction Centers for Transplants BlueCross BlueShield Association: Consultancy. Lyons:Amgen: Consultancy, Research Funding; Incyte: Consultancy, Research Funding; Novartis: Research Funding. Tiu:Incyte: Honoraria, Speakers Bureau. Winton:Incyte Corporation: Consultancy, Honoraria. Odenike:Incyte: Membership on an entity's Board of Directors or advisory committees; Sanofi-Aventis:Membership on an entity's Board of Directors or advisory committees. Peng:Incyte: Employment, Equity Ownership. Sandor:Incyte: Employment, Equity Ownership. O'Neill:Incyte: Employment, Equity Ownership. Erickson-Viitanen:Incyte: Employment, Equity Ownership. Leopold:Incyte: Employment, Equity Ownership. Levy:Incyte: Employment, Equity Ownership. Kantarjian:Incyte Corporation: grant support Other. Verstovsek:Incyte Corporation: Research Funding.

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Randomized Phase II Study Evaluating the Efficacy and Safety of Romiplostim Treatment of Patients with Low or Intermediate Risk Myelodysplastic Syndrome (MDS) Receiving Lenalidomide.

Blood ◽

10.1182/blood.v114.22.1770.1770 ◽

2009 ◽

Vol 114 (22) ◽

pp. 1770-1770 ◽

Cited By ~ 6

Author(s):

Roger M Lyons ◽

Richard A. Larson ◽

Michael A. Kosmo ◽

Sunil Gandhi ◽

Delong Liu ◽

...

Keyword(s):

Bone Marrow ◽

Research Funding ◽

Intermediate Risk ◽

Employment Equity ◽

Treatment Groups ◽

Platelet Counts ◽

Equity Ownership ◽

Clinically Significant ◽

Dose Reductions ◽

Platelet Transfusions

Abstract Abstract 1770 Poster Board I-796 Introduction Romiplostim is a peptibody protein designed to increase platelet production by binding to and activating the thrombopoietin receptor. Low platelet counts in patients with myelodysplastic syndromes (MDS) may be due to the underlying disease or to treatment with disease-modifying agents, and platelet transfusions are often the only treatment for clinically significant thrombocytopenia (CST) or bleeding. This was a phase 2 multi-center, randomized, double-blind, placebo-controlled, dose-finding study that evaluated the effect of romiplostim on the incidence of clinically significant thrombocytopenic events (grade 3 or 4 thrombocytopenia and/or receipt of platelet transfusions) and the safety of romiplostim in patients with low or intermediate risk MDS receiving lenalidomide. Patients and Methods Patients who were ≥18 years old, had MDS by bone marrow exam and WHO criteria, had low or Intermediate-1 risk category MDS using the IPSS, and were planning to receive lenalidomide were eligible. Patients were randomized 1:1:1 into treatment groups receiving placebo, 500 μg romiplostim, or 750 μg romiplostim by weekly subcutaneous injections in combination with lenalidomide (one 10 mg capsule by mouth daily for each 28-day cycle). Treatments continued for a total of four cycles. Results The median age of the 39 randomized patients was 74 years (range, 39 to 90); 15 (39%) had platelet counts <50 × 109/L, and 7 (18%) had del(5q). We report trends due to baseline imbalances between treatment groups, likely due to the limited sample size. The overall incidence rates of CST appeared to be greater in the placebo group than either romiplostim group (Table). In contrast to the placebo patients, median platelet counts remained above 50 × 109/L in both the 500 μg and 750 μg romiplostim groups for the treatment period. The incidence of platelet transfusions appeared to be lower in the 500 μg romiplostim group, and the incidence of adverse events was comparable between all of the groups. No deaths were reported during the treatment period. Twelve patients (31%) discontinued the study. Disease progression to AML was reported in 1 patient in the romiplostim 500 μg group. The patient withdrew consent and discontinued the study. No bone marrow was available to confirm AML by protocol-defined criteria. Fewer lenalidomide dose reductions and delays due to thrombocytopenia were seen in both of the romiplostim treated groups. The proportion of patients who achieved an MDS treatment response was 8%, 36% and 15% for the placebo, 500 μg romiplostim, and 750 μg romiplostim groups, respectively. MDS response rates appeared higher in the romiplostim group, regardless of baseline del(5q) status. Baseline imbalance between groups due to the small sample size limited our interpretation of the data. Conclusions Romiplostim appeared to be well-tolerated in low and intermediate risk MDS patients receiving lenalidomide. This preliminary information suggests that romiplostim may reduce the rate of clinically significant thrombocytopenic events in these patients while increasing platelet counts and decreasing the incidence of lenalidomide dose reductions and delays due to thrombocytopenia Disclosures Lyons: GlaxoSmithKline: Consultancy, Speakers Bureau; Johnson&Johnson: Consultancy, Honoraria, Speakers Bureau; Celgene: Consultancy; Amgen Inc.: Consultancy, Honoraria, Research Funding, Speakers Bureau. Off Label Use: Use of romiplostim to treat Thrombocytopenia in MDS. Larson:Amgen Inc.: Equity Ownership, Research Funding. Liu:Amgen Inc.: Honoraria, Research Funding. Hu:Amgen Inc.: Employment, Equity Ownership. Franklin:Amgen Inc.: Employment, Equity Ownership. Berger:Amgen Inc.: Employment, Equity Ownership.

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Plerixafor (Mozobil ®)Plus G-CSF Is Effective in Mobilizing Hematopoietic Stem Cells in Patients with Concurrent Thrombocytopenia Undergoing Autologous Hematopoietic Stem Cell Transplantation.

Blood ◽

10.1182/blood.v114.22.3229.3229 ◽

2009 ◽

Vol 114 (22) ◽

pp. 3229-3229 ◽

Cited By ~ 1

Author(s):

Ivana N Micallef ◽

Eric Jacobsen ◽

Paul Shaughnessy ◽

Sachin Marulkar ◽

Purvi Mody ◽

...

Keyword(s):

Stem Cell ◽

Platelet Count ◽

Board Of Directors ◽

Research Funding ◽

Advisory Committees ◽

Hematopoietic Stem ◽

Platelet Counts ◽

Cd34 Cells ◽

Low Platelet Count ◽

Equity Ownership

Abstract Abstract 3229 Poster Board III-166 Introduction Low platelet count prior to mobilization is a significant predictive factor for mobilization failure in patients with non-Hodgkin's lymphoma (NHL) or Hodgkin's disease (HD) undergoing autologous hematopoietic stem cell (HSC) transplantation (auto-HSCT; Hosing C, et al, Am J Hematol. 2009). The purpose of this study is to assess the efficacy of HSC mobilization with plerixafor plus G-CSF in patients with concomitant thrombocytopenia undergoing auto-HSCT. Methods Patients who had failed successful HSC collection with any mobilization regimen were remobilized with plerixafor plus G-CSF as part of a compassionate use program (CUP). Mobilization failure was defined as the inability to collect 2 ×106 CD34+ cells/kg or inability to achieve a peripheral blood count of ≥10 CD34+ cells/μl without having undergone apheresis. As part of the CUP, G-CSF (10μg/kg) was administered subcutaneously (SC) every morning for 4 days. Plerixafor (0.24 mg/kg SC) was administered in the evening on Day 4, approximately 11 hours prior to the initiation of apheresis the following day. On Day 5, G-CSF was administered and apheresis was initiated. Plerixafor, G-CSF and apheresis were repeated daily until patients collected the minimum of 2 × 106 CD34+ cells/kg for auto-HSCT. Patients in the CUP with available data on pre-mobilization platelet counts were included in this analysis. While patients with a platelet count <85 × 109/L were excluded from the CUP, some patients received waivers and were included in this analysis. Efficacy of remobilization with plerixafor + G-CSF was evaluated in patients with platelet counts ≤ 100 × 109/L or ≤ 150 × 109/L. Results Of the 833 patients in the plerixafor CUP database, pre-mobilization platelet counts were available for 219 patients (NHL=115, MM=66, HD=20 and other=18.). Of these, 92 patients (NHL=49, MM=25, HD=8 and other=10) had pre-mobilization platelet counts ≤ 150 × 109/L; the median platelet count was 115 × 109/L (range, 50-150). The median age was 60 years (range 20-76) and 60.4% of the patients were male. Fifty-nine patients (64.1%) collected ≥2 × 109 CD34+ cells/kg and 13 patients (14.1%) achieved ≥5 × 106 CD34+ cells/kg. The median CD34+ cell yield was 2.56 × 106 CD34+ cells/kg. The proportion of patients proceeding to transplant was 68.5%. The median time to neutrophil and platelet engraftment was 12 days and 22 days, respectively. Similar results were obtained when efficacy of plerixafor + G-CSF was evaluated in 29 patients with platelet counts ≤ 100 × 109/L (NHL=12, MM=10, HD=3 and other=4). The median platelet count in these patients was 83 × 109/L (range, 50-100). The median age was 59 years (range 23-73) and 60.4% of the patients were male. The minimal and optimal cell dose was achieved in 19(65.5%) and 3(10.3%) patients, respectively. The median CD34+ cell yield was 2.92 × 106 CD34+ cells/kg. The proportion of patients proceeding to transplant was 62.1%. The median time to neutrophil and platelet engraftment was 12 days and 23 days, respectively. Conclusions For patients mobilized with G-CSF alone or chemotherapy ±G-CSF, a low platelet count prior to mobilization is a significant predictor of mobilization failure. These data demonstrate that in patients with thrombocytopenia who have failed prior mobilization attempts, remobilization with plerixafor plus G-CSF allows ∼65% of the patients to collect the minimal cell dose to proceed to transplantation. Thus, in patients predicted or proven to be poor mobilizers, addition of plerixafor may increase stem cell yields. Future studies should investigate the efficacy of plerixafor + G-CSF in front line mobilization in patients with low platelet counts prior to mobilization. Disclosures Micallef: Genzyme Corporation: Membership on an entity's Board of Directors or advisory committees, Research Funding. Jacobsen:Genzyme Corporation: Research Funding. Shaughnessy:Genzyme Corporation: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Marulkar:Genzyme Corporation: Employment, Equity Ownership. Mody:Genzyme Corporation: Employment, Equity Ownership. van Rhee:Genzyme Corporation: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding.

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ABT-737 Targets Leukemic Stem Cells In Mouse Models of Mutant NRASD12/hBCL-2- Mediated Acute Myeloid Leukemia Progression with Increased Survival

Blood ◽

10.1182/blood.v116.21.3308.3308 ◽

2010 ◽

Vol 116 (21) ◽

pp. 3308-3308

Author(s):

Rose Ann Padua ◽

Stephanie Beurlet ◽

Patricia Krief ◽

Nader Omidvar ◽

Carole Le Pogam ◽

...

Keyword(s):

Stem Cells ◽

Disease Progression ◽

Board Of Directors ◽

Research Funding ◽

Leukemic Stem Cells ◽

Spleen Cells ◽

Employment Equity ◽

Advisory Committees ◽

Equity Ownership ◽

Bh3 Mimetic

Abstract Abstract 3308 Background: Animal models enable us to understand disease progression and provide us with reagents to test various therapeutic strategies. We have previously developed a mouse model of myelodysplasia/acute myelogenous leukemia (MDS/AML) progression using mutant NRASD12 and overexpression of human hBCL-2 (Omidvar et al Cancer Res 67:11657-67, 2007). Expanded leukemic stem cells (LSC) were identified as Lin-/Sca1+/KIT+ (LSK) populations, with increased myeloid colony growth and were transplantable. Increased hBCL-2 and RAS-GTP complex were observed in both MDS/AML diseases. The MDS-like disease had increased apoptosis, whilst the AML-like mice had liver apoptosis patterns similar to wild type. The single NRASD12 line also had increased apoptosis. In this present study using a BCL-2 homology domain 3 (BH3) mimetic ABT-737 (Abbott), we have evaluated the effects of targeting BCL-2 in our preclinical models. Methods & Results: Treatment with the inhibitor shows a reduction of LSK cells, reduced progenitor numbers in colony assays and clearance of the liver infiltrations in both MDS and AML models. Gene expression profiling of the MDS mice shows regulation of 399 genes upon treatment including 58 genes expressed by the single mutant RAS mice and not expressed in the untreated AML mice. 78 genes were shared between single NRASD12 and diseased mice and not the treated mice. These studies potentially identify the contribution of NRASD12 genes to disease progression. By confocal microscopy we observed that in the MDS mice the majority of the RAS and BCL-2 co-localized to the plasma membrane, where active pro-apoptotic RAS is normally located, whereas in the AML disease RAS and BCL-2 co-localized in the mitochondria, where BCL-2 is normally found (Omidvar et al 2007). After treatment with the inhibitor the AML co-localization of RAS and BCL-2 shifted to the plasma membrane where single NRASD12 is normally localized. Furthermore, increased RAS-GTP levels was detected in both Sca1+ and Mac1+ enriched spleen cells and interestingly an increase in BCL-2 expression was observed in peripheral blood and in spleen cells after treatment; this increase in BCL-2 was associated with a decrease in the phosphorylation of serine 70 and an increase in phosphorylation of threonine 56 of BCL-2. ABT-737 treatment led to increased phosphorylated ERK resembling RAS and reduced MEK and AKT phosphorylation, changes detected by western blots and the nanoimmunoassay (NIA, NanoPro, Cell Biosciences) that might account for the increased apoptosis, measured by TUNEL and In vivo imaging by single-photon emission computed tomography (SPECT) using Tc-99m-labelled AnnexinV (SPECT). In contrast, although treated MDS mice had increased apoptosis they did not have an increase in overall expression of BCL-2 or in RAS-GTP levels. Treatment of both MDS and AML models with this inhibitor significantly extended lifespan from diagnosis with mean survival of 28 days untreated vs 80 days treated (p=0.0003) and mean survival from birth of 39 untreated vs 85 days treated (p<0.0001) respectively Conclusions: Genomics, proteomics and imaging have been employed in the MDS/AML models to characterize disease progression and follow response to treatment to the BH3 mimetic ABT-737 in order to gain molecular insights in the evaluation of the efficacy. ABT-737 appears to target LSCs, induce apoptosis, regulating RAS and BCL-2 signalling pathways, which translated into significantly increased survival. Disclosures: Padua: Vivavacs SAS: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees. Auboeuf:GenoSplice technology: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees. de la Grange:GenoSplice technology: Employment, Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties. Fenaux:Celgene: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Janssen Cilag: Honoraria, Research Funding; ROCHE: Honoraria, Research Funding; AMGEN: Honoraria, Research Funding; GSK: Honoraria, Research Funding; Merck: Honoraria, Research Funding; Cephalon: Honoraria, Research Funding. Tu:Cell Biosciences Inc;: Employment. Yang:Cell Biosciences Inc;: Employment. Weissman:Amgen, Systemix, Stem cells Inc, Cellerant: Consultancy, Employment, Equity Ownership, Membership on an entity's Board of Directors or advisory committees. Felsher:Cell Bioscience:. Chomienne:Vivavacs SAS: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees.

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