scholarly journals The Ribosomal Biogenesis Inhibitor CX-5461 Is an Anti-Cancer Therapeutic That Increases Platelet Count in Mice and in Humans

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 2360-2360
Author(s):  
Amandeep Kaur ◽  
Katherine M Hannan ◽  
Samina Nazir ◽  
Kylee H Maclachlan ◽  
Gretchen Poortinga ◽  
...  
Keyword(s):  
Platelet Count ◽  
Board Of Directors ◽  
Platelet Function ◽  
Research Funding ◽  
Ex Vivo ◽  
Liver Carcinoma ◽  
Advisory Committees ◽  
Platelet Counts ◽  
Platelet Spreading ◽  
Disease Free

Background: The ribosomal biogenesis inhibitor CX-5461 is a first-in-class selective inhibitor of ribosomal RNA gene transcription with single-agent antitumor activity against advanced hematologic cancers and synergistic activity when combined with front-line and emerging agents (Devlin et al. 2015, Sornkom et al. 2018, Maclachlan et al. 2018). It has predictable pharmacokinetics and a safety profile allowing prolonged dosing (Khot et al, Cancer Discov 2019). Unexpectedly, CX-5461 treatment increases platelet count by ~50% in tumour diseased mice; an effect that was maintained for up to 6 months of treatment. Aims: We investigated mechanisms that may contribute to increased platelet counts following CX-5461 treatment in a liver carcinoma mouse model or disease-free mice and evaluated blood test data from patients with haematological malignancies treated with CX-5461. Methods: We evaluated blood cell numbers in blood from vehicle- or CX-5461 treated mice with liver carcinoma, and blood cell numbers, bone marrow megakaryocytes, platelet receptors, immature platelets, platelet function, thrombopoietin (TPO) and inflammatory cytokine levels in disease-free C57BL/6 KaLwRij mice treated with 35 mg/kg CX-5461 or vehicle (n=15). Human platelet receptors and function were assessed in CX-5461-treated platelet-rich plasma by flow cytometry, platelet spreading assays and light transmission aggregometry. We evaluated temporal platelet count, and the platelet activation marker soluble glycoprotein (GP) VI in patient plasma samples who had received a single dose of 25-250 mg/m2 CX-5461 (n=16) with 1-way ANOVA. Results: In a model of liver carcinoma, mice with disease displayed significantly elevated (2.3-fold) platelet counts after 3 months treatment with biweekly injections of 35 mg/kg CX-5461 compared with vehicle-treated diseased mice (p = 0.0013). Disease-free mice treated for 7 or 14 days (3 or 6 x 35 mg/kg doses) with CX-5461 showed ~60% increase in platelet count; in comparison white and red cells were mildly suppressed. The CX-5461-mediated platelet increase at d7 (p<0.0005) was reversible within 1 week. At d14 (p<0.01, 1.7-fold increase in platelet count) a significant increase in megakaryocytes (p<0.05) and immature platelets (p<0.01) was observed. CX-5461 treatment had no effect on plasma TPO, platelet lifespan or platelet GPVI or GPIbα levels. Integrin αIIb was significantly elevated. Inflammatory cytokines interleukin (IL)-6 (p<0.05) and TNFα (p<0.01) increased at d7 in plasma. After pre-treatment for 30 min with CX-5461 ex vivo, human platelet function (aggregation and platelet spreading on collagen and fibrinogen) and receptor levels were normal. In 8/16 patients receiving CX-5461, increases of up to 34% in platelet counts were measured at day 15 of CX-5461 treatment, with no change in sGPVI. Conclusions: CX-5461 treatment of mice for two weeks increased platelet counts, megakaryocyte number and immature platelet fraction by an unknown mechanism however IL-6 has been reported by others to enhance megakaryopoeisis. Brief CX-5461 treatment in a group of patients with advanced haematological malignancy resulted in small increases in platelet count with retained platelet activation and treatment ex-vivo demonstrated platelet function to be unaffected. Future work will explore the link between CX-5461 treatment and megakaryopoiesis and thrombopoiesis, including the potential for CX-5461 to ameliorate drug-induced thrombocytopenia. Disclosures Harrison: Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen Cilag: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; GSK: Consultancy, Research Funding; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: investigator on studies, Research Funding; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Hannan:Pimera: Membership on an entity's Board of Directors or advisory committees, Research Funding.

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

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3229-3229 ◽  
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.

Evaluation of Bleeding-Related Episodes in Patients with Chronic Immune Thrombocytopenia (ITP) Treated with Romiplostim in Two Phase 3 Placebo-Controlled Clinical Trials.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 891-891 ◽  
Author(s):  
Ilene Ceil Weitz ◽  
Miguel A Sanz ◽  
David H. Henry ◽  
Martin Schipperus ◽  
Bertrand Godeau ◽  
...  
Keyword(s):  
Platelet Count ◽  
Board Of Directors ◽  
Research Funding ◽  
Rescue Medication ◽  
Bleeding Event ◽  
Bleeding Events ◽  
Phase 3 ◽  
Advisory Committees ◽  
Platelet Counts ◽  
Chronic Itp

Abstract Abstract 891 Background: Chronic Immune thrombocytopenia (ITP) is characterized by low platelet counts and increased risk of bleeding. Rescue medications used to treat or prevent bleeding produce transient increases in platelet counts but may be associated with additional toxicities and costs. Romiplostim, approved for the treatment of adult chronic ITP, is a TPO mimetic peptibody protein that increases platelet production. Previously published data from phase 3 romiplostim trials showed that despite the increased use of rescue medication in the placebo arm, patient (pt) incidence of bleeding was reduced in the romiplostim arm vs placebo arm: 15% vs 34% (p = 0.02) for bleeding of grade ≥2 severity and 7% vs 12% (p=0.36) for grade ≥3 severity. Objective: To evaluate the effects of romiplostim treatment on bleeding outcomes in the phase 3 placebo controlled studies in chronic ITP pts with and without previous splenectomy. Bleeding events were captured as adverse events making it difficult to identify a single event reported multiple times versus persistent or recurrent bleeding. Further, we have developed a composite endpoint, termed bleeding-related episodes (BREs), which combines bleeding events and rescue medication administration to account for use of rescue medications to prevent bleeding. Methods: Adults with chronic ITP and a mean baseline platelet count <30 × 109/L were eligible. The previously published studies were conducted separately in splenectomized and nonsplenectomized populations. Pts were randomized (2:1) to receive romiplostim or placebo by subcutaneous injection once weekly for 24 weeks, with dose adjustments to maintain platelet counts between 50-200 × 109/L. Rescue medications were permitted to treat or prevent bleeding and included immunoglobulins, platelet transfusions, corticosteroids, or an increase in dose or frequency of a concurrent ITP medication. A BRE was defined as an actual bleeding event and/or the use of rescue medication. To collapse related events into episodes, events (bleeding events and/or the use of rescue medication) that occurred concurrently or within 3 days of each other were considered a single BRE. Bleeding events beginning 7 or more days after the start of the initial bleeding event were considered a new BRE. To account for differences in time spent on-study, rates of BRE per 100 pt-weeks were calculated. Results: A total of 125 pts (41 placebo, 84 romiplostim) were enrolled in the two studies. Baseline characteristics were well-balanced between the placebo and romiplostim-treated groups. During the treatment period, the rate of BREs was lower in the romiplostim group than in the placebo group, and results were consistent between splenectomized and nonsplenectomized pts (Table). Across both studies, the rate of BREs was reduced by 55% in pts receiving romiplostim compared to those receiving placebo (95% CI, 41% to 65%). BREs were more frequent at platelet counts <50 × 109/L (Table). BREs associated with hospitalizations were less common among romiplostim- than placebo-treated pts, and occurred at platelet counts <50 × 109/L in 10 of 11 cases. Corticosteroids (58 romiplostim, 38 placebo) and immunoglobulins (30 romiplostim, 73 placebo), were the most commonly used rescue medications and the rate of BREs including immunoglobulins was reduced by 88% in pts receiving romiplostim compared to placebo. Conclusions: In adults with chronic ITP, romiplostim was associated with a significant reduction in BREs compared to placebo. There was a marked reduction in BREs requiring immunoglobulins in the romiplostim arm compared to the placebo arm. Results were comparable in splenectomized and nonsplenectomized populations. The platelet count for a BRE starting ≥1 day after a platelet count measurement was calculated from the 2 proximal weekly measurements. Disclosures: Weitz: Amgen Inc.: Speakers Bureau. Sanz:Amgen Inc.: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Henry:Amgen Inc.: Research Funding, Speakers Bureau; Orthobiotech: Research Funding, Speakers Bureau; Watson Pharma: Research Funding, Speakers Bureau. Schipperus:Amgen Inc.: Membership on an entity's Board of Directors or advisory committees. Godeau:Amgen Inc.: Consultancy, Research Funding; Laboratoire Français de Fractionnement et de Biotechnologies (LFB): Consultancy; Roche: Research Funding. Gleeson:Amgen Inc.: Consultancy, Research Funding. Danese:Amgen Inc.: Consultancy, Research Funding. Deuson:Amgen Inc.: Employment, Equity Ownership.

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 ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 3279-3279 ◽  
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.

Sports Participation in Children with ITP: A Case for Liberalization?

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 3339-3339 ◽  
Author(s):  
Sophie Brigstocke ◽  
Catherine E. McGuinn ◽  
James B Bussel
Keyword(s):  
Platelet Count ◽  
Board Of Directors ◽  
Research Funding ◽  
Sports Participation ◽  
Contact Sport ◽  
Advisory Committees ◽  
Contact Sports ◽  
Platelet Counts ◽  
Risk Of Injury ◽  
Frequency Of Sports Participation

Abstract Abstract 3339 Background: Children with ITP are at risk for bleeding. ITP is one of many conditions for which the American Academy of Pediatrics advises a pre-sports participation evaluation to assess the risk of injury (Rice 2008). However, restrictions in sports participation might deny the many evidence-based benefits of such physical activity usually accessible for US school-aged youth, thereby presenting significant health and quality of life issues. Aims: To better assess the frequency of sports participation and sports-related injury outcomes relative to contact level by gathering data via questionnaire from a convenience sample of children with persistent and chronic ITP. Methods: Fourteen different types of sports activities were included in this IRB-approved questionnaire and were classified as contact, limited contact, or non-contact as determined by the American Academy of Pediatrics Council on Sports Medicine and Fitness (Rice 2008). Questions were aimed at the frequency of sports participation, types of sports played, sports-related injuries (including bleeding), medical care required for injuries, and comfort regarding continued participation in a sport after sustaining an injury. For each sport not played, questions assessed reasons for the subject's decision to refrain from participation. Patients were categorized according to their platelet levels: counts ≤ 50, 50–150, >150; counts ≤ or >50; counts ≤ or >30 (×109/L). Proportions of data involving 2 groups were compared in a contingency table using Fisher's exact test with trends ≤ 0.01 and significance ≤ 0.025. Results: Twelve subjects (19%) did not participate in any sports. Thirty-six (56%), including patients across all platelet counts, participated in at least one contact sport. There was no statistically significant association (p > 0.1) between the subject's platelet count and the contact level of sport chosen to play. However, a significant association was found between higher frequency of sports participation and higher platelet count (analyzed by groups ≤ or >50 and counts ≤ or >30 (×109/L)) when the highest frequency of participation in any sport (regardless of contact level) was assessed (p < 0.025). When only the sport with the highest contact rating was considered, patients with higher counts played their highest contact sport more frequently than did those patients with lower counts. In particular, subjects with counts ≤ 30 ×109/L played their highest contact sport less frequently, eg more commonly < 1x/month, compared to subjects with platelet counts > 30 ×109/L who played more commonly > 1x/month (p=0.025) [figure]. Twenty injuries were recorded across 10 different sports and 17 patients, but no serious bleeding injuries were reported. There was a statistically significant association (p = 0.002) between higher contact levels and greater incidence of injury. However, there was no statistically significant association (p > 0.1) between estimated platelet count at time of injury and the contact level of sport. As recorded by the patients and/or the patients' parents, 26% of general concerns came from physicians, 53% from parents and 21% from patients themselves. Data collected on the participants' personal concerns showed that higher platelet counts were associated with fewer personal concerns being expressed (p < 0.025). However, when each personal concern was analyzed there were no statistically significant trends or associations (p > 0.1) found between any specific concern and platelet count. Across all contact and limited-contact sports, the most frequently expressed concern was that the sport was too dangerous. The most frequently expressed concern for non-contact sports was that the patient was too tired to play. Conclusions: There was a significant association between higher frequency of sports participation, but not higher contact level, with higher platelet counts. Higher incidences of injury were associated with higher contact levels, but not with lower platelet counts, suggesting that children with ITP can participate in non-contact sports and many contact and limited-contact sports with low risk of injury. Therefore, we believe that sports participation for children with ITP is generally too restricted and greater encouragement for children to be athletic in the sport of their choice is warranted. Disclosures: Bussel: Sysmex: Research Funding; Shionogi: Membership on an entity's Board of Directors or advisory committees, Research Funding; Eisai: Membership on an entity's Board of Directors or advisory committees, Research Funding; Ligand: Membership on an entity's Board of Directors or advisory committees, Research Funding; Immunomedics: Research Funding; IgG of America: Research Funding; Genzyme: Research Funding; GlaxoSmithKline: Family owns GSK stock, Family owns GSK stock Other, Membership on an entity's Board of Directors or advisory committees, Research Funding; Cangene: Research Funding; Amgen: Family owns Amgen stock Other, Membership on an entity's Board of Directors or advisory committees, Research Funding; Portola: Consultancy.

scholarly journals Hepatobiliary and Thromboembolic Events during Long-Term E.X.T.E.N.Ded Treatment with Eltrombopag in Adult Patients with Chronic Immune Thrombocytopenia (ITP)

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 1368-1368
Author(s):  
Mansoor N. Saleh ◽  
James B Bussel ◽  
Raymond SM Wong ◽  
Balkis Meddeb ◽  
Abdulgabar Salama ◽  
...  
Keyword(s):  
Platelet Count ◽  
Board Of Directors ◽  
Research Funding ◽  
Adult Patients ◽  
Phase Iii ◽  
First Year ◽  
Thromboembolic Events ◽  
Advisory Committees ◽  
Platelet Counts

Abstract Introduction: ITP, characterized by a reduction in platelets leading to thrombocytopenia, which persists for >12 months is considered chronic (cITP). Eltrombopag is an oral thrombopoietin receptor agonist approved for treatment of patients with cITP aged ≥1 year refractory to other treatments (eg corticosteroids, immunoglobulins). The recently completed Phase III EXTEND (Eltrombopag eXTENded Dosing) study was a global, open-label, extension study of patients with cITP, who received eltrombopag or placebo in prior eltrombopag clinical studies. The primary objective of EXTEND was to describe the long-term safety and tolerability of eltrombopag treatment in these patients. Here, we examine the occurrence of hepatobiliary and thromboembolic events (TEEs) as adverse events (AEs) of special interest in this study. Methods :Adult patients (≥18 years old) diagnosed with cITP according to ASH/BCSH guidelines were enrolled and received eltrombopag starting at 50 mg/day. Dose was titrated to 25-75 mg per day or less often as required, based on individual platelet count responses (targeted range ≥50-200x109/L). Patients who received 2 years of treatment and transitioned off eltrombopag due to commercial availability of eltrombopag were considered to have completed the study, whether or not they continued treatment with eltrombopag. The primary endpoint included detection and documentation of investigator-reported AEs, which included hepatobiliary AEs and TEEs. Analyses were conducted using the safety population, defined as all subjects who entered the study and had taken at least one dose of the study medication. Results:302 patients were enrolled and received at least one dose of eltrombopag: 67% were female; 38% splenectomized; 49% aged 18-49 years. Median duration of exposure was 2.4 years (range, 2 days to 8.8 years) and mean average daily dose was 50.2 (range, 1-75) mg/day. Overall, 259/302 (86%) achieved platelet counts of ≥50×109/L at least once during the study and 126/248 (51%) patients maintained continuous platelet counts ≥50×109/L for at least 31 weeks. Incidence of bleeding symptoms (WHO grades 1-4) generally decreased over time in patients with available data, from 57% (n=171/302) at baseline to 16% at 1 year (n=13/80), and 21% (12/58) at 2 years. 45 (15%) patients experienced at least one hepatobiliary AE, with the highest incidence within the first year of treatment (Figure A). AEs of increased ALT or AST led to the discontinuation of five and three patients, respectively and four patients discontinued due to an AE of increased blood bilirubin. Nine patients experienced ALT and/or AST >3 x upper limit of normal (ULN) and total bilirubin >1.5xULN. 19 (6.3%) patients experienced a total of 23 TEEs. Most events occurred in the first year (Figure B), and none after year 4. TEEs included deep vein thrombosis (n=6), cerebral infarction (stroke) [n=3], myocardial infarction (n=4), transient ischemic attack (n=2), others (n=8, 1 occurrence of each). A clear association with elevated platelet counts was not observed. Platelets >200x109/L at the time of the TEE were recorded in 8/19 patients; 6/19 experienced the TEE at or shortly after achieving their maximum platelet count. In total, 10 patients discontinued because of TEEs. Conclusions: Long-term treatment with eltrombopag in patients with cITP led to sustained platelet increases and reduced bleeding symptoms. The highest incidences of hepatobiliary AEs and TEEs occurred during the first year of treatment, though several events were recorded after 3 years of therapy. Long-term eltrombopag therapy was well-tolerated with a positive benefit-risk relationship in adults with cITP, with decreasing events after the first year of treatment. Disclosures Saleh: GSK: Consultancy, Research Funding, Speakers Bureau. Bussel:Amgen, Novartis & GSK: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Boehringer Ingleheim, Prophylix Pharma, Protalex, Rigel Pharmaceuticals: Research Funding; Momenta Pharmaceuticals, Novartis, Prophylix Pharma, Protalex, Rigel Pharmaceutical: Membership on an entity's Board of Directors or advisory committees; UptoDate: Patents & Royalties; Physicians Education Resource: Speakers Bureau. Wong:Bayer, Biogen-Idec and Novartis: Consultancy; Bayer, Biogen-Idec, Bristol-Myers Squibb, GlaxoSmithKline, Johnson & Johnson, Merck Sharp & Dohme, Novartis, Pfizer, and Roche: Research Funding; Biogen-Idec and Novartis: Membership on an entity's Board of Directors or advisory committees. El-Ali:Novartis: Employment. Quebe-Fehling:Novartis: Employment.

scholarly journals Safety and Efficacy of Romiplostim in over 200 Children with Immune Thrombocytopenia (ITP): Results of an Integrated Database of 5 Clinical Trials

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 2428-2428 ◽  
Author(s):  
Michael D. Tarantino ◽  
Jenny M. Despotovic ◽  
John Roy ◽  
John Grainger ◽  
Nichola Cooper ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Platelet Count ◽  
Board Of Directors ◽  
Research Funding ◽  
Platelet Response ◽  
Open Label ◽  
Advisory Committees ◽  
Baseline Platelet Count ◽  
Platelet Counts

Abstract Background: Romiplostim is approved globally for use in adults with ITP and in the EU for children with ITP. More comprehensive data are needed on the use of romiplostim in children with ITP. Objective: To examine the safety and efficacy of romiplostim in trials in children with ITP. Methods: Data were combined from 5 romiplostim trials in children with ITP, both placebo-controlled (a phase 1/2 and a phase 3 trial) and open-label (a 3-year trial and 2 extension trials); trial data have been reported previously (Bussel Blood 2011, Bussel PBC 2014, Tarantino Lancet 2016, Tarantino ASH 2017, Grainger ASH 2017). Platelet counts in the 4 weeks after use of rescue medication were excluded from analyses. Descriptive statistics were used. Number (n), mean, standard deviation (SD), median, quartile range (Q1, Q3), minimum (min), and maximum (max) for continuous variables, and number and percentage for categorical variables were provided. Results: Patients (N=286, 24 initially placebo and 262 initially romiplostim) had median (Q1, Q3) age of 10 (6, 13) years, ITP duration of 1.9 (1, 4) years, and baseline platelet count of 14 (8, 23)×109/L. Previously, 88% had received corticosteroids, 87% IVIg, and 21% rituximab; 23% had received >3 prior treatments and 7% had prior splenectomy. Of the 282 patients exposed to romiplostim (20 initially received placebo), the median (min, max) duration of treatment was 65 (8, 471) weeks, with a median (min, max) average weekly dose of 6.6 (0.1, 9.7) μg/kg; total exposure was 468 patient-years. The most common reasons for discontinuing the parent study for romiplostim-treated patients were per protocol (19%; eg, sponsor decision, death, lost to follow-up), consent withdrawn (3%), noncompliance (1%), and administrative decision (1%). Of romiplostim-treated patients, 24% had serious adverse events (SAEs), most commonly epistaxis, low platelet counts, and headache (Table). There were 7 cases of postbaseline neutralizing antibody against romiplostim: 2 transient and 5 persistent. There were no neutralizing antibodies against endogenous TPO. For patients undergoing bone marrow biopsies in the 3-year open-label trial, there were no findings of collagen or bone marrow abnormalities (Year 1 n=27, Year 2 n=5, vs. baseline) (Grainger et al, ASH 2017). One patient had an increase in modified Bauermeister bone marrow grade from 0 to 2 (fine reticulin fiber network) with no associated AEs (the only AEs were a cold and injection site pain); per protocol, there was no follow-up biopsy. Once at a steady dose of 10 μg/kg, most (11/16) of this patient's platelet counts were ≥30×109/L. Investigators reported thrombocytosis AEs; 1 patient had a platelet count of 1462×109/L at Week 14 for 1 week and another had elevated platelet counts 10 times between Weeks 20-172 (max of 872×109/L); there were no associated thrombotic events. Median platelet counts rose quickly and were over 50×109/L from Week 12 on (Figure). Platelet response rates also rose quickly. Overall, 89% of romiplostim-treated patients (vs 8% of placebo) had a platelet response (platelet counts ≥50×109/L; Figure). For romiplostim-treated patients, the first platelet responses occurred after a median of 6 weeks. The median % (Q1, Q3) of months responding was 76% (25%, 93%) and # of months responding was 11 (3, 20); from time of first monthly response, the median (Q1, Q3) % of months responding was 92% (75%, 100%) and # of months responding was 14 (7, 23). Nineteen romiplostim-treated patients discontinued all ITP therapies including romiplostim for ≥6 months while maintaining platelet counts ≥50×109/L (here defined as remission). These treatment-free periods lasted a median (Q1, Q3) of 12 (8, 14) months; no placebo patients remained free of treatment. There were no clear differences between those who did and did not enter remission (ie, age, sex, race, past treatment, ITP duration, baseline platelet count). Bleeding was reported for most (68%) patients: mostly grade 1/2, with 10% having grade 3 bleeding (most commonly epistaxis in 13 patients) and 2 patients having grade 4 bleeding (both reported as "ITP"). Conclusions: In this comprehensive database of romiplostim ITP trials in 286 children with 468 patient-years of romiplostim exposure, romiplostim was well tolerated. With romiplostim, the vast majority (89%) of patients had a platelet response, with some children able to discontinue all ITP treatments for ≥6 months. Disclosures Tarantino: Health Resources and Services Administration: Research Funding; Centers for Disease Control and Prevention: Research Funding; Amgen: Membership on an entity's Board of Directors or advisory committees; Genentech: Membership on an entity's Board of Directors or advisory committees; Shire: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pfizer: Other: Reviews grants; Novo Nordisk: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Grifols: Research Funding, Speakers Bureau. Despotovic:AmGen: Research Funding; Sanofi: Consultancy; Novartis: Research Funding. Grainger:Biotest: Consultancy; Ono Pharmaceuticals: Consultancy; Amgen: Consultancy, Honoraria, Other: Educational grant; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees. Cooper:Amgen, Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Kim:Amgen Inc.: Employment, Equity Ownership. Eisen:Amgen Inc.: Employment, Equity Ownership.

scholarly journals Adolescents and Young Adults with Immune Thrombocytopenia (ITP): A Project of the Carmen-France and Parc-ITP Registry

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 2079-2079
Author(s):  
Alexandra Schifferli ◽  
Guillaume Moulis ◽  
Bertrand Godeau ◽  
Thierry Leblanc ◽  
Marc Michel ◽  
...  
Keyword(s):  
Young Adults ◽  
Platelet Count ◽  
Chronic Disease ◽  
Board Of Directors ◽  
Clinical Data ◽  
Research Funding ◽  
Diagnostic Methods ◽  
Adolescents And Young Adults ◽  
Advisory Committees ◽  
Platelet Counts

Abstract Introduction The prognosis of ITP is age-related. In 80% of cases, children have a self-limiting course, whereas adults recover less frequently or relapse and overall ITP has a chronic course in ~70% of the cases. The risk of chronicity increases above the age of 10 years in pediatric cohorts, but data describing adolescents and young adults (AYAS) are lacking. Based on the assumption that adults are at greater risk of bleeding, treatment protocols and practice guidelines usually advise medical intervention. This is surely the right strategy for elderly patients or those with co-morbidities with indisputable higher bleeding risks. We assume that defining ITP in only two age categories might be an inaccurate oversimplification. AYAS have other needs, such as body appearance, mental health, social and financial issues. In addition, limitation of activity, side effects of steroids and risk of chronic disease are major reasons to adapt medical care. Even if AYAS have a similar risk of chronicity like adults, they may have greater potential to restore immune tolerance -in analogy to children- but with the help of an appropriate immunomodulatory therapy. The analysis of clinical data is the first step to design new strategies. Methods Data were extracted from the PARC-ITP and the CARMEN-France registry, open since 2004 and 2013, respectively. PARC is an international multi-center registry collecting data prospectively of children and adults with newly diagnosed ITP. The CARMEN-France registry enrolls all incident ITP in adults 18 years from the French Midi-Pyrénées region, and since 2016 increasingly in other French centers. Demographics, diagnostic methods, clinical data, management are continuously documented in CARMEN and at defined timepoints in PARC (initial, at 6,12 months follow-up (FU), and then yearly). Patients 12-25 years old with initial platelet counts &lt;100x10 9/l were included. Patients with secondary or misdiagnosed ITP (n=57), and pregnant women were excluded (n=10). Sustained remission was defined as a platelet count 100x10 9/l at 12 months (measured at 11-18 months) and without treatment for at least 6 months. For patients with borderline values (100-149 x10 9/l), later FUs were analyzed to determine the persistency of remission, and, if necessary, reassign patient's remission state. Only bleeding location, but not grade was analyzed in common. Data were analyzed with descriptive statistics. Results A total of 656 AYAS (61% female) with the initial diagnosis of primary ITP were recorded in the combined database until 2021. FU information was available for 547 (83%) and 470 (72%) patients at 6 and 12 months, respectively. Initial median platelet count was 12 x10 9/l (IQR 5). In 109 patients the diagnosis was incidental (17%), 538 patients suffered of bleeding symptoms (82%) (Table 1). At 6 months 49% of patients had platelets &lt;100 x10 9/l. At 12 months 50% fulfilled the criteria of chronic disease, with a median platelet count of 57x10 9/l (IQR 32). Asymptomatic chronic ITP was reported in 40% (no bleeding between 6-12 months). Platelet-enhancing drugs were reported in 66%, 45% and 30% at diagnosis, until 6 months and between 6-12 months, resp. Corticosteroids were preferred at all time-points, second-line treatments were various and given to 29% of patients with treatment beside 6 months (Table1). There were no differences in initial diagnostic procedures, comorbidity, bleeding symptoms, median platelet counts, percentage of severe thrombocytopenia (&lt;20 x10 9/l) and need of treatment and drug choice between women and men (besides gynecological bleeding). There were small differences in the subgroup of adolescents (12-18 years, 59% female) compared to young adults (18-25 years, 70% female), the later had more moderate thrombocytopenia at diagnosis, less bleeding at all FUs, but similar or even more treatments (Table 2). Conclusion This is the first prospective project describing AYAS with a diagnosis of primary ITP. Analysis exhibited a clinical pattern among children and adults, with a risk of chronicity of 50%, and prolonged need of treatment (6-12 months) in 30% of cases. At diagnosis 17% had no bleeding signs, compared to 9% of children and 31% of adults in previous analysis of the PARC. There were no gender differences. Surprisingly, young adults experienced a greater number of non-bleeding phenotype than adolescents at all FUs, with comparable need of treatment between 6-12 months FU. Figure 1 Figure 1. Disclosures Schifferli: Novartis: Honoraria, Research Funding; Sobi: Honoraria. Moulis: Argenx: Membership on an entity's Board of Directors or advisory committees; Sobi: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding; Grifols: Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Membership on an entity's Board of Directors or advisory committees, Research Funding. Godeau: Novartis: Consultancy; Grifols: Consultancy; Sobi: Consultancy; Amgen: Consultancy. Michel: Rigel: Honoraria; Argenx: Honoraria; UCB: Honoraria; Alexion: Honoraria; Amgen: Consultancy; Novartis: Consultancy. Grainger: Amgen: Consultancy, Honoraria; Novartis: Consultancy, Honoraria. Kuehne: Amgen: Research Funding; SOBI: Honoraria; UCB: Honoraria; Novartis: Research Funding.

Thromboembolic Events Observed in Eltrombopag Clinical Trials in Chronic Immune Thrombocytopenic Purpura.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2423-2423 ◽  
Author(s):  
James B. Bussel ◽  
Gregory Cheng ◽  
Mansoor N. Saleh ◽  
Sandra Vasey ◽  
Manuel Aivado ◽  
...  
Keyword(s):  
Platelet Count ◽  
Board Of Directors ◽  
Research Funding ◽  
Thromboembolic Events ◽  
Study Medication ◽  
Normal Range ◽  
Advisory Committees ◽  
Thrombocytopenic Purpura ◽  
Platelet Counts ◽  
Equity Ownership

Abstract Abstract 2423 Poster Board II-400 BACKGROUND: Eltrombopag (PROMACTA®; GlaxoSmithKline, Collegeville, PA, USA), an oral, small molecule, thrombopoietin receptor agonist, was recently approved in the United States for the treatment of patients with chronic immune thrombocytopenic purpura (ITP). Limited published data indicate that patients with chronic ITP experience thromboembolic events (TEEs) with a frequency of 3% to 6%. (Aledort, Am J Hematol, 2004; Bennett, Haematologica, 2008). OBJECTIVE: To evaluate the incidence of TEEs in patients with chronic ITP treated with eltrombopag and to determine if the occurrence of TEEs was associated with elevated platelet counts. METHODS: Data from 446 patients from 3 placebo-controlled eltrombopag studies (TRA100773A, TRA100773B, and RAISE) and 2 open-label studies (REPEAT and EXTEND) were analyzed. The frequency of TEEs or suspected TEEs before and after the first dose of study medication (placebo or eltrombopag) was examined across the program. Potential risk factors, including platelet counts proximal to the event, were evaluated in patients experiencing a TEE. RESULTS: Prior to the initiation of study medication (placebo or eltrombopag), 16/493 (3.2%) of the patients entering the program had a history of TEEs (one of these patients experienced 2 additional TEEs [TIA, MI] while on treatment with eltrombopag). Across the ITP clinical program, 17/446 patients treated with eltrombopag (3.8%) experienced 22 TEEs. No patient treated with placebo experienced a TEE. The patient-years (PYs) of exposure to study medication was approximately 14 times greater for patients treated with eltrombopag compared to placebo (eltrombopag 377 PYs; placebo 26 PYs). Most patients (13/17) experienced 1 TEE; 3 patients experienced 2, and 1 patient experienced 3 (2 TEEs were 6 months off-therapy). The most common TEEs were deep vein thrombosis (n=8) and pulmonary embolism (n=6). A total of 18/22 events were resolved or resolving at the time of this analysis; all patients experiencing a TEE had at least 1 risk factor for these events other than ITP (eg, use of IVIg [n=3], hospitalization with no prophylactic anticoagulation [n=4], oral corticosteroids [n=6]). The platelet counts proximal to the event ranged from 14,000/μL to 420,000/μL. The majority of patients had platelet counts below 150,000/μL (9; 53%) or between 150,000/μL and 400,000/μL (5; 29%); 2 had platelet counts above 400,000/μL and the platelet count in 1 was unknown. All 446 patients were categorized by the maximum platelet count achieved during treatment with eltrombopag (above normal [>400,000/μL], normal range [150–400,000/μL], below normal range [<150,000/μ]; Table 1). The majority of patients (14; 82%) experienced the TEEs at a platelet count lower than their maximum platelet count, while 3 patients (18%) experienced a TEE proximal to their maximum platelet count. CONCLUSION: TEEs occurred with eltrombopag. None occurred with placebo; however, the PYs of exposure was considerably less with placebo than with eltrombopag. The frequency of TEEs observed during eltrombopag treatment (3.8%) is similar to that reported in the literature and prior to enrollment in the eltrombopag program (3.2%). No discernible correlation has been observed between platelet count increases and TEEs, and these events do not appear to be associated with maximum platelet counts during treatment with eltrombopag. Disclosures: Bussel: Sysmex: Research Funding; Eisai, Inc: Research Funding; 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; Cangene: Research Funding; GlaxoSmithKline: Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Research Funding; Genzyme: Research Funding; Scienta: Speakers Bureau; Shionogi: Membership on an entity's Board of Directors or advisory committees. Cheng:GlaxoSmithKline: Research Funding. Saleh:GlaxoSmithKline: Speakers Bureau; Amgen: Speakers Bureau. Vasey:GlaxoSmithKline: Employment. Aivado:GlaxoSmithKline: Employment. Brainsky:GlaxoSmithKline: Employment.

The Effect of Eltrombopag on Platelet Resistance to Apoptosis: The Role of the Bcl-Xl Pathway

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 1158-1158
Author(s):  
W. Beau Mitchell ◽  
Michele N Edison ◽  
Mariana P Pinheiro ◽  
Nayla Boulad ◽  
Bethan Psaila ◽  
...  
Keyword(s):  
Platelet Count ◽  
Board Of Directors ◽  
Research Funding ◽  
De Novo ◽  
Apoptosis Resistance ◽  
Advisory Committees ◽  
Apoptotic Pathway ◽  
Akt Activation ◽  
Platelet Counts ◽  
Equity Ownership

Abstract Abstract 1158 INTRODUCTION: Immune thrombocytopenia (ITP) is typically characterized by increased platelet destruction and reduced platelet production. Eltrombopag and Romiplostim are thrombopoietin receptor (TPO-R) agonists that are known to increase platelet counts in patients with ITP by stimulating thrombopoiesis. Platelets also express TPO-R on their surface, but it is unknown whether the thrombopoietin mimetics (TPO-M) have a direct effect on the circulating platelets. Although controversial, in a very small number of ITP patients, TPO-M agents may increase platelet counts in 2–5 days, earlier than would be expected from de novo megakaryocytopoiesis. Platelet survival is hypothesized to be mediated by two molecular intermediates in an apoptotic pathway, Bcl-xL and Bak. Bcl-xL/Bak protein expression in megakaryocytes is regulated in part by TPO-mediated activation of Akt pathways through Jak2 and Stat5. We hypothesized that an increase in platelet count in the first week of treatment might be mediated by TPO-R signaling, resulting in decreased platelet apoptosis. This study explored whether Eltrombopag or Romiplostim treatment has anti-apoptotic effects on platelets of patients with ITP. METHODS: Following a treatment wash out period, 75 mg of Eltrombopag once daily or 10 mcg/kg weekly of Romiplostim was initiated for 2 weeks. Blood counts were measured on days 1, 3, 5, 8, 10, 12, and 15. Platelet function and survival was assessed on days 1, 8, and 15 by: immature platelet fraction (IPF), glycocalicin index, Bcl-xL inhibitor (ABT-737) assay, measurement of Bcl-xL by western blot, measurement of several members of the Bcl-xL Akt mediated, apoptotic pathway by flow cytometry (FACS), bleeding score, measurement of thrombin-anti-thrombin complexes (TATs), and quantification of microparticles. RESULTS: Eight of 10 patients responded to treatment with Eltrombopag with a platelet count ≥ 50,000/μL, and 6 of the 8 responders at least doubled their counts during the 2 weeks of treatment. All 3 patients treated with Romiplostim responded with platelet count ≥ 50,000/μL. In both treatment groups there was a significant increase in median platelet count (p<0.001), median large platelet count (p<0.01), and median absolute IPF (A-IPF, p<0.01), while there was no significant change in median % IPF. The dose of ABT-737 required to kill half of the platelets in the sample (IC50) in the Eltrombopag group was lower in patients at day 1 than in non-ITP controls, and there was an increase in resistance to apoptosis between days 1 and 8, but these changes did not reach statistical significance. Between days 8 and 15 the IC50 declined to pre-treatment levels. In the Romiplostim group there was no significant difference in IC50 between the control and the patients over the 2 weeks of study. There was no significant correlation between the platelet counts and the IC50 values. FACS analysis of members of the AKT signal transduction pathway revealed increased activation of each of the markers between days 1 and 8, followed by a decrease between days 8 and 15. The levels of Bcl-xL and phosphor-AKT(308) decreased from day 1 to day 15. The other lab tests are pending. DISCUSSION: Because the A-IPF increased by less than the platelet increase and because the lifespan of the A-IPF is not known, it is unclear if the platelet count increase is solely a result of increased platelet production. Platelet lifespan may be enhanced by Eltrombopag treatment as there was a parallel albeit transient increase in AKT activation markers and platelet apoptosis resistance in the Eltrombopag group. Treatment with Romiplostim did not appear to affect apoptosis resistance although it did result in transient AKT activation. Our data suggest that platelets are more resistant to apoptosis when the levels of anti-apoptotic factors (eg. PTEN, Phospho-GSK3β) involved in the AKT/Bcl-xL pathway are greatest despite a concomitant increase in pro-apoptotic factors (eg. Bak, Bax). Since both the increased AKT activation and apoptotic resistance returned to baseline at day 15, megakaryocytes and platelets already present at the start of treatment may respond differently than those generated de novo in the presence of TPO mimetics. 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.

Successful Discontinuation of Eltrombopag Treatment in Patients with Chronic ITP

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 1085-1085 ◽  
Author(s):  
Emily Leven ◽  
Allison Miller ◽  
Nayla Boulad ◽  
Anis Haider ◽  
James B Bussel
Keyword(s):  
Platelet Count ◽  
Board Of Directors ◽  
Research Funding ◽  
Rescue Therapy ◽  
Primary Response ◽  
Additional Treatment ◽  
Advisory Committees ◽  
Platelet Counts ◽  
Rescue Treatment ◽  
Immature Platelet Fraction

Abstract Abstract 1085 Introduction: Patients with immune thrombocytopenia (ITP) commonly experience platelet increases while under treatment with thrombopoietin-receptor agonists (TPO-RA). Anecdotal evidence suggests certain patients have been able to discontinue TPO-RA and still maintain platelet counts above baseline without additional treatment. This prospective ongoing study was designed to investigate the frequency and characteristics of patients exhibiting sustained responses after electively discontinuing eltrombopag (a TPO-RA) without substituting additional therapy. Methods: Enrolled patients were required to have ITP defined by consensus guidelines (Provan, Blood, 2009) for at least 6 months and must have been taking eltrombopag for a minimum of 4 months prior to starting this observational study. Rescue therapy is permitted once in the first 4 weeks off eltrombopag. The primary response endpoint was prospectively defined as a platelet count of ≥30,000/μl and ≥20,000/μl above initial baseline for 6 months off eltrombopag without intervening treatment (other than rescue). The secondary endpoint was being stably off therapy at 4 weeks after discontinuing eltrombopag. All patients who meet the 2 inclusion criteria (ITP for 6 months and eltrombopag for 4 months) are eligible for the study. Results: Fifteen patients are currently enrolled. Ages range from 3 to 86 years, median 55 years, with 10 females. There are 5 responders of 5 months or more (3 females, 2 males) and 10 non-responders (7 females, 3 males). Four of 5 responders have been off therapy for 6 months or more; the fifth “responder” has been off therapy for 5 months, with platelet counts ≥195,000/μL (figure 1). Responders are aged 19–86 years and have had ITP for 5–34 years; all had been on eltrombopag for > 2 years. Two responders were splenectomized and all had 3 or more prior therapies. One responder and 9 non-responders received rescue treatment in the first 4 weeks. One patient was a responder at 4 weeks, but she lost her response before reaching 6 months off-treatment. Factors not significantly associated with response were: age, duration of ITP, duration of eltrombopag therapy, splenectomy status, number of prior ITP treatments, bleeding history, and platelet count at the time that eltrombopag was discontinued. However, a lower absolute immature platelet fraction (AIPF) value at cessation of eltrombopag was seen in responders (fig 2, p=0.022). AIPF data for 1 non-responder is not available. An AIPF of 900 × 10/μl at the time of discontinuation of eltrombopag exceeds the AIPF of all 5 responders, but also of 3 of 9 non-responders. Conclusions: A substantial fraction of patients with ITP treated with eltrombopag, approximately 1/3, appear able to discontinue eltrombopag treatment and nonetheless maintain an at least adequate platelet count indefinitely (at the very least 6 months). Similar preliminary data has been reported with romiplostim (EHA and ASH abstracts). AIPF values (platelet retics) may better predict a patient's likelihood of successfully stopping therapy than other variables such as those listed above. Disclosures: Bussel: Amgen: Family owns Amgen stock Other, Membership on an entity's Board of Directors or advisory committees, Research Funding; Cangene: Research Funding; GlaxoSmithKline: Family owns GSK stock, Family owns GSK stock Other, Membership on an entity's Board of Directors or advisory committees, Research Funding; Genzyme: Research Funding; IgG of America: Research Funding; Immunomedics: Research Funding; Ligand: Membership on an entity's Board of Directors or advisory committees, Research Funding; Eisai: Membership on an entity's Board of Directors or advisory committees, Research Funding; Shionogi: Membership on an entity's Board of Directors or advisory committees, Research Funding; Sysmex: Research Funding; Portola: Consultancy. Off Label Use: The use of romiplostim in pediatric patients was examined in this study.

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