Eltrombopag for management of chronic immune thrombocytopenia (RAISE): a 6-month, randomised, phase 3 study

Long-term efficacy of partial splenic embolization for the treatment of steroid-resistant chronic immune thrombocytopenia

Thrombopoietin-receptor agonists have been recently introduced for a second-line treatment of immune thrombocytopenia (ITP). Splenectomy has tended to be avoided because of its complications, but the response rate of splenectomy is 60-80% and it has still been considered for steroid-refractory ITP. We performed partial splenic embolization (PSE) as an alternative to splenectomy. Between 1988 and 2013, 91 patients with steroid-resistant ITP underwent PSE at our hospital, and we retrospectively analyzed the efficacy and long-term outcomes of PSE. The complete response rate (CR, platelets > 100 × 10⁹/L) was 51% (n = 46), and the overall response rate (CR plus response (R), > 30 × 10⁹/L) was 84% (n = 76). One year after PSE, 70% of patients remained CR and R. The group with peak platelet count after PSE ≥ 300 × 10⁹/L (n = 29) exhibited a significantly higher platelet count than the group with platelet count < 300 × 10⁹/L (n = 40) at any time point after PSE. The failure-free survival (FFS) rates at 1, 5, and 10 years were 78, 56, and 52%, respectively. Second PSE was performed in 20 patients who relapsed (n = 14) or had no response to the initial PSE (n = 6), and the overall response was achieved in 63% patients. There were no PSE-related deaths. These results indicate that PSE is a safe and effective alternative therapy to splenectomy for patients with steroid-resistant ITP as it generates long-term, durable responses.

Management of newly diagnosed immune thrombocytopenia: can we change outcomes?

Immune thrombocytopenia resulting from antibody-mediated platelet destruction combined with impaired platelet production is a common cause of thrombocytopenia. The decision to treat newly diagnosed patients is based on several factors including ceasing hemorrhagic manifestations, increasing the platelet count, prevention of bleeding, and inducing remission. Current standard first-line therapy is a course of corticosteroids. Although this treatment paradigm increases the platelet count in the majority of patients, a high percentage relapse after discontinuation of corticosteroid therapy. For this reason, intensification of first-line therapy that results in superior long-term remission rates would be desirable. This manuscript focuses primarily on adults with idiopathic thrombocytopenic purpura (ITP), highlighting pediatric data and practice when applicable. The primary aim is to outline upfront strategies for treatment-naive patients with ITP to enhance remission rates, taking into account assessment of the risks and benefits of these approaches.

Effects of thrombopoietin receptor agonists on procoagulant state in patients with immune thrombocytopenia

Thrombopoietin receptor agonists (TPO-RA) have recently been introduced for the treatment of immune thrombocytopenia (ITP), an antiplatelet-antibodies autoimmune disease. The observation of a low frequency of bleeding episodes despite their thrombocytopenia suggests the existence of a compensatory mechanism. This study aimed to evaluate the effect of TPO-RA treatment on platelet function and on the procoagulant state in ITP patients before (ITP-bR) and after responding (ITP-aR) to treatment. Plasma- and microparticle (MP)-associated procoagulant capacity from ITP patients was similar before and after responding to the TPO-RA regimen but higher than the healthy control values. High MP-associated procoagulant activity did not seem to be due to increased platelet activation, since platelet stimulation by agonists was reduced in ITP-bR and ITP-aR patients. It could be related to increased platelet apoptosis, evaluated in terms of surface phosphatidylserine (PS), observed in both ITP groups. In summary, TPO-RA treatment increased platelet count but did not ameliorate their function and did not change plasma- and MP-associated procoagulant state of ITP patient responders to this therapy.

Management of newly diagnosed immune thrombocytopenia: can we change outcomes?

Immune thrombocytopenia resulting from antibody-mediated platelet destruction combined with impaired platelet production is a common cause of thrombocytopenia. The decision to treat newly diagnosed patients is based on several factors including ceasing hemorrhagic manifestations, increasing the platelet count, prevention of bleeding, and inducing remission. Current standard first-line therapy is a course of corticosteroids. Although this treatment paradigm increases the platelet count in the majority of patients, a high percentage relapse after discontinuation of corticosteroid therapy. For this reason, intensification of first-line therapy that results in superior long-term remission rates would be desirable. This manuscript focuses primarily on adults with idiopathic thrombocytopenic purpura (ITP), highlighting pediatric data and practice when applicable. The primary aim is to outline upfront strategies for treatment-naive patients with ITP to enhance remission rates, taking into account assessment of the risks and benefits of these approaches.

Efficacy of Repeated Lusutrombopag Administration for Thrombocytopenia in a Patient Scheduled for Invasive Hepatocellular Carcinoma Treatment

The efficacy of repeated lusutrombopag administration for thrombocytopenia in patients with chronic liver disease who undergo two or more planned invasive procedures is unknown. We herein report our findings regarding the effects of repeated lusutrombopag administration given to avoid platelet transfusion in a patient with chronic liver disease and thrombocytopenia. The platelet count showed a positive response to lusutrombopag treatment prior to the initial invasive procedure to treat a hepatoma, so platelet transfusion was not necessary. In conclusion, lusutrombopag may be a useful drug for patients with thrombocytopenia to avoid platelet transfusion in those undergoing two or more planned invasive procedures.

Safety and efficacy of long-term treatment of chronic/persistent ITP with eltrombopag: final results of the EXTEND study

In phase 2/3 trials, eltrombopag treatment of 6 months or less in patients with chronic/persistent immune thrombocytopenia (ITP) increased platelet counts and reduced bleeding. The open-label EXTEND study evaluated long-term safety and efficacy of eltrombopag in adults with ITP who had completed a previous eltrombopag study. For the 302 patients enrolled, median duration of eltrombopag treatment was 2.37 years (2 days-8.76 years). Median platelet counts increased to 50 × 10⁹/L or more by week 2 and were sustained throughout the treatment period. Overall, 259 patients (85.8%) achieved a response (platelet count ≥50 × 10⁹/L at least once in the absence of rescue), and 133 (52%) of 257 patients achieved a continuous response of 25 weeks or longer. Responses in patients with platelet counts lower than 15 × 10⁹/L, more previous therapies, and/or splenectomy were somewhat lower. Thirty-four (34%) of 101 patients receiving concomitant ITP medication discontinued 1 or more medication. In patients with assessments, bleeding symptoms (World Health Organization grades 1-4) decreased from 57% at baseline to 16% at 1 year. Forty-one patients (14%) withdrew because of adverse events. Hepatobiliary adverse events (n = 7), cataracts (n = 4), deep vein thrombosis (n = 3), cerebral infarction (n = 2), headache (n = 2), and myelofibrosis (n = 2) occurred in more than 1 patient; the remaining adverse events occurred only once. Rates of thromboembolic events (6%) and hepatobiliary adverse events (15%) did not increase with treatment duration past 1 year. EXTEND demonstrated that long-term use of eltrombopag was effective in maintaining platelet counts of 50 × 10⁹/L or more and reducing bleeding in most patients with ITP of more than 6 months' duration. Important adverse events (eg, thrombosis, hepatobiliary, and bone marrow fibrosis) were infrequent. (ClinicalTrials.gov:NCT00351468).

Successful eltrombopag treatment of severe refractory thrombocytopenia in chronic myelomonocytic leukemia: Two cases reports: A CARE-compliant article

RATIONALE

Thrombocytopenia in chronic myelomonocytic leukemia (CMML) is usually attributed to impaired marrow production resulting from cytotoxic drug use or CMML itself ("CMML-induced thrombocytopenia"). In very rare cases, immune thrombocytopenia (ITP) can be a complication of CMML ("CMML-associated ITP"). However, treatment of severe thrombocytopenia in patients with CMML is still a challenge.

PATIENT CONCERNS

Case 1 was a 61-year-old female patient admitted to our hospital because of skin petechiae and purpura for 6 days. She had increased monocyte cell count (1.82 × 10/L), markedly decreased platelet count (2 × 10/L), hypercellularity of the megakaryocyte lineage with many immature megakaryocytes, and ZRSR2(zinc finger CCCH-type, RNA binding motif and serine/arginine rich 2) mutation. She failed to the treatment of corticosteroids, intravenous immunoglobulin (IVIg), TPO (thrombopoietin), and cyclosporin A (CsA). Case 2 was a 72-year-old female patient with thrombocytosis and monocytosis for 4 years, and thrombocytopenia for 6 months. After 10 courses of decitabine therapy, she had a persistent severe thrombocytopenia and decreased number of megakaryocytes, TET2 (tet methylcytosine dioxygenase 2) and SRSF2 (serine and arginine rich splicing factor 2) mutations were detected. She was dependent on platelet transfusion.

DIAGNOSES

Case 1 was diagnosed as CMML-associated ITP, and case 2 as CMML with decitabine therapy-induced thrombocytopenia.

INTERVENTIONS

Both patients were treated with eltrombopag.

OUTCOMES

In both patients, the platelet counts returned to the normal within 1 week after eltrombopag therapy. The platelet count in case 1 patient remained stable at 141-200 × 10/L for 20 months with stopping therapy for 3 months. In case 2 patient, eltrombopag was stopped 1 month later. Her platelet count decreased to 41 × 10/L, but was stable at ∼30 × 10/L for 3 months with platelet transfusion independency for 12 months. Both patients had no adverse effects with eltrombopag.

LESSONS

CMML-associated ITP is very rare and easily misdiagnosed. To the best of our knowledge, case 1 is the first reported case of the successful treatment of CMML-associated ITP with eltrombopag. Both CMML-associated ITP and decitabine therapy-induced thrombocytopenia in these 2 patients were highly sensitive and safe to eltrombopag therapy.

Eltrombopag for secondary failure of platelet recovery post-allogeneic hematopoietic stem cell transplant in children

Secondary failure of platelet engraftment occurs in 20% of patients undergoing allogeneic HSCT and is associated with poor outcome. Currently, there are no guidelines for treatment of late thrombocytopenia and platelet transfusion is the mainstay of treatment. Here, we describe the use of Eltrombopag to treat secondary failure of platelet recovery following HSCT in a child with severe aplastic anemia. Eltrombopag resulted in recovery of platelet count with no need for platelet transfusion support with no reported side effects. Eltrombopag may be used successfully in children with secondary failure of platelet recovery post-HSCT for SAA.

Eltrombopag: a powerful chelator of cellular or extracellular iron(III) alone or combined with a second chelator

Eltrombopag (ELT) is a thrombopoietin receptor agonist reported to decrease labile iron in leukemia cells. Here we examine the previously undescribed iron(III)-coordinating and cellular iron-mobilizing properties of ELT. We find a high binding constant for iron(III) (log β₂=35). Clinically achievable concentrations (1 µM) progressively mobilized cellular iron from hepatocyte, cardiomyocyte, and pancreatic cell lines, rapidly decreasing intracellular reactive oxygen species (ROS) and also restoring insulin secretion in pancreatic cells. Decrements in cellular ferritin paralleled total cellular iron removal, particularly in hepatocytes. Iron mobilization from cardiomyocytes exceeded that obtained with deferiprone, desferrioxamine, or deferasirox at similar iron-binding equivalents. When combined with these chelators, ELT enhanced cellular iron mobilization more than additive (synergistic) with deferasirox. Iron-binding speciation plots are consistent with ELT donating iron to deferasirox at clinically relevant concentrations. ELT scavenges iron citrate species faster than deferasirox, but rapidly donates the chelated iron to deferasirox, consistent with a shuttling mechanism. Shuttling is also suggested by enhanced cellular iron mobilization by ELT when combined with the otherwise ineffective extracellular hydroxypyridinone chelator, CP40. We conclude that ELT is a powerful iron chelator that decreases cellular iron and further enhances iron mobilization when combined with clinically available chelators.

Patterns of care and burden of chronic idiopathic thrombocytopenic purpura in Brazil

AIMS

Although several therapeutic options are available for chronic immune thrombocytopenic purpura (cITP), little is known about the treatment of cITP in Brazil.

MATERIALS AND METHODS

A multi-center, retrospective chart review, observational study was designed to describe the treatment patterns, clinical burden, resources use, and associated costs for adult patients diagnosed with cITP and treated in public and private institutions in Brazil. Patient charts were screened in reverse chronological order based on their last visit post January 1, 2012. (All costs were calculated using 1.00 USD = 3.9571 BRL, from February 2016.) Results: Of 340 patient charts screened, 50 patients were eligible for inclusion in the study. Single-drug therapy (prednisone, dexamethasone, or dapsone) was the most commonly used treatment, followed by combination therapies (azathioprine + prednisone, azathioprine + prednisone + danazol, and prednisone + dapsone). Splenectomy was performed in 22% of patients after at least first-line treatment. Platelet count and number of bleeding episodes at diagnosis were 31,561.1/mm³ (SD = ±26,396.1) and 40 episodes, respectively; in first-line, 92,631.1/mm³ (SD = ±79,955.3) and 19 episodes, respectively; in second-line, 96,950.0/mm³ (SD = ±76,476.4) and 17 episodes, respectively. Private system patients had a higher median cost compared to public system patients (USD 17.49/month, range = 0-2,020.77 vs USD 9.51/month, range = 0-192.64, respectively).

LIMITATIONS

This study does not allow conclusions for causal explanations due to the cohort study design, and treatment patterns represent only the practices of physicians who have agreed to participate in the study.

CONCLUSIONS

The data indicate that available therapeutic strategies for second- and third-line therapies appear to be limited.

Safety, Pharmacokinetics and Pharmacodynamics of Hetrombopag Olamine, a Novel TPO-R Agonist, in Healthy Individuals

Hetrombopag olamine (hetrombopag) is a novel small-molecule, orally bioavailable, non-peptide thrombopoietin (TPO) receptor agonist that is being developed as the treatment for thrombocytopenia. Two randomized, placebo-controlled phase I studies were conducted in 72 healthy individuals to assess the safety, tolerability, pharmacokinetics and pharmacodynamics of hetrombopag. Hetrombopag was orally administered with a single dose in five dose cohorts (5 mg, 10 mg, 20 mg, 30 mg or 40 mg) in the first study, and given once daily for 10 days in three dose cohorts (2.5 mg, 5.0 mg or 7.5 mg) in the second study, respectively. Hetrombopag was well tolerated, and the majority of adverse events associated with medicine were platelet elevations significantly above the normal range in healthy individuals. The single dose-escalation study revealed a T_max of approximate 8 hr, and a t_1/2 of 11.9 hr to 40.1 hr in a dose-prolonged manner. A dose-proportional increase in maximum concentration (C_max ) of hetrombopag was observed, with area under the curve (AUC) increasing in a greater than dose-proportional manner. The plasma concentration of hetrombopag reached the steady-state after 7 days. The steady-state AUC_0-24 hr and C_max were dose-proportionally elevated from the 5.0 mg to 7.5 mg dose level. The potent pharmacological effect of the hetrombopag-induced platelet elevation was observed in a time- and dose-dependent manner. Furthermore, the thrombopoietic response was significantly (p < 0.0001) correlated to the plasma exposure level of hetrombopag in single and multiple administration studies. Taken together, results of this study support further clinical development of hetrombopag in patients with thrombocytopenia.

Use of eltrombopag for secondary immune thrombocytopenia in clinical practice

Eltrombopag is a second-line treatment in primary immune thrombocytopenia (ITP). However, its role in secondary ITP is unknown. We evaluated the efficacy and safety of eltrombopag in secondary ITP in daily clinical practice. Eighty-seven secondary ITP patients (46 with ITP secondary to autoimmune syndromes, 23 with ITP secondary to a neoplastic disease subtype: lymphoproliferative disorders [LPDs] and 18 with ITP secondary to viral infections) who had been treated with eltrombopag were retrospectively evaluated. Forty-four patients (38%) had a platelet response, including 40 (35%) with complete responses. Median time to platelet response was 15 days (95% confidence interval, 7-28 days), and was longer in the LPD-ITP group. Platelet response rate was significantly lower in the LPD-ITP than in other groups. However, having achieved response, there were no significant differences between the durable response of the groups. Forty-three patients (49·4%) experienced adverse events (mainly grade 1-2), the commonest being hepatobiliary laboratory abnormalities. There were 10 deaths in this case series, all of which were related to pre-existing medical conditions. In routine clinical practice, eltrombopag is effective and well-tolerated in unselected patients with ITP secondary to both immune and infectious disorders. However, the response rate in LPD-ITP is low.

Thrombopoetin receptor agonist therapy in thrombocytopenia: ITP and beyond

Eltrombopag is well established in treatment of severe immune thrombocytopenia (ITP) and is increasingly commonplace in second-line management. A role is also suggested for both bridging therapy for surgery, as well as treating thrombocytopenia due to non-immune aetiologies. We present the largest single-centre experience with eltrombopag, with our cohort of 62 patients. Patients with severe ITP (n = 34) had 91·2% response, which was sustained over a median of 18·5 months. In 41·4% of ITP cases (n = 14), complete response (CR- platelet count >100 × 10⁹ /l) was achieved and in 2 cases, therapy was stopped and CR maintained. In our bridging group (n = 15) with a higher baseline platelet count, 93·3% achieved a CR. In the non-ITP group (n = 13), a response was achieved in 76·9%. In all groups, side effects were transient, with the drug discontinued in 2 patients due to minor complications (rash, nausea, diarrhoea). We conclude that eltrombopag is both effective and well tolerated as therapy in severe ITP. It is also advantageous in ITP patients who do not normally require therapy, but need a temporary platelet count boost pre-procedure. Furthermore, there are potentially far wider implications for the use of eltrombopag in counteracting thrombocytopenia beyond ITP, which merit further investigation.

Beyond immune thrombocytopenia: the evolving role of thrombopoietin receptor agonists

Since its discovery, the thrombopoietin (TPO) pathway has been an important pharmaceutical target for the treatment of thrombocytopenia. The first generation of TPO mimetics included peptide agents sharing homology with endogenous TPO, but these introduced a risk of antibody formation to endogenous TPO and were not successful. However, second-generation TPO mimetics or TPO receptor agonists (RAs) are currently being used to treat thrombocytopenia associated with a number of conditions, such as immune thrombocytopenia (ITP), severe aplastic anaemia (SAA), and hepatitis C virus-associated chronic liver disease. Accumulating efficacy and safety data suggest that the role of TPO-RAs in the treatment of thrombocytopenia may evolve in the near future with broader use of these agents in ITP and SAA, as well as approval in other indications, potentially including myelodysplastic syndromes, chemotherapy-associated thrombocytopenia, and post-transplant thrombocytopenia. This review provides an overview of clinical data on the efficacy and safety of TPO-RAs, emphasising recent findings that may expand their clinical utility.

A practical guide to the use of eltrombopag in children with chronic immune thrombocytopenia

INTRODUCTION

Pediatric immune thrombocytopenia (ITP) may be associated with significant burden on children and their parents/caregivers. Thrombopoietin (TPO) receptor agonists (RAs) have been used to treat adult patients with chronic ITP (cITP) for nearly a decade and following pediatric studies Eltrombopag has been recently approved for pediatric cITP in the United States and Europe. TPO-RA s may help reduce the risk of bleeding and the need for conventional ITP therapies.

REVIEW

In this review, the clinical data demonstrating the efficacy and safety of TPO-RAs in pediatric ITP are evaluated, key recommendations regarding safe administration of eltrombopag are provided, and potential future directions in management of pediatric ITP are discussed.

The Efficacy of Colchicine and Dapsone Combination Therapy in Relapsed Immune Thrombocytopenia

The aim of the present paper is to evaluate the efficacy and safety of colchicine and dapsone combination therapy in cases of steroid-dependent, relapsed and refractory immune thrombocytopenia (ITP). This is a retrospective study of ITP patients who attended the Hematology Clinic at Chiang Mai University Hospital (Thailand) from 1 January 2008 to 30 September 2014. Medical records and clinical data were reviewed for efficacy and adverse effects. Sixty-four ITP patients received the combination therapy. The median age was 46 years and 70.3% were female. The majority (65.6%) were relapsed ITP patients. Median platelet count before starting treatment was 22.6×10⁹/L. The response rate was 82.8%, with 75.0% of patients having a complete response. Median time to response was 8 weeks. The response rate was higher in relapsed patients (90.4%) compared to refractory (61.5%) and steroid-dependent patients (77.8%). Steroid treatment was discontinued in 30 patients (50%) following combination therapy. The most common side effect was hemolysis due to dapsone which was found in eight patients (12.5%). We can therefore conclude that combination therapy with colchicine and dapsone is an alternative second-line therapy option in relapsed ITP cases with acceptable side effects.

From chronic immune thrombocytopenia to severe aplastic anemia: recent insights into the evolution of eltrombopag

Thrombopoietin (TPO) is the most potent cytokine stimulating thrombopoiesis. Therapy with exogenous TPO is limited by the formation of antibodies cross-reacting with endogenous TPO. Mimetics of TPO are compounds with no antigenic similarity to TPO. Eltrombopag is an orally-active nonpeptide small molecule that binds to the transmembrane portion of the TPO receptor MPL. Initial trials of eltrombopag have centered on immune thrombocytopenia (ITP), which is due to both increased destruction and decreased production of platelets. Eltrombopag at 25-75 mg/day has been shown to be highly effective in raising the platelet count in ITP with suboptimal response to immunosuppression and splenectomy. These successful results led to the exploration of eltrombopag in other thrombocytopenic disorders. In hepatitis C viral infection, eltrombopag raises the platelet count sufficiently enough to allow treatment with ribavirin and pegylated interferon. Because MPL is expressed on hematopoietic cells, eltrombopag use in myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) might enhance leukemic proliferation. Clinical trials of eltrombopag in MDS and AML, however, have shown amelioration of thrombocytopenia without promoting disease progression. In severe aplastic anemia (SAA) not responding to immunosuppression with anti-thymocyte globulin (ATG) and cyclosporine, eltrombopag as a single agent at 150-300 mg/day results in an overall response rate of 40-70%. At high doses, adverse effects including pigmentation, gastrointestinal upset and hepatic derangement have become evident. Current studies have examined the first-line use of eltrombopag in combination with ATG in SAA. In a recent study, eltrombopag used at 150 mg/day with horse ATG resulted in an overall response rate of 90% in newly diagnosed SAA patients, with a complete response rate of about 50%. Clonal karyotypic aberrations are, however, found in 10-20% of SAA patients treated with eltrombopag. The safety and efficacy of eltrombopag in SAA require further evaluation, particularly when it is used with less intensive immunosuppression.

Bidirectional inefficacy or intolerability of thrombopoietin receptor agonists: new data and a concise review

BACKGROUND

There is evidence that the thrombopoietin-receptor agonists romiplostim and eltrombopag may have different therapeutic values and adverse reaction profiles. Here we present new data and provide a review of all studies dealing with switching between these two drugs.

MATERIALS AND METHODS

A total of 89 patients (38 males and 51 females, aged between 14-87 years) were treated with eltrombopag and/or romiplostim between 2007 and 2016 at our institution. Eltrombopag was switched to romiplostim or vice versa in 32 patients. In addition, all published data concerning patients treated sequentially with different thrombopoietin-receptor agonists were identified via a computer-assisted search and summarised in this article.

RESULTS

Thirty-two of 89 patients treated with a thrombopoietin-receptor agonist in our institution were given both eltrombopag and romiplostim sequentially. Therapy was switched to the alternate thrombopoietin-receptor agonist 36 times, due to inefficacy (n=21), adverse reactions (n=14), and a patient's preference (n=1). In addition, data from 126 patients who have been treated with both agonists have been published by other groups. In total eltrombopag was replaced by romiplostim in 56 cases due to poor or no response or to adverse reactions. Forty-five patients responded to treatment with romiplostim, 11 patients shared cross-resistance and nine had adverse reactions to romiplostim. In contrast, romiplostim was replaced by eltrombopag in 106 cases. Seventy-eight patients responded to eltrombopag, 27 shared cross-resistance and 19 had adverse reactions to eltrombopag.

DISCUSSION

Eltrombopag and romiplostim often share bidirectional cross-resistance and/or adverse reactions. Both drugs appear to cause more adverse reactions than have been previously reported.

A 2-Year, Longitudinal, Prospective Study of the Effects of Eltrombopag on Bone Marrow in Patients with Chronic Immune Thrombocytopenia

BACKGROUND

The long-term effects of eltrombopag on bone marrow (BM) reticulin and/or collagen deposition in previously treated adults with chronic immune thrombocytopenia (ITP) were assessed.

METHODS

Three BM biopsies were collected at baseline and after 1 and 2 years of eltrombopag treatment. Specimens were centrally processed, stained for reticulin and collagen, independently reviewed by 2 hematopathologists, and rated according to the European Consensus 0-3 scale of marrow fibrosis (MF).

RESULTS

Of 162 patients enrolled, 93 completed all 3 protocol-specified BM biopsies. All patients with a baseline assessment were negative for collagen. Of 159 patients assessed at baseline, 150 (94%) had normal reticulin (MF-0) and 9 (6%) had minimally increased reticulin (MF-1). After 2 years, 83/93 patients (89%) with BM biopsies had MF-0, 10 (11%) had MF-1, and none had MF-2 or MF-3. Five out of 127 patients (4%) at 1 year and 1 out of 93 (1%) at 2 years had collagen deposition. None of the patients had clinical symptoms typical of BM dysfunction or abnormalities of clinical concern based on white blood cell count or peripheral blood smear.

CONCLUSION

For most patients with chronic ITP, eltrombopag is not associated with clinically relevant increases in BM reticulin or collagen formation.

Efficacy and safety of thrombopoietin receptor agonists in patients with primary immune thrombocytopenia: A systematic review and meta-analysis

Immune thrombocytopenia (ITP) is an autoimmune disease characterized by increased platelet destruction and impaired platelet production. In this study, we conducted a systematic review and meta-analysis to determine the efficacy and safety of thrombopoietin receptor agonists (TPO-RAs) in primary ITP patients. Thirteen randomized controlled trials were included in this study, the pooled results of which demonstrated that TPO-RAs significantly increased platelet response (R) and durable response (DR) rates [risk ratio (RR): 2.77, 95% confidence interval (CI): 2.01-3.82, P = 5.9 × 10-10; RR: 7.52, 95% CI: 3.94-14.35, P = 9.2 × 10-10; respectively] and that TPO-RAs significantly reduced the incidences of any or severe bleeding events (RR: 0.80, 95% CI: 0.67-0.95, P = 0.013; RR: 0.52, 95% CI: 0.27-0.99, P = 0.048; respectively). Moreover, our results indicated that there was a significant reduction in the proportion of patients needing rescue medications in the TPO-RA groups compared with the control groups (RR: 0.50, 95% CI: 0.42-0.59, P = 2.0 × 10-15) and that the rates of any or severe adverse events were similar between the TPO-RA and control regimens (RR: 1.01, 95% CI: 0.92-1.10; RR: 0.74, 95% CI: 0.54-1.01; respectively). These findings demonstrate that TPO-RAs are an effective and safe second-line treatment option for primary ITP patients.

Second-line therapies in immune thrombocytopenia

Immune thrombocytopenia (ITP) is a rare, acquired autoimmune condition characterized by a low platelet count and an increased risk of bleeding. Although many children and adults with ITP will not need therapy beyond historic first-line treatments of observation, steroids, intravenous immunoglobulin (IVIG), and anti-D globulin, others will have an indication for second-line treatment. Selecting a second-line therapy depends on the reason for treatment, which can vary from bleeding to implications for health-related quality of life (HRQoL) to likelihood of remission and patient preference with regard to adverse effects, route of administration, and cost. Published studies of these treatments are limited by lack of comparative trials, in addition to inconsistent outcome measures, definitions, and efficacy endpoints. This article provides an up-to-date comparison of the second-line treatments, highlighting important outcome measures including bleeding, HRQoL, fatigue, and platelet counts, which influence treatment selection in a shared decision-making model.

Successful use of eltrombopag in a child with refractory immune thrombocytopenia: case study and literature review

Treatment of refractory immune thrombocytopenia (ITP) continues to challenge medical practitioners because of the lack of well tolerated and effective drugs. Eltrombopag is a second-generation thrombopoietin approved to treat adult chronic/refractory ITP in 2008. The use of eltrombopag to treat pediatric refractory ITP remains in the clinical trial stage, and no reports on its use in China are yet available. In this article, we describe a pediatric case of refractory ITP that was successfully treated with eltrombopag. Eltrombopag appears to be well tolerated and effective for treating pediatric refractory ITP with few side-effects.

Efficacy and safety of eltrombopag in treatment-refractory primary immune thrombocytopenia: a retrospective study

Eltrombopag was used in patients with chronic primary immune thrombocytopenia (ITP) who did not tolerate or were refractory to two or more previous treatments. The primary aims of the study were to determine the efficacy and safety of long-term eltrombopag treatment. Data were extracted from medical chart records retrospectively. Platelet count of at least 50 000/μl at any time point during the treatment was defined as the 'response'. Median duration of eltrombopag treatment was 29 weeks (11-74). The number of patients who had a platelet count of at least 50 000/μl at any time point was 26 (83.9%). The response was achieved by the second week in most of the patients. Concomitant ITP medications were withdrawn in nine out of the 11 patients. Eltrombopag was discontinued in one patient due to sustained response despite discontinuation of the treatment. Age, sex, concomitant ITP treatments, and previous ITP treatment failures had no impact on the treatment response. The treatment was discontinued due to thrombosis in only four patients. Four patients experienced a minor bleeding event. Hepatotoxicity and all other adverse events were mild and manageable. Eltrombopag is effective, safe, and well tolerated in the long-term treatment of chronic ITP patients.

How I treat refractory immune thrombocytopenia

This article summarizes our approach to the management of children and adults with primary immune thrombocytopenia (ITP) who do not respond to, cannot tolerate, or are unwilling to undergo splenectomy. We begin with a critical reassessment of the diagnosis and a deliberate attempt to exclude nonautoimmune causes of thrombocytopenia and secondary ITP. For patients in whom the diagnosis is affirmed, we consider observation without treatment. Observation is appropriate for most asymptomatic patients with a platelet count of 20 to 30 × 109/L or higher. We use a tiered approach to treat patients who require therapy to increase the platelet count. Tier 1 options (rituximab, thrombopoietin receptor agonists, low-dose corticosteroids) have a relatively favorable therapeutic index. We exhaust all Tier 1 options before proceeding to Tier 2, which comprises a host of immunosuppressive agents with relatively lower response rates and/or greater toxicity. We often prescribe Tier 2 drugs not alone but in combination with a Tier 1 or a second Tier 2 drug with a different mechanism of action. We reserve Tier 3 strategies, which are of uncertain benefit and/or high toxicity with little supporting evidence, for the rare patient with serious bleeding who does not respond to Tier 1 and Tier 2 therapies.

Eltrombopag for the treatment of aplastic anemia: current perspectives

Aplastic anemia (AA) is a potential life-threatening hematopoietic stem cell (HSC) disorder resulting in cytopenia. The mainstays of treatment for AA are definitive therapy to restore HSCs and supportive measures to ameliorate cytopenia-related complications. The standard definitive therapy is HSC transplantation for young and medically fit patients with suitable donors and immunosuppressive therapy (IST) with antithymocyte globulin and cyclosporine for the remaining patients. A significant proportion of patients are refractory to IST or relapse after IST. Various strategies have been explored in these patients, including second course of antithymocyte globulin, high-dose cyclophosphamide, and alemtuzumab. Eltrombopag, a thrombopoietin mimetic, has recently emerged as an encouraging and promising agent for patients with refractory AA. It has demonstrated efficacy in restoring trilineage hematopoiesis, and this positive effect continues after discontinuation of the drug. There are ongoing clinical trials exploring the role of eltrombopag as a first-line therapy in moderate to severe AA and a combination of eltrombopag with IST in severe AA.

Signal for Thrombosis with Eltrombopag and Romiplostim: A Disproportionality Analysis of Spontaneous Reports Within VigiBase®

INTRODUCTION

Eltrombopag and romiplostim are thrombopoietin receptor agonists (TPO-RAs) marketed for immune thrombocytopenia (ITP). Thrombotic events have been reported with both drugs. This study was aimed at assessing whether there is a signal for differential risks of thrombosis between these two TPO-RAs.

METHODS

We carried out a disproportionality analysis in the World Health Organization global individual case safety report (ICSR) database (VigiBase(®)). We selected all ICSRs with exposure to a TPO-RA between January 2011 and December 2014. We searched for exposures to eltrombopag or romiplostim in thrombosis reports as compared with other ICSRs, and we calculated adjusted reporting odds ratios (aRORs).

RESULTS

We identified 5850 ICSRs, including 764 cases of thrombosis. In multivariate analyses, there was a signal for an increased risk of thrombosis (venous or arterial; aROR 1.72, 95 % confidence interval [CI] 1.47-2.02), venous thrombosis (aROR 1.88, 95 % CI 1.53-2.31), arterial thrombosis (aROR 1.54, 95 % CI 1.18-2.00), ischaemic stroke (aROR 1.65, 95 % CI 1.13-2.42) and myocardial infarction (aROR 1.50, 95 % CI 1.05-2.13) with eltrombopag as compared with romiplostim. Restriction to ICSRs reported by physicians led to similar results. However, worldwide dispensing data for romiplostim and eltrombopag were not accessible, so the rates of thrombosis with both drugs were not normalized by the daily defined doses and the generalizability of the results is limited.

CONCLUSION

This study suggests the presence of a signal for an increased risk of thrombosis with eltrombopag compared with romiplostim. These results must be confirmed and quantified by large aetiological pharmacoepidemiological studies.

Tolerability and Efficacy of Eltrombopag in Chronic Immune Thrombocytopenia: Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Eltrombopag is an oral thrombopoietin receptor agonist that stimulates the production of normally functioning platelets. The aim of this meta-analysis is to synthesize evidence about the safety and efficacy of eltrombopag for both adult and children with primary immune thrombocytopenia (ITP).

METHODS

A computer literature search of PubMed, Scopus, Web of Science, and Cochrane Central was conducted. Records were screened for eligible studies, and data were extracted and synthesized using Review Manager for Windows. Subgroup analysis and sensitivity analysis were conducted to investigate whether treatment effect varies significantly between adults and children.

RESULTS

Six randomized controlled trials (N = 611 patients) were included in the final analysis. The overall effect estimates favored eltrombopag group in terms of overall platelet response (relative risk [RR]: 3.42; 95% confidence interval [CI]: 2.51-4.65; P < .0001), incidence of significant bleeding (RR: 0.56; 95% CI: 0.41-0.77; P = .0004), and number of cases needed to rescue treatment (RR: 0.45; 95% CI: 0.32-0.65; P < .0001). The efficacy of eltrombopag did not differ significantly between children and adults except for incidence of any bleeding (RR: 0.83 vs 0.51; P = .008).

CONCLUSION

Eltrombopag is a tolerable and effective drug for the management of chronic ITP in children and adults.

Thrombopoietin Receptor Agonist Use in Children: Data From the Pediatric ITP Consortium of North America ICON2 Study

BACKGROUND

Data on second-line treatment options for pediatric patients with immune thrombocytopenia (ITP) are limited. Thrombopoietin receptor agonists (TPO-RA) provide a nonimmunosuppressive option for children who require an increased platelet count.

PROCEDURE

We performed a multicenter retrospective study of pediatric ITP patients followed at ITP Consortium of North America (ICON) sites to characterize TPO-RA use.

RESULTS

Seventy-nine children had a total of 87 treatments (28 eltrombopag, 43 romiplostim, and eight trialed on both). The majority had primary ITP (82%) and most (60.8%) had chronic ITP. However, 22% had persistent ITP and 18% had newly diagnosed ITP. During the first 3 months of treatment, 89% achieved a platelet count ≥ 50 × 10(9) /l (86% romiplostim, 81% eltrombopag, P = 0.26) at least once in the absence of rescue therapy. The average time to a response was 6.4 weeks for romiplostim and 7.0 weeks for eltrombopag (P = 0.83). Only 40% of patients demonstrated a stable response with consistent dosing over time. An intermittent response with constant dose titration was seen in 15%, and an initial response that waned to no response was seen in 13%. Significant adverse events were minimal with the exception of two patients with thrombotic events and one who developed a neutralizing antibody.

CONCLUSIONS

Our results demonstrate that TPO-RA agents are being used in children with ITP of varying duration and severity. The response was similar to clinical trials, but the sustainability of response varied. Future studies need to focus on the ideal timing and rationale for these medications in pediatric patients.

Thrombopoietin Receptor Agonists Are Often Ineffective in Immune Thrombocytopenia and/or Cause Adverse Reactions: Results from One Hand

BACKGROUND

Eltrombopag and romiplostim are thrombopoietin receptor agonists (TPOs) that have been increasingly used for the treatment of immune thrombocytopenia (ITP). Based on our experience, the incidence of abortive treatment with these drugs and the occurrence of adverse reactions that lead to therapy break-off despite response are higher than has been previously suggested.

METHODS

During the last 8 years, a total of 65 patients were treated with eltrombopag and/or romiplostim at our institute.

RESULTS

36 of a total of 58 patients responded well to eltrombopag. In 12 patients that responded, treatment with eltrombopag was discontinued due to the development of adverse reactions. Eltrombopag was replaced by romiplostim in 23 cases (14 non-responders, 9 patients with adverse reactions). Of these patients, 83% responded to romiplostim. Among all patients treated with romiplostim (n = 32), 75% initially responded; however, 8 of these patients developed adverse reactions. Romiplostim was replaced by eltrombopag in 5 cases (4 due to adverse reactions, 1 non-responsive patient), and only 3 (60%) of these patients were observed to respond to eltrombopag.

CONCLUSION

TPOs often remain ineffective in ITP or result in adverse reactions, which lead to treatment stop or to drug switch. Therefore, alternative treatment options are required.

Advances in Diagnosis and Treatments for Immune Thrombocytopenia

Immune thrombocytopenia (ITP) is an acquired hemorrhagic condition characterized by the accelerated clearance of platelets caused by antiplatelet autoantibodies. A platelet count in peripheral blood <100 × 10⁹/L is the most important criterion for the diagnosis of ITP. However, the platelet count is not the sole diagnostic criterion, and the diagnosis of ITP is dependent on additional findings. ITP can be classified into three types, namely, acute, subchronic, and persistent, based on disease duration. Conventional therapy includes corticosteroids, intravenous immunoglobulin, splenectomy, and watch-and-wait. Second-line treatments for ITP include immunosuppressive therapy [eg, anti-CD20 (rituximab)], with international guidelines, including rituximab as a second-line option. The most recently licensed drugs for ITP are the thrombopoietin receptor agonists (TRAs), such as romiplostim and eltrombopag. TRAs are associated with increased platelet counts and reductions in the number of bleeding events. TRAs are usually considered safe, effective treatments for patients with chronic ITP at risk of bleeding after failure of first-line therapies. Due to the high costs of TRAs, however, it is unclear if patients prefer these agents. In addition, some new agents are under development now. This manuscript summarizes the pathophysiology, diagnosis, and treatment of ITP. The goal of all treatment strategies for ITP is to achieve a platelet count that is associated with adequate hemostasis, rather than a normal platelet count. The decision to treat should be based on the bleeding severity, bleeding risk, activity level, likely side effects of treatment, and patient preferences.

Cost-Effectiveness of Eltrombopag versus Romiplostim for the Treatment of Chronic Immune Thrombocytopenia in England and Wales

OBJECTIVES

To evaluate the cost-effectiveness of eltrombopag compared with romiplostim to be used in the treatment of chronic immune thrombocytopenia in patients in England and Wales who are splenectomized or ineligible for splenectomy and are refractory to other treatments.

METHODS

A Markov cohort model in which patients were administered a sequence of treatments was used to predict long-term outcomes associated with each treatment. The model was informed by data from the eltrombopag clinical trial program and the available literature. The analysis was conducted from the perspective of the UK National Health Service, and a lifetime time horizon was used. Deterministic and probabilistic sensitivity analyses were performed.

RESULTS

Eltrombopag dominated romiplostim (i.e., eltrombopag was as effective as but less costly than romiplostim) in both splenectomized and nonsplenectomized patients, assuming a class effect for the two treatments. Eltrombopag also dominated romiplostim in most deterministic sensitivity analyses with the exception of when indirect efficacy estimates were incorporated into the model. In this analysis, eltrombopag no longer dominated romiplostim but remained cost-effective versus romiplostim at a willingness-to-pay threshold of £20,000 per quality-adjusted life-year. Probabilistic sensitivity analysis demonstrated that there was a 99% and 92% chance of eltrombopag being cost-effective at a cost-effectiveness threshold of £20,000 per quality-adjusted life-year in splenectomized and nonsplenectomized patients, respectively.

CONCLUSIONS

Results of this study demonstrate that eltrombopag is cost-effective when compared with romiplostim to be used in the treatment of chronic immune thrombocytopenia, representing good value for the UK National Health Service.

A Phase 3, Randomized, Double-Blind, Placebo-Controlled Study to Determine the Effect of Romiplostim on Health-Related Quality of Life in Children with Primary Immune Thrombocytopenia and Associated Burden in Their Parents

BACKGROUND

Chronic immune thrombocytopenia (ITP) in children can negatively impact their health-related quality of life (HRQoL) and impose a burden on their parents. This study sought to examine the effect of romiplostim on HRQoL and parental burden in children with primary ITP.

PROCEDURE

This was a phase 3, randomized, double-blind, placebo-controlled study. Children aged <18 years with ITP ≥6 months were randomly assigned to receive romiplostim or placebo for 24 weeks. The Kids' ITP Tool (KIT) was used to measure HRQoL and was administered to patients and/or their parents at baseline and weeks 8, 16, and 25. Mean KIT scores at each assessment and mean changes in KIT scores from baseline were calculated overall by treatment group and platelet response status. Psychometric properties of the KIT were evaluated and the minimally important difference (MID) was estimated for different KIT versions.

RESULTS

Sixty-two patients (42 romiplostim and 20 placebo) were enrolled. Changes in KIT scores by treatment group showed numerically greater and more often statistically significant improvements from baseline to each assessment for children receiving romiplostim versus placebo. Mixed-effects analysis demonstrated statistically significantly greater reduction in parental burden from baseline in the romiplostim group versus placebo. Ranges for the MID were estimated as 9-13 points for the Child Self-Report version and 11-13 points for the Parent Impact version.

CONCLUSIONS

The treatment with romiplostim may be associated with improved HRQoL in children with primary ITP and reduced burden to their parents.

Factors associated with the effect of open splenectomy for immune thrombocytopenic purpura

OBJECTIVE

To assess the effect and complications of open splenectomy (OS) for immune thrombocytopenic purpura (ITP) and determine preoperative factors associated with surgical effect.

METHODS

This was a retrospective analysis of ITP patients who failed medical therapy and were treated with OS between 1997 and 2014 at the Jinshan Hospital, China. Follow-up was 60 months. Surgical effect was determined from platelet counts and bleeding episodes. Complications were assessed including bleeding episodes. Preoperative factors were identified by logistic regression analysis.

RESULTS

Fifty-six patients (48.2 ± 16.2 yr old; 39 females) were included. Disease course was 31.2 ± 48.2 months; 91.1% patients had preoperative platelet count <20 × 10⁹ /L. OS effect at 1 wk, 1 month, 1 yr, and 5 yrs was in 91.1%, 92.9%, 91.1%, and 89.3% patients, respectively. Pneumonia or lower extremity thrombosis occurred in 7.1% patients. Postoperative mild, moderate, and severe bleeding occurred in 33.9%, 50.0%, and 16.1% patients, respectively. No patients required blood transfusion. Mortality was zero. Larger spleen size associated with surgical effect at 1 wk, 1 month, and 1 yr, and lower preoperative minimum platelet count associated with effect at 5 yrs (P < 0.05).

CONCLUSIONS

Open splenectomy is an effective treatment with less complications for the management of ITP. Lower preoperative minimum platelet count associated with successful OS at 5 yrs.

Have splenectomy rate and main outcomes of ITP changed after the introduction of new treatments? A monocentric study in the outpatient setting during 35 years

In the last years, rituximab (RTX) and agonists of the thrombopoietin receptor (TPO-R) eltrombopag and romiplostim have provided new treatment options in persistent and chronic immune thrombocytopenia (ITP). Here, we analyzed the changes in therapeutic choices over time and their impact on clinical outcomes in a cohort of 557 ITP outpatients followed at the "L. and A. Seràgnoli" Institute of Hematology, Bologna, Italy, from 1980 to 2015. Overall 397 patients (71%) required front-line corticosteroids, mainly prednisone. Over the decades, splenectomy was delayed from second to third-line, but was steadily used in around 15-25% of patients refractory or relapsing after first-line treatment. Consensually, RTX and TPO-R agonists emerged as second and third-line therapy of choice, respectively. Splenectomy was associated with the best response rates and the lower incidences of relapse, while the relapse rate after RTX was comparable to that observed with corticosteroids and other immunosuppressive agents. The introduction of TPO-R agonists gave an alternative to the administration of immunosuppressive drugs and probably contributed to moderate the incidence of infectious complications that remained stable over the decades, despite an increasing use of RTX from the 2000s onwards. Overall responses were similar over time, with over 97% achieving a response in all time-periods. However, the cumulative risk of bleeding significantly decreased [14.3% (1980-89) vs. 7% (1990-99) vs. 5.6% (2000-09) vs. 0.2% (2010-15)] (P < 0.001), mainly thanks to the optimization of front-line corticosteroids therapy and to the wider availability of second and third-line therapies.

Bone marrow niche in immune thrombocytopenia: a focus on megakaryopoiesis

Immune thrombocytopenia (ITP) is an autoimmune disorder characterized by increased bleeding tendency and thrombocytopenia. In fact, the precise pathogenesis of this disease is still not clear. Megakaryopoiesis involves complete differentiation of megakaryocyte (MK) progenitors to functional platelets. This complex process occurs in specific bone marrow (BM) niches composed of several hematopoietic and non-hematopoietic cell types, soluble factors, and extracellular matrix proteins. These specialized microenvironments sustain MK maturation and localization to sinusoids as well as platelet release into circulation. However, MKs in ITP patients show impaired maturation and signs of degradation. Intrinsic defects in MKs and their extrinsic environment have been implicated in altered megakaryopoiesis in this disease. In particular, aberrant expression of miRNAs directing MK proliferation, differentiation, and platelet production; defective MK apoptosis; and reduced proliferation and differentiation rate of the MSC compartment observed in these patients may account for BM defects in ITP. Furthermore, insufficient production of thrombopoietin is another likely reason for ITP development. Therefore, identifying the signaling pathways and transcription factors influencing the interaction between MKs and BM niche in ITP patients will contribute to increased platelet production in order to prevent incomplete MK maturation and destruction as well as BM fibrosis and apoptosis in ITP. In this review, we will examine the interaction and role of BM niches in orchestrating megakaryopoiesis in ITP patients and discuss how these factors can be exploited to improve the quality of patient treatment and prognosis.