Romiplostim for the treatment of chronic immune thrombocytopenia in adult Japanese patients: a double-blind, randomized Phase III clinical trial

The efficacy and safety of romiplostim, a thrombopoietin-mimetic peptibody, were evaluated in a double-blind, placebo-controlled, randomized trial of Japanese patients with chronic immune thrombocytopenia (ITP). Thirty-four ITP patients received romiplostim (n?=?22) or placebo (n?=?12) for 12?weeks, with a starting romiplostim dose of 3?μg/kg weekly. The primary end point was the number of weeks with platelet response, defined as a platelet count ≥50?×?10(9)/L (not including the 4?weeks after rescue medication administration). Patients received a median of 4 (range 1-19) prior ITP therapies including splenectomy in 44%. On study, 68% also received concomitant ITP therapy. Weekly responses occurred for a median of 11?weeks with romiplostim as compared to 0?weeks with placebo (p?10%) in romiplostim-treated patients included nasopharyngitis, headache, peripheral edema, back pain, and extremity pain. In conclusion, romiplostim significantly increased and maintained platelet counts and was well tolerated in Japanese patients with ITP.     

Remission and platelet responses with romiplostim in primary immune thrombocytopenia: final results from a phase 2 study

In anecdotal reports, some patients with immune thrombocytopenia (ITP) maintained platelet counts after discontinuing romiplostim. Here, we examined rates of platelet response (≥50 × 10⁹/l), remission , splenectomy and adverse events in patients with primary ITP duration ≤6 months who were treated with romiplostim for ≤12 months. The starting dose of romiplostim was 1 μg/kg; concomitant and rescue treatments were permitted to maintain platelet counts. Patients with platelet counts ≥50 × 10⁹/l at the end of 12 months entered a dose taper in which the romiplostim dose was decreased as long as platelet counts were maintained. Remission (platelet count ≥50 × 10⁹/l for 24 consecutive weeks with no ITP treatments) was evaluated in patients once romiplostim was discontinued. Over the 12 months, a high response rate (>90%) was observed. Platelet response occurred quickly (median, ~2 weeks) and was observed for a cumulative median of 11 months. Remission was observed in 24 patients (32%); there were no significantly predictors of remission. Most (20/24) patients had remission start before the forced taper. No new safety signals were identified. Thus, in patients with early‐stage ITP, romiplostim was well tolerated and induced rapid responses, with remission occurring in approximately one‐third of patients (NCT01143038, Amgen 20080435).     

Safety and efficacy of self-administered romiplostim in patients with immune thrombocytopenia: Results of an integrated database of five clinical trials

Romiplostim self-administration by patients or caregivers may offer time/cost savings to healthcare professionals (HCPs) and convenience for patients who avoid weekly clinic visits. We performed an integrated analysis of five clinical trials to evaluate the efficacy and safety of romiplostim self-administration. Data were analyzed from adults with immune thrombocytopenia (ITP) who received weekly romiplostim via self-administration or from an HCP. Patients who achieved a stable romiplostim dose for ≥3 weeks (HCP group ≥5 weeks to provide an appropriate index date to enable comparisons with the self-administration group) with platelet counts ≥50 × 10⁹/L were eligible. In the self-administration (n = 621) vs HCP (n = 133) groups, respectively, median age was 53 vs 58 years, median time since primary ITP diagnosis was 3.7 vs 2.5 years, and median baseline platelet count at ITP diagnosis was 19.0 vs 20.0 × 10⁹/L. In the self-administration and HCP-dosed groups, median romiplostim treatment duration was 89 vs 52 weeks and median total number of doses was 81 vs 50, respectively. In the self-administration and HCP groups, respectively: 95.0% and 100.0% of patients achieved ≥1 platelet response (defined as weekly platelet count ≥50 × 10⁹/L without rescue medication in previous 4 weeks); the median percentage of weeks with a response was 94.5% and 95.9%; and rescue medication was used in 36.7% and 39.8% of patients. Self-administration did not adversely affect safety; duration-adjusted rates for all treatment-emergent adverse events (TEAEs) and bleeding TEAEs were numerically lower with self-administration. Romiplostim self-administration appears effective and well tolerated in eligible patients with ITP.     

Use of eltrombopag after romiplostim in primary immune thrombocytopenia

The thrombopoietin receptor agonists (THPO‐RAs), romiplostim and eltrombopag, are effective and safe in immune thrombocytopenia (ITP). However, the value of their sequential use when no response is achieved or when adverse events occur with one THPO‐RA has not been clearly established. Here we retrospectively evaluated 51 primary ITP adult patients treated with romiplostim followed by eltrombopag. The median age of our cohort was 49 (range, 18–83) years. There were 32 women and 19 men. The median duration of romiplostim use before switching to eltrombopag was 12 (interquartile range 5–21) months. The reasons for switching were: lack of efficacy (n = 25), patient preference (n = 16), platelet‐count fluctuation (n = 6) and side‐effects (n = 4). The response rate to eltrombopag was 80% (41/51), including 67% (n = 35) complete responses. After a median follow‐up of 14 months, 31 patients maintained their response. Efficacy was maintained after switching in all patients in the patient preference, platelet‐count fluctuation and side‐effect groups. 33% of patients experienced one or more adverse events during treatment with eltrombopag. We consider the use of eltrombopag after romiplostim for treating ITP to be effective and safe. Response to eltrombopag was related to the cause of romiplostim discontinuation.     

An open-label extension study evaluating the safety and efficacy of romiplostim for up to 3.5 years in thrombocytopenic Japanese patients with immune thrombocytopenic purpura (ITP)

Long-term use of the thrombopoietin mimetic romiplostim was examined in Japanese patients with chronic immune thrombocytopenic purpura (ITP) in this open-label extension. The starting dose of romiplostim was the previous trial dose or 3 μg/kg/week, which was titrated up to 10 μg/kg/week to maintain platelet counts between 50 and 200 × 10(9)/L. As of April 2010, 44 patients had enrolled; 71 % women, median age 55.5 years, with five patients discontinuing romiplostim due to patient request (2), administrative decision (2), or not achieving study-defined platelet response (1). Median treatment duration was 100 weeks; median average weekly dose was 3.8 μg/kg. Twenty-eight patients (64 %) self-injected romiplostim. The most frequent adverse events were nasopharyngitis and headache. Nine patients (20 %) had a total of 14 serious adverse events (0.31/100 patient-weeks); of these, only oral hemorrhage was considered treatment related. Fifty hemorrhagic adverse events were reported in 20 patients (46 %) (1.12/100 patient-weeks). Ninety-six percent of patients had a platelet response (doubling of baseline platelet count and platelet count ≥ 50 × 10(9)/L). Of the 25 patients receiving concurrent ITP therapy at baseline, all reduced or discontinued the therapy. Eight patients (18 %) received rescue medications. Administration of up to 3.5 years of romiplostim increased platelet counts and was well tolerated in Japanese patients with chronic ITP.     

A phase II, open-label, sequential-cohort, dose-escalation study of romiplostim in Japanese patients with chronic immune thrombocytopenic purpura

This phase II, multicenter, open-label, sequential-cohort, dose-escalation study was designed to evaluate the safety and efficacy of romiplostim, a novel peptibody that increases platelet production, in Japanese patients with chronic immune thrombocytopenic purpura (ITP). Sequential cohorts of four patients each received romiplostim (1, 3, or 6 μg/kg) subcutaneously on days 1 and 8 of the dose-escalation phase. Patients who achieved platelet responses (doubling of baseline platelet counts to ≥50 × 10⁹/L) continued romiplostim weekly during the treatment-continuation phase. Romiplostim produced dose-dependent increases in mean and peak platelet counts. Five patients received romiplostim during the treatment-continuation phase, with platelet counts ≥50 × 10⁹/L maintained in approximately half of the weekly assessments. Romiplostim was well tolerated. No severe, serious, or life-threatening adverse events were reported. No binding antibodies to romiplostim or thrombopoietin were detected. Romiplostim is safe and well tolerated in Japanese patients with chronic ITP and is effective in producing platelet count increases, consistent with the results from studies in non-Japanese patients. On the basis of these findings, a starting dose of 3 μg/kg was recommended for phase III evaluation of romiplostim in Japanese patients with chronic ITP.     

Efficacy and safety of romiplostim in refractory aplastic anaemia: a Phase II/III,multicentre, open‐label study

A previous dose‐finding study has suggested that romiplostim is effective in patients with refractory aplastic anaemia (AA) and 10 µg/kg once weekly was recommended as a starting dose. In this Phase II/III, multicentre, open‐label study, romiplostim was administered subcutaneously at a fixed dose of 10 µg/kg once weekly for 4 weeks (weeks 1–4) followed by weekly doses (5, 10, 15 and 20 µg/kg) titrated by platelet response for up to 52 weeks (weeks 5–52). A total of 31 patients with AA who were refractory to immunosuppressive therapy (IST) and thrombocytopenia (platelet count of ≤30 × 10⁹/l) were enrolled. The primary efficacy endpoint of the proportion of patients achieving any haematological (platelet, neutrophil and erythrocyte) response at week 27 was 84% [95% confidence interval (CI) 66–95%]. Trilineage response was 39% (95% CI 22–58%) at week 53. The most common treatment‐related adverse events (AEs) were headache and muscle spasms (each 13%). All AEs were mild or moderate except for three patients with Grade 3 hepatic AEs; no AEs necessitated romiplostim discontinuation. Two patients developed cytogenetic abnormalities, of whom one returned to normal karyotype at last follow‐up. High‐dose romiplostim is effective and well tolerated in the treatment of patients with AA refractory to IST.     

A randomized, double-blind study of romiplostim to determine its safety and efficacy in children with immune thrombocytopenia

Romiplostim, a thrombopoietin-mimetic peptibody, increases and maintains platelet counts in adults with immune thrombocytopenia (ITP). In this first study of a thrombopoietic agent in children, patients with ITP of ≥ 6 months' duration were stratified by age 1:2:2 (12 months-< 3 years; 3-< 12 years; 12-< 18 years). Children received subcutaneous injections of romiplostim (n = 17) or placebo (n = 5) weekly for 12 weeks, with dose adjustments to maintain platelet counts between 50 × 10(9)/L and 250 × 10(9)/L. A platelet count ≥ 50 × 10(9)/L for 2 consecutive weeks was achieved by 15/17 (88%) patients in the romiplostim group and no patients in the placebo group (P = .0008). Platelet counts ≥ 50 × 10(9)/L were maintained for a median of 7 (range, 0-11) weeks in romiplostim patients and 0 (0-0) weeks in placebo patients (P = .0019). The median weekly dose of romiplostim at 12 weeks was 5 μg/kg. Fourteen responders received romiplostim for 4 additional weeks for assessment of pharmacokinetics. No patients discontinued the study. There were no treatment-related, serious adverse events. The most commonly reported adverse events in children, as in adults, were headache and epistaxis. In this short-term study, romiplostim increased platelet counts in 88% of children with ITP and was well-tolerated and apparently safe. The trial was registered with http://www.clinicaltrials.gov as NCT00515203.     

Romiplostim in children with chronic refractory ITP: randomized placebo controlled study

Romiplostim stimulates thrombopoietin receptor to increase platelet production of megakaryocytes in idiopathic thrombocytopenic purpura (ITP). This study aimed to evaluate the safety and efficacy of romiplostim in children with chronic ITP. Eighteen patients with chronic ITP, either none responsive or failed to maintain response on two or more therapeutic modalities, were enrolled. Patients were randomized (2:1) to receive romiplostim or placebo for 12 weeks, initiated at 1 μg/kg/week, escalated to 5 μg/kg/week, and then tapered. Median patients' age was 8.5 years, and the median baseline platelet count (PC) was 10.5 × 10⁹/L. The median weekly dose of romiplostim was 2 μg/kg. Fifty percent of patients in both romiplostim and placebo arms had at least one adverse event (AE); none was serious. Ten patients on romiplostim (83.3%) maintained the efficacy endpoint (PC > 50,000). Romiplostim was well-tolerated and efficient in treating the children with chronic refractory ITP with no unexpected AEs.     

Thrombopoietin receptor agonists for preparing adult patients with immune thrombocytopenia to splenectomy: results of a retrospective,observational GIMEMA study

In patients with immune thrombocytopenia (ITP) refractory to corticosteroids and intravenous immunoglobulins (IVIG), splenectomy may result at higher risk of peri‐operative complications and, for this reason, potentially contraindicated. The thrombopoietin receptor agonists (TPO‐RAs) romiplostim and eltrombopag have shown high therapeutic activity in primary ITP, but data of efficacy and safety regarding their use in preparation for splenectomy are missing. Thirty‐one adult patients, median age 50 years, with corticosteroids and/or IVIG refractory persistent and chronic ITP who were treated with TPO‐RAs (romiplostim= 24; eltrombopag= 7) with the aim to increase platelet count and allow a safer execution of splenectomy were retrospectively evaluated. Twenty‐four patients (77%) responded to the use of TPO‐RAs with a median platelet count that increased from 11 × 10⁹/L before starting TPO‐RAs to 114 × 10⁹/L pre‐splenectomy, but a concomitant treatment with corticosteroids and/or IVIG was required in 19 patients. Twenty‐nine patients underwent splenectomy while two patients who responded to TPO‐RAs subsequently refused surgery. Post‐splenectomy complications were characterized by two Grade 3 thrombotic events (1 portal vein thrombosis in the patient with previous history of HCV hepatitis and 1 pulmonary embolism), with a platelet count at the time of thrombosis of 260 and 167 × 10⁹/L, respectively and one Grade 3 infectious event. TPO‐RAs may represent a therapeutic option to improve platelet count and reduce the risk of peri‐operative complications in ITP candidates to splenectomy. An increased risk of post‐splenectomy thromboembolic events cannot be ruled out and thromboprophylaxis with low‐molecular weight heparin is generally recommended. Am. J. Hematol. 91:E293–E295, 2016. © 2016 Wiley Periodicals, Inc.     

Romiplostim in adult patients with newly diagnosed or persistent immune thrombocytopenia (ITP) for up to 1 year and in those with chronic ITP for more than 1 year: a subgroup analysis of integrated data from completed romiplostim studies

The thrombopoietin receptor agonist romiplostim is approved for second-line use in chronic immune thrombocytopenia (ITP), but its effects in patients with ITP for ≤1 year are not well characterized. This analysis of pooled data from 9 studies included patients with ITP for ≤1 year (n = 311) or >1 year (n = 726) who failed first-line treatments and received romiplostim, placebo or standard of care. In subgroup analysis by ITP duration, patient incidences for platelet response at ≥75% of measurements were higher for romiplostim [ITP ≤1 year: 74% (204/277); ITP >1 year: 71% (450/634)] than for placebo/standard of care [ITP ≤1 year: 18% (6/34); ITP >1 year: 9% (8/92)]. Of patients with ≥9 months on study, 16% with ITP ≤1 year and 6% with ITP >1 year discontinued romiplostim and maintained platelet counts ≥50 × 10⁹/l for ≥6 months without ITP treatment (treatment-free remission). Independent of ITP duration, rates of serious adverse events and bleeding were lower with romiplostim than placebo/standard of care and thrombotic events occurred at similar rates. In this analysis, romiplostim and placebo/standard of care had similar safety profiles and romiplostim increased platelet counts in patients with either ITP ≤1 year or ITP >1 year, with more treatment-free remission in those with ITP ≤1 year.     

Use of the novel thrombopoietin receptor-agonist romiplostim, in combination with steroids and immunoglobulins for the increase of platelets prior to splenectomy, in refractory immune thrombocytopenia: a case report

This case report describes a patient with relapsed primary immune thrombocytopenic purpura (ITP), in which splenectomy was not possible due to the persistence of a low platelet count despite treatment with corticosteroids, intravenous immunoglobulins (IVIG) and platelet transfusion treatment. As an attempt to increase platelet count prior to performing splenectomy, the thrombopoietin receptor agonist, romiplostim, was administered in combination with steroids and IVIG. A single administration of romiplostim was found to be markedly effective, allowing a rapid and notable platelet increase, required for a well tolerated splenectomy. This case confirms the potent activity of romiplostim in ITP, and indicates that patients with recurrent primary ITP who are unresponsive to conventional immunosuppressive therapy may benefit from the addition of a short course of romiplostim.     

Romiplostim safety and efficacy for immune thrombocytopenia in clinical practice: 2-year results of 72 adults in a romiplostim compassionate-use program

Romiplostim, a thrombopoietic agent with demonstrated efficacy against immune thrombocytopenia (ITP) in prospective controlled studies, was recently licensed for adults with chronic ITP. Only France has allowed romiplostim compassionate use since January 2008. ITP patients could receive romiplostim when they failed to respond to successive corticosteroids, intravenous immunoglobulins, rituximab, and splenectomy, or when splenectomy was not indicated. We included the first 80 patients enrolled in this program with at least 2 years of follow-up. Primary platelet response (platelet count ≥ 50 × 10(9)/L and double baseline) was observed in 74% of all patients. Long-term responses (2 years) were observed in 47 (65%) patients, 37 (79%) had sustained platelet responses with a median platelet count of 106 × 10(9)/L (interquartile range, 75-167 × 10(9)/L), and 10 (21%) were still taking romiplostim, despite a median platelet count of 38 × 10(9)/L (interquartile range, 35-44 × 10(9)/L), but with clinical benefit (lower dose and/or fewer concomitant treatment(s) and/or diminished bleeding signs). A high bleeding score and use of concomitant ITP therapy were baseline factors predicting romiplostim failure. The most frequently reported adverse events were: arthralgias (26%), fatigue (13%), and nausea (7%). Our results confirmed that romiplostim use in clinical practice is effective and safe for severe chronic ITP. This trial was registered at www.clinicaltrials.gov as #NCT01013181.     

Combining thrombopoietin receptor agonists with immunosuppressive drugs in adult patients with multirefractory immune thrombocytopenia,an update on the French experience

Combining drugs could be an effective option for treating multirefractory ITP, that is, patients not responding to rituximab, thrombopoietin receptor agonists (TPO-RA) and splenectomy. We conducted a retrospective, multicenter, observational study including multirefractory ITP patients who received a combination of a TPO-RA and an immunosuppressive drug. We included 39 patients (67% women, median age 59 years [range 21–96]), with a median ITP duration of 57 months [3–393] and a median platelet count at initiation of 10 × 10⁹/L [1–35]. The combination regimen was given for a median duration of 12 months [1–103] and included eltrombopag (51%) or romiplostim (49%), associated with mycophenolate mofetil (54%), azathioprine (36%), cyclophosphamide (5%), cyclosporin (3%) or everolimus (3%). Overall, 30 patients (77%) achieved at least a response (platelet count ≥30 × 10⁹/L and at least doubling baseline during at least 3 months), including 24 complete responses (platelet count >100 × 10⁹/L during at least 3 months) with a median time to response of 30 days [7–270] and a median duration of response of 15 months [4–63]. Severe adverse event related to ITP treatment was observed in 31%. In conclusion, this study confirms that some patients with multirefractory ITP can achieve long lasting response with this combination.     

Romiplostim therapy in children with unresponsive chronic immune thrombocytopenia

Romiplostim, a thrombopoiesis-stimulating peptibody, represents a new therapeutic option in adult refractory chronic immune thrombocytopenia (ITP). This study aimed to assess the short-term efficacy and safety of romiplostim in children with chronic ITP. Eight non-splenectomized patients with chronic ITP refractory to standard lines of medical therapy were recruited from the Pediatric Hematology Unit, Children's Hospital, Ain Shams University, Cairo, Egypt. One patient was initially excluded because of increased bone marrow reticulin (grade 3). Therapy was initiated in seven patients, aged 3.4–15.2 years (median 5.5 years), and the disease duration ranged from 13 months to 7.3 years (median 2.4 years); none were splenectomized. Romiplostim dose was started as 1?µgm/kg/week and the dose escalated by 1?µgm/kg/week according to platelet count. The duration of therapy varied between 1 and 22 weeks (median 12 weeks). Results revealed that four out of the seven patients achieved variable response. Four patients demonstrated rapid increase in platelet count when pulse steroid therapy was added. Most reported adverse events were mild and transient. This case series study reveals variable response rate in children with chronic ITP to romiplostim therapy; addition of steroids especially in emergency bleeding situations could potentiate romiplostim thrombopoietic effect even in patients initially refractory to steroids. Romiplostim safety and efficacy in pediatric ITP needs further long-term studies.     

Romiplostim monotherapy in thrombocytopenic patients with myelodysplastic syndromes: long‐term safety and efficacy

Romiplostim can improve platelet counts in about 50% of patients with low‐ or intermediate 1‐risk (lower risk) myelodysplastic syndromes (MDS) and thrombocytopenia, but its long‐term toxicity and efficacy are not known. This open‐label extension study evaluated the long‐term safety and efficacy of romiplostim in 60 patients with lower risk MDS and platelet counts ≤50 × 10⁹/l. The primary endpoint was adverse event (AE) incidence. Secondary endpoints were efficacy parameters, including bleeding events and platelet response. Median (range) treatment time in the extension study and the median observation times thereafter were 25 (2–181) and 57 (11–209) weeks, respectively. Treatment‐related AEs and serious AEs were reported in 14/60 (23%) and 4/60 (7%) patients, respectively. Progression to acute myeloid leukaemia (AML) occurred in two patients after 44 and 46 weeks. Patients (n = 34, 57%) with a platelet response were further evaluated for length of response. Median (range) response duration was 33 (7–174) weeks; 28/34 (82%) patients had a continuous response. Five of 34 patients (15%) had grade ≥3 bleeding events; three when the platelet count was >50 × 10⁹/l. There were no new safety concerns and the rate of progression to AML was low; response to romiplostim was maintained for most patients.     

Very high frequencies of leukaemia‐initiating cells in precursor T‐acute lymphoblastic leukaemia may be obscured by cryopreservation

Eltrombopag is a thrombopoietin‐receptor agonist that stimulates platelet production and increases platelet counts in patients with chronic immune thrombocytopenia (ITP). This open‐label, single‐arm study evaluated consistency of response and safety following repeated intermittent dosing of eltrombopag 50 mg daily over 3 cycles (1 cycle = up to 6 weeks on therapy followed by up to 4 weeks off therapy). The primary endpoint was proportion of patients with a response (platelet count ≥50 × 10⁹/l and ≥2× baseline) in Cycle 1 who subsequently responded in Cycle 2 or 3. Fifty‐two of 65 evaluable patients (80%) responded in Cycle 1; these responding patients comprised the primary analysis population. Of these, 45/52 (87%) responded in Cycle 2 or 3 [95% confidence interval (CI), 74–94%] and 34/48 (71%; 95% CI, 56–83%) responded in both Cycles 2 and 3. Time to response was consistent, with >50% of responders responding by Day 8 in each cycle. Bleeding rates relative to baseline decreased by approximately 50% during each treatment cycle. The frequency or severity of adverse events, most commonly headache, did not increase over successive cycles. If a chronic ITP patient not requiring consistent therapy responds to short‐term eltrombopag, then subsequent courses of eltrombopag, as needed, are likely to be safe and effective.     

Safety and efficacy of long-term treatment with romiplostim in thrombocytopenic patients with chronic ITP

Chronic immune thrombocytopenic purpura (ITP) is characterized by low platelet counts and mucocutaneous bleeding. In previous studies romiplostim (AMG531), a thrombopoiesis-stimulating protein, increased platelet counts in most patients with chronic ITP. This ongoing, long-term open-label, single-arm study investigated safety and efficacy in patients who completed a previous romiplostim study and had platelet counts less than or equal to 50 [corrected] x 10(9)/L. One hundred forty-two patients were treated for up to 156 weeks (mean, 69 weeks). Platelet responses (platelet count > or = 50 x 10(9)/L and double baseline) were observed in 87% of all patients and occurred on average 67% of the time in responding patients. In 77% of patients, the romiplostim dose remained within 2 microg/kg of their most frequent dose at least 90% of the time. Ninety patients (63%) received treatment by self-administration. Treatment-related serious adverse events were reported in 13 patients (9%). Bone marrow reticulin was observed in 8 patients; marrows were not routinely performed in this study, so the true incidence of this event cannot be determined. Severe bleeding events were reported in 12 patients (9%). Thrombotic events occurred in 7 patients (5%). In conclusion, romiplostim increased platelet counts in most patients for up to 156 weeks without tachyphylaxis and had an acceptable safety profile. (ClinicalTrials.gov Identifier NCT00116688).     

Romiplostim therapy in children with unresponsive chronic immune thrombocytopenia

Romiplostim, a thrombopoiesis-stimulating peptibody, represents a new therapeutic option in adult refractory chronic immune thrombocytopenia (ITP). This study aimed to assess the short-term efficacy and safety of romiplostim in children with chronic ITP. Eight non-splenectomized patients with chronic ITP refractory to standard lines of medical therapy were recruited from the Pediatric Hematology Unit, Children's Hospital, Ain Shams University, Cairo, Egypt. One patient was initially excluded because of increased bone marrow reticulin (grade 3). Therapy was initiated in seven patients, aged 3.4-15.2 years (median 5.5 years), and the disease duration ranged from 13 months to 7.3 years (median 2.4 years); none were splenectomized. Romiplostim dose was started as 1 μgm/kg/week and the dose escalated by 1 μgm/kg/week according to platelet count. The duration of therapy varied between 1 and 22 weeks (median 12 weeks). Results revealed that four out of the seven patients achieved variable response. Four patients demonstrated rapid increase in platelet count when pulse steroid therapy was added. Most reported adverse events were mild and transient. This case series study reveals variable response rate in children with chronic ITP to romiplostim therapy; addition of steroids especially in emergency bleeding situations could potentiate romiplostim thrombopoietic effect even in patients initially refractory to steroids. Romiplostim safety and efficacy in pediatric ITP needs further long-term studies.     

Romiplostim in children with chronic immune thrombocytopenia (ITP): the French Experience

A minority of children with chronic immune thrombocytopenia (ITP) require therapeutic intervention to prevent haemorrhagic risk. This retrospective national study evaluated romiplostim in childhood non‐responsive or refractory chronic ITP. Between 2009 and 2012, 10 patients whose Buchanan score was 3–4 were treated with romiplostim. The median duration of thrombocytopenia was 1·9 years (0·8–15). The median duration of romiplostim treatment was 9 months (3–36). A response was observed in 5/10 patients (one complete, four partial). No serious adverse effect was noticed. The long‐term benefit/risk balance of this innovative treatment is currently recorded by Centre de Référence National des Cytopénies Auto‐immunes de l'Enfant.