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.     

Development and validation of a model to predict platelet response to romiplostim in patients with lower‐risk myelodysplastic syndromes

Low endogenous erythropoietin levels and limited red blood cell transfusion history can predict response to erythropoiesis‐stimulating agents in anaemic patients with myelodysplastic syndromes (MDS). The relationship between endogenous thrombopoietin (THPO) levels and platelet response to romiplostim is unknown. Variables including baseline endogenous THPO levels, transfusion needs, and platelet response were analysed in a randomized trial of 250 thrombocytopenic, lower‐risk MDS patients (International Prognostic Scoring System low/intermediate‐1). A predictive scoring system was developed based on log–likelihood ratios and logistic coefficients. Patients with HI–P (haematological improvement – platelets) responses had lower mean baseline THPO levels (P = 0·0497) and were more likely to have <6 platelet units transfused in the past year (P = 0·0027), as did patients with platelet responses ≥50% of weeks on romiplostim (P = 0·001 and P = 0·0037, respectively). A model for predicting response to romiplostim was developed and validated in a separate MDS cohort (N = 72). Patients in low‐, intermediate‐, and high‐response groups had response rates of 17·4%, 29·6%, and 50·7%, respectively, for HI‐P, and 17·4%, 33·8%, and 65·2%, respectively, for ≥50% response. For thrombocytopenic patients with lower‐risk MDS, lower baseline THPO levels (<500 pg/ml) and limited platelet transfusion history predicted a greater likelihood of a subsequent platelet response to romiplostim.     

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.     

Safety and efficacy of thrombopoietin‐receptor agonists in myelodysplastic syndromes: a systematic review and meta‐analysis of randomized controlled trials

Thrombocytopenia is common (40–65%) and potentially serious in myelodysplastic syndromes (MDS). A systematic review was conducted to determine the safety and efficacy of adding a thrombopoietin‐receptor (THPO‐R) agonist to standard MDS treatment. MEDLINE, EMBASE and CENTRAL databases were searched. We included randomized controlled trials comparing a THPO‐R agonist to placebo. A meta‐analysis of the effects was performed. Endpoints included bleeding and platelet transfusion rates, risk of progression to acute myeloid leukaemia (AML) and mortality. Three hundred and eighty four patients from five trials were included, four using romiplostim and one using eltrombopag. Overall, the relative risk (RR) of bleeding with romiplostim versus placebo was 0·84 [95% confidence interval (CI): 0·57–1·24]. However, compared to placebo, romiplostim significantly decreased the exposure‐adjusted bleeding rate (RR 0·92; 95% CI: 0·86–0·99), as well as the exposure‐adjusted platelet transfusion rate (RR 0·69; 95% CI: 0·53–0·88). The RR of AML progression with romiplostim was 1·36 (95% CI: 0·54–3·40), however the outcome data were judged as higher risk of bias. Romiplostim is promising in its ability to decrease patient‐important outcomes: bleeding and platelet transfusion need. Although the risk of AML progression was not increased, due to unclear risk of bias in the data, this safety concern is difficult to assess. Therefore, romiplostim cannot yet be routinely recommended. Early eltrombopag data is promising.     

Phase II study of tosedostat with cytarabine or decitabine in newly diagnosed older patients with acute myeloid leukaemia or high‐risk MDS

Tosedostat, an oral aminopeptidase inhibitor, has synergy with cytarabine and hypomethylating agents. We performed a Phase II trial to determine rates of complete remission (CR) and survival using tosedostat with cytarabine or decitabine in older patients with untreated acute myeloid leukaemia (AML) or high‐risk myelodysplastic syndrome (MDS). Thirty‐four patients ≥60 years old (median age 70 years; range, 60–83) were randomized to receive tosedostat (120 mg on days 1–21 or 180 mg continuously) with 5 d of either cytarabine (1 g/m²/d) or decitabine (20 mg/m²/d) every 35 d. Twenty‐nine patients (85%) had AML, including 15 (44%) with secondary AML/MDS, and 5 (15%) had MDS‐refractory anaemia with excess blasts type 2. The CR/CR with incomplete count recovery (CRi) rate was 53% [9 in each arm; 14 CR (41%) and 4 CRi (12%)], attained in 6 of 14 patients with adverse cytogenetics and 4 of 7 with FLT3‐internal tandem duplication mutations. Median follow‐up was 11·2 months (range, 0·5–22·3), and median survival was 11·5 months (95% confidence interval, 5·2–16·7). Twenty‐three patients (67·6%) were treated as outpatients and 10 of these patients required hospitalization for febrile neutropenia. No Grade 3–4 non‐haematological toxicities required withdrawal from study. Tosedostat with cytarabine or decitabine is tolerated in older patients with untreated AML/MDS, results in a CR/CRi rate of >50%, and warrants further study in larger trials.     

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).     

Romiplostim for the management of perioperative thrombocytopenia

Thrombocytopenic patients requiring invasive surgery have few options to improve their platelet count preoperatively. This is a single‐centre, retrospective review of thrombocytopenic patients receiving the thrombopoietin receptor agonist romiplostim perioperatively to allow for surgical interventions. Patient characteristics, romiplostim use, and surgical and safety outcomes (bleeding, thrombosis, transfusions) were collected and analysed. Forty‐seven patients underwent 51 surgical procedures (ranging from total hip arthroplasty to open cardiac surgery) with romiplostim support. Thrombocytopenia aetiologies included immune thrombocytopenia, chronic liver disease, haematological malignancy, drug‐related thrombocytopenia, and hereditary thrombocytopenia. Median (range) platelet counts improved, from 47 × 10⁹/l (9–120 × 10⁹/l) at romiplostim initiation to 164 × 10⁹/l (28–603 × 10⁹/l) at the time of surgery (P < 0·0001). A dose of 3 μg/kg per week for 2 doses increased the platelet count to >100 × 10⁹/l in 79% of patients within 14 days. In 96% of cases, surgery proceeded on schedule without delay or cancellation. Four patients had bleeding events unrelated to thrombocytopenia and 1 patient developed deep venous thrombosis. Six patients required red cell transfusion and 3 patients required platelet transfusion perioperatively. In conclusion, romiplostim was effective in increasing platelet counts to allow surgery to proceed safely and on schedule. Bleeding and thromboembolic events were within acceptable limits for this surgical population.     

A phase 2 trial of high dose lenalidomide in patients with relapsed/refractory higher‐risk myelodysplastic syndromes and acute myeloid leukaemia with trilineage dysplasia

Limited therapies exist for patients with refractory and relapsed (RR ) higher‐risk myelodysplastic syndromes (HR ‐MDS ) and acute myeloid leukaemia with trilineage dysplasia (AML ‐TD ). High dose (HD ) lenalidomide (50 mg) has activity as frontline therapy in elderly AML but there is limited data in the RR setting. This phase II trial included patients with RR HR ‐MDS or AML ‐TD at 2 doses of lenalidomide (15 or 50 mg) on days 1–28 of 42‐day cycles. The primary endpoint was response rate using the 2006 International Working Group criteria. Overall survival (OS ) was estimated by Kaplan–Meier methods. Of 27 patients enrolled, 59% had HR ‐MDS and 31% AML ‐TD . No patient had isolated del5q; 41% had poor‐risk karyotype. Of 9 patients treated at 15 mg, 56% completed ≥2 cycles with no responses. Of 18 patients treated at 50 mg, 39% completed ≥2 cycles and 11% responded but all experienced grade 3/4 neutropenic fever/infection. The 60‐day mortality rate was 30%. Median OS was 114 days with 19% surviving ≥1 year. The study was terminated due to lack of robust clinical activity. In conclusion, lenalidomide at 15 mg is ineffective in RR myeloid malignancies. Continous high dosing schedules are poorly tolerated and minimally active. Further evaluation should be considered in upfront intensive chemotherapy‐ineligible patients.     

Association between Chiari malformation and bone marrow failure/myelodysplastic syndrome

Romiplostim was effective, safe, and well‐tolerated over 6–12 months of continuous treatment in Phase 3 trials in patients with immune thrombocytopenia (ITP). This report describes up to 5 years of weekly treatment with romiplostim in 292 adult ITP patients in a long‐term, single‐arm, open‐label study. Outcome measures included adverse events (including bleeding, thrombosis, malignancy, and reticulin/fibrosis), platelet response (platelet count >50 × 10⁹ per litre), and the proportion of patients requiring rescue treatments. Treatment–related serious adverse events were infrequent and did not increase with longer treatment. No new classes of adverse events emerged. Thrombotic events occurred in 6·5% of patients and were not associated with platelet count. Median platelet counts of 50–200 × 10⁹ per litre were maintained with stable doses of romiplostim (mean 5–8 μg/kg; generally self‐administered at home) throughout the study. A platelet response was achieved at least once by 95% of patients, with a platelet response maintained by all patients on a median 92% of study visits. There was a low rate of bleeding and infrequent need for rescue treatments. In conclusion, this study demonstrated that romiplostim was safe and well‐tolerated over 614 patient‐years of exposure in ITP patients, and that efficacy was maintained with stable dosing for up to 5 years of continuous treatment.     

Assessment of romiplostim immunogenicity in adult patients in clinical trials and in a global postmarketing registry

Antibodies to first-generation recombinant thrombopoietin (TPO) neutralized endogenous TPO and caused thrombocytopenia in some healthy subjects and chemotherapy patients. The second-generation TPO receptor agonist romiplostim, having no sequence homology to TPO, was developed to avoid immunogenicity. This analysis examined development of binding and neutralising antibodies to romiplostim or TPO among adults with immune thrombocytopenia (ITP) in 13 clinical trials and a global postmarketing registry. 60/961 (6·2%) patients from clinical trials developed anti-romiplostim-binding antibodies post-baseline. The first positive binding antibody was detected 14 weeks (median) after starting romiplostim, at median romiplostim dose of 2 µg/kg and median platelet count of 29.5 × 10⁹/l; most subjects had ≥98·5% of platelet assessments showing response. Neutralising antibodies to romiplostim developed in 0·4% of patients, but were unrelated to romiplostim dose and did not affect platelet count. Thirty-three patients (3·4%) developed anti-TPO-binding antibodies; none developed anti-TPO-neutralising antibodies. In the global postmarketing registry, 9/184 (4·9%) patients with spontaneously submitted samples had binding antibodies. One patient with loss of response had anti-romiplostim-neutralising antibodies (negative at follow-up). Collectively, anti-romiplostim-binding antibodies developed infrequently. In the few patients who developed neutralising antibodies to romiplostim, there was no cross-reactivity with TPO and no associated loss of platelet response.     

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.     

Azacitidine in untreated acute myeloid leukemia: A report on 149 patients

Limited data are available on azacitidine (AZA) treatment and its prognostic factors in acute myeloid leukemia (AML). One hundred and forty‐nine previously untreated AML patients considered ineligible for intensive chemotherapy received AZA in a compassionate patient‐named program. AML diagnosis was de novo, post‐myelodysplastic syndromes (MDS), post‐MPN, and therapy‐related AML in 51, 55, 13, and 30 patients, respectively. Median age was 74 years, median white blood cell count (WBC) was 3.2 × 10⁹/L and 58% of the patients had ≥30% marrow blasts. Cytogenetics was adverse in 60 patients. Patients received AZA for a median of five cycles (range 1–31). Response rate (including complete remission/CR with incomplete recovery/partial remission) was 27.5% after a median of three cycles (initial response), and 33% at any time (best response). Only adverse cytogenetics predicted poorer response. Median overall survival (OS) was 9.4 months. Two‐year OS was 51% in responders and 10% in non‐responders (P<0.0001). Adverse cytogenetics, WBC >15 × 10⁹/L and ECOG‐PS ≥2 predicted poorer OS, while age and marrow blast percentage had no impact. Using MDS IWG 2006 response criteria, among patients with stable disease, those with hematological improvement had no significant survival benefit in a 7 months landmark analysis. Outcomes observed in this high‐risk AML population treated with AZA deserve comparison with those of patients treated intensively in prospective studies. Am. J. Hematol. 89:410–416, 2014. © 2013 Wiley Periodicals, Inc.     

Clinical outcome after failure of hypomethylating therapy for myelodysplastic syndrome

Around half of patients with myelodysplastic syndrome (MDS) fail to respond to hypomethylating therapy (HMT) and most responders progress within 2 yr. Retrospective studies report poor outcomes after HMT failure. Here, we analyzed the outcomes of patients suffering HMT failure. Of 149 patients with MDS treated with either azacitidine or decitabine, 91 who experienced HMT failure were included in the study. Median overall survival (OS) was 12.1 months: 16.2 months for lower‐risk MDS and 9.3 months for higher‐risk MDS. Disease status and progression to acute myeloid leukemia (AML) at the time of HMT failure were independent prognostic factors for OS. Fifty‐four patients received one or more treatment modalities, and 23 received allogeneic hematopoietic cell transplantation (HCT). The objective response to non‐transplant treatments was poor (11–17%), whereas 17 transplanted patients showed a complete response. OS probability at 2 yr post‐HCT was 60.9%: 78.6% for patients receiving HCT during MDS and 33.3% for those receiving HCT after developing AML. In conclusion, the clinical outcome of patients after HMT failure was poor. Long‐term disease‐free survival was observed in approximately 50% of patients who received allogeneic HCT. Therefore, allogeneic HCT should be performed early in appropriate patients, and particularly before progression to AML.     

Platelet doubling after the first azacitidine cycle is a promising predictor for response in myelodysplastic syndromes (MDS), chronic myelomonocytic leukaemia (CMML) and acute myeloid leukaemia (AML) patients in the Dutch azacitidine compassionate named patient programme

The efficacy of azacitidine in the treatment of high‐risk myelodysplastic syndromes (MDS), chronic myelomonocytic leukaemia (CMML) and acute myeloid leukaemia (AML) (20–30% blasts) has been demonstrated. To investigate the efficacy of azacitidine in daily clinical practice and to identify predictors for response, we analysed a cohort of 90 MDS, CMML and AML patients who have been treated in a Dutch compassionate named patient programme. Patients received azacitidine for a median of five cycles (range 1–19). The overall response rate (complete/partial/haematological improvement) was 57% in low risk MDS, 53% in high risk MDS, 50% in CMML, and 39% in AML patients. Median overall survival (OS) was 13·0 (9·8–16·2) months. Multivariate analysis confirmed circulating blasts [Hazard Ratio (HR) 0·48, 95% confidence interval (CI) 0·24–0·99; P = 0·05] and poor risk cytogenetics (HR 0·45, 95% CI 0·22–0·91; P = 0·03) as independent predictors for OS. Interestingly, this analysis also identified platelet doubling after the first cycle of azacitidine as a simple and independent positive predictor for OS (HR 5·4, 95% CI 0·73–39·9; P = 0·10). In conclusion, routine administration of azacitidine to patients with variable risk groups of MDS, CMML and AML is feasible, and subgroups with distinct efficacy of azacitidine treatment can be identified.     

A phase I/II study of oral clofarabine plus low‐dose cytarabine in previously treated acute myeloid leukaemia and high‐risk myelodysplastic syndrome patients at least 60 years of age

Outcomes for older adults with acute myeloid leukaemia (AML) and myelodysplastic syndrome (MDS) are generally poor, and new effective therapies are needed. We investigated oral clofarabine combined with low‐dose cytarabine (LDAC) in patients aged 60 years and above with relapsed or refractory AML or high‐risk MDS in a phase I/II trial. A 3 + 3 dose escalation of oral clofarabine was followed by a phase II expansion with the aim of obtaining a complete response (CR) rate ≥30%. We identified 20 mg/d for 5 d as the maximum tolerated dose (MTD) of oral clofarabine. A total of 35 patients, with a median age of 72 years, were treated. Of 26 patients enrolled at the MTD, 4 had treatment‐related grade 3–4 non‐haematological toxicities, but none died within 28 d. The observed CR rate and median survival were 34% [95% confidence interval (CI), 18–50%] and 6·8 months overall and 38% [95% CI, 19–57%] and 7·2 months at the MTD. The median disease‐free survival was 7·4 months. Fifty‐two percent (23/44) of cycles administered at the MTD were done without hospital admission. This combination of oral clofarabine and LDAC demonstrated efficacy with a CR rate of >30% and acceptable toxicity in older patients.     

Phase II clinical study of erlotinib for treatment of myelodysplastic syndromes

Outcome in patients with myelodysplastic syndrome (MDS) after azanucleoside failure is poor with unmet need for active novel agents. Preclinical data have suggested that erlotinib has in vivo and in vitro off epidermal growth factor receptor (EGFR)‐target activity in MDS. We conducted a phase II study with single‐agent erlotinib 150 mg/day orally in MDS patients following azanucleoside failure. All intermediate‐2 or high‐risk MDS patients by International Prognostic Scoring System and only those low/intermediate‐1 patients with transfusion‐dependent anemia or platelet counts <50 × 10⁹/L or a significant clinical hemorrhage requiring platelet transfusion or ANC <1 × 10⁹/L were eligible, with most of our patients being at high risk. In 35 eligible patients, overall best response was 14% (3 patients having marrow complete response and 2 hematological improvement). Four deaths occurred on study (sepsis, intracranial hemorrhage, sudden death, and acute myeloid leukemia (AML)). The most common observed grade 3/4 toxicities according to CTCAE v3 were diarrhea (17.1%), rash (17.1%), and infection (11.6%), accompanied by fatigue, thrombocytopenia, and anorexia at 5.7% each. Median overall survival was 6.8 months (95% CI 4.9–13.2), and leukemia‐free survival was 5 months (95% CI 3.4–7.3). Erlotinib was generally well tolerated, with modest single‐agent activity. Given these results and preclinical data suggesting synergistic effect with azanucleosides, the combination should be further explored. Am. J. Hematol. 89:809–812, 2014. © 2014 Wiley Periodicals, Inc.     

Interactions and relevance of blast percentage and treatment strategy among younger and older patients with acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS)

Acute myeloid leukemia (AML) is defined as ≥20% myeloblasts, representing a change from original guidelines where ≤30% blasts were considered as myelodysplastic syndromes (MDS), and 20–29% blasts classified as refractory anemia with excess blasts in transformation (RAEB‐T). Whether the diagnostic bone marrow blast percentage has current value with regards to patient prognostication or identification of optimal treatment strategies is unclear. We retrospectively studied 1652 treatment‐naïve adults with MDS or AML and ≥10% blasts from January 2000 to April 2014. Patients with 20–29% blasts were more similar to MDS patients in terms of advanced age, increased frequency of poor‐risk cytogenetics, lower WBC count, and less frequent NPM1 and FLT3‐ITD mutations. Median overall survival of MDS and RAEB‐T were similar, 16.0 and 16.0 months, compared to 13.5 months for AML with ≥30% blasts (P = 0.045). Multivariate analysis showed inferior survival with increased age (HR 1.81 age 60–69, HR 2.68 age ≥70, P < 0.0005); poor‐risk cytogenetics (HR 2.25, P < 0.0005); therapy‐related disease (HR 1.44, P < 0.0005); and markers of proliferative disease including WBC ≥25 × 10⁹/L (HR 1.35, P = 0.0003), elevated LDH count (HR 1.24, P = 0.0015), and peripheral blasts (HR 1.25, P = 0.004). Among younger patients (≤60 years), intensive AML‐type therapy resulted in similar outcomes regardless of blast percentage, suggesting this to be optimal therapy in this context. Among older patients (≥70 years), patients with 20–29% blasts had similar outcomes to patients with <20% blasts, and better than those with ≥30% blasts. In addition, among older patients, epigenetic therapy provided at least equivalent outcome to intensive chemotherapy. Am. J. Hematol. 91:227–232, 2016. © 2015 Wiley Periodicals, Inc.     

A multicenter study of romiplostim for chemotherapy-induced thrombocytopenia in solid tumor s and hematologic malignancies

Chemotherapy-induced thrombocytopenia (CIT) frequently complicates cancer treatment causing chemotherapy treatment delays, dose reductions, and discontinuation. There is no US Food and Drug Administration (FDA)-approved agent available to manage CIT. This study retrospectively evaluated patients with CIT treated on institutional romiplostim treatment pathways at four US centers. The primary outcome was achievement of a romiplostim response (median on-romiplostim platelet count ≥75x10⁹/L and ≥30x10⁹/L above baseline). Secondary outcomes included time to platelet count ≥100x10⁹/L and rates of the following: platelet count <100×10⁹/L, platelet count <75x10⁹/L, platelet count <50x10⁹/L, thrombocytosis, chemotherapy dose reduction/treatment delay, platelet transfusion, bleeding, and thromboembolism. Multivariable regression was used to identify predictors of romiplostim non-response and compare weekly dosing with intracycle/intermittent dosing. A total of 173 patients (153 solid tumor, 20 lymphoma or myeloma) were treated, with 170 (98%) receiving a median of four (range: 1-36) additional chemotherapy cycles on romiplostim. Romiplostim was effective in solid tumor patients: 71% of patients achieved a romiplostim response, 79% avoided chemotherapy dose reductions/treatment delays, and 89% avoided platelet transfusions. Median per-patient platelet count on romiplostim was significantly higher than baseline (116x10⁹/L vs. 60x10⁹/L; P<0.001). Bone marrow (BM) tumor invasion, prior pelvic irradiation, and prior temozolomide exposure predicted romiplostim non-response. Bleeding rates were lower than historical CIT cohorts and thrombosis rates were not elevated. Weekly dosing was superior to intracycle dosing with higher response rates and less chemotherapy dose reductions/treatment delays/bleeding; intracycle dosing had an incidence rate ratio (IRR) for dose reduction/treatment delay of 3.00 (95%CI: 1.30-6.91; P=0.010) and an IRR for bleeding of 4.84 (95%CI: 1.18-19.89, P=0.029) compared with weekly dosing. Blunted response (10% response rate) was seen in non-myeloid hematologic malignancy patients with BM involvement. In conclusion, romiplostim was safe and effective for CIT in most solid tumor patients.     

Phase II study of targeted therapy with temozolomide in acute myeloid leukaemia and high‐risk myelodysplastic syndrome patients pre‐screened for low O6‐methylguanine DNA methyltransferase expression

Resistance to temozolomide is largely mediated by the DNA repair enzyme O⁶‐methylguanine DNA methyltransferase (MGMT). We conducted a prospective multicentre study of patients with previously untreated acute myeloid leukaemia (AML) or high‐risk myelodysplastic syndrome (MDS) who were not candidates for intensive therapy. Patient selection was based on MGMT expression by Western blot. Patients with MGMT:ACTB (β‐actin) ratio <0·2 were eligible to receive temozolomide 200 mg/m²/d ×7 d. Patients achieving a complete response (CR) could receive up to 12 monthly cycles of temozolomide ×5/28 d. Of 166 patients screened, 81 (49%) demonstrated low MGMT expression; 45 of these were treated with temozolomide. The overall response rate was 53%; 36% achieved complete clearance of blasts, with 27% achieving a CR/CR with incomplete platelet recovery (CRp). Factors associated with a trend toward a higher response rate included MDS, methylated MGMT promoter and standard cytogenetic risk group. Induction and post‐remission cycles were well‐tolerated and most patients were treated on an outpatient basis. Patient who achieved CR/CRp had a superior overall survival compared to partial or non‐responders. In conclusion, targeted therapy based on pre‐selection for low MGMT expression was associated with a higher response rate to temozolomide compared to previous reports of unselected patients.     

Combined bezafibrate and medroxyprogesterone acetate have efficacy without haematological toxicity in elderly and relapsed acute myeloid leukaemia (AML)

Acute myeloid leukaemia (AML) causes life‐threatening deficits of functional blood cells that require management using red cell and platelet transfusion and aggressive treatment of neutropenic infections. Current cytotoxic chemotherapy further worsens the problem of reduced haemopoiesis and two‐thirds of patients are too frail to tolerate intensive chemotherapy at all. Median survival amongst these patients remains at <3 months emphasizing the urgent need for anti‐AML therapies that do not suppress haemopoiesis. Our laboratory studies showed combined Bezafibrate and Medroxyprogesterone acetate (BaP) had activity against AML without toxicity to normal stem cells. Here we report the safety and efficacy of BaP in 20 patients (19 AML, 1 high‐risk myelodysplasia) for whom intensive chemotherapy was not an option. No patient exhibited haematological toxicity from BaP. Eleven patients took BaP alone for >4 weeks. One reverted from high risk myelodysplasia and remains transfusion independent after 201 weeks of therapy. Three AML patients gained major haematological improvements for 22–30 weeks; in one, marrow was available to document a partial AML response. Thus, this trial indicates that BaP therapy has potential for treatment of elderly and relapsed AML.