Optimizing management of ruxolitinib in patients with myelofibrosis: the need for individualized dosing

Ruxolitinib, an oral JAK1 and JAK2 inhibitor, is approved in the US for patients with intermediate or high-risk myelofibrosis (MF), a chronic neoplasm associated with aberrant myeloproliferation, progressive bone marrow fibrosis, splenomegaly, and burdensome symptoms. Phase III clinical studies have shown that ruxolitinib reduces splenomegaly and alleviates MF-related symptoms, with concomitant improvements in quality of life measures, for the overwhelming majority of treated patients. In addition, ruxolitinib provided an overall survival advantage as compared with either placebo or what was previously considered best available therapy in the two phase III studies. The most common adverse events with ruxolitinib treatment include dose-dependent anemia and thrombocytopenia, which are expected based on its mechanism of action. Experience from the phase III studies shows that these hematologic events can be managed effectively with dose modifications, temporary treatment interruptions, as well as red blood cell transfusions in the case of anemia and, importantly, are rarely cause for permanent treatment discontinuation. This review summarizes data supporting appropriate individualized patient management through careful monitoring of blood counts and dose titration as needed in order to maximize treatment benefit.     

Myeloid metaplasia in aspirates from enlarged spleens: a clue in the absence of peripheral blood findings characteristic of myelofibrosis

OBJECTIVE: To assess the significance of finding myeloid metaplasia in splenic aspirates from patients presenting with mild to moderate firm splenomegaly, in the absence of characteristic peripheral blood findings, in diagnosing idiopathic myelofibrosis. STUDY DESIGN: Archival records pertaining to 14 patients diagnosed as having myeloid metaplasia on splenic aspirates performed between September 2000 and April 2004 were analyzed. RESULTS: The relevant findings in these 9 women and 5 men were: splenic enlargement 17-21 cm with homogeneous echotexture on ultrasonography, hemoglobin 4-10 g/dL, variable pattern of anemia, total leukocyte count 6,300-28,800/ mm3 with neutrophilia and a few late myeloid precursors on the differential count, normal platelet counts, dry bone marrow tap in 10 patients and cellular marrow aspirate with prominence of megakaryocytes dispersed in a maturing cell population of myeloid and erythroid series in 4 patients. Splenic aspirates yielded foci of trilineage hematopoiesis suggestive of myeloid metaplasia, possibly due to myelofibrosis of idiopathic type, as confirmed on trephine biopsy in all cases. CONCLUSION: Splenic aspirates may be a useful tool for detecting myeloid metaplasia suggesting myelofibrosis when peripheral blood findings are not yet characteristic of the same. The procedure was not associated with any complications.     

Oral oxymetholone reduces mortality induced by gamma irradiation in mice through stimulation of hematopoietic cells

Oxymetholone is a 17α -alkylated anabolic-androgenic steroid. This drug can stimulate bone marrow cells and increase the blood cells in the peripheral blood vessels. It has been used for the treatment of anemia caused by low red cell production. Since oxymetholone has hematopoietic effect, we studied radioprotective effects of this drug in mice. In this study, we determined percentage of survival, dose-reduction factor (DRF) and hematological parameters in irradiated mice which treated with or without oxymetholone. Oxymetholone administrated at different doses 80, 160, 320, 640 mg/kg by gavages at 24 h before 8 Gy gamma irradiation. At 30 days after treatment, the following percentage of animals survival in each group was as: 80 mg/kg, 50%; 160 mg/kg, 50%; 320 mg/kg, 55%; 640 mg/kg, 75% and vehicle, 15%. Percentage of survival increased in all of treated groups statistically compared with irradiated-vehicle group. In the groups treated by oxymetholone, maximum protection was realized at 640 mg/kg. In order to calculate the DRF for oxymetholone, mice were exposed to whole-body gamma irradiation with dose ranges between 5.83 and 11.23 Gy. The probit line for oxymetholone-treated mice was shifted to the right with a DRF of 1.14. In mice exposed to whole-body gamma-irradiation (4 Gy), an oral administration of 640 mg/kg oxymetholone ameliorated radiation-induced decreases in circulating platelets and erythrocytes, but had a less effect on total number of WBC. These results demonstrate that oxymetholone stimulates myelopoiesis and thrombocytopenia and enhances survival in mice after ionizing radiation.     

Severe thrombocytopenia in Epstein-Barr virus-induced mononucleosis.

Severe thrombocytopenia is a rare complication of Epstein-Barr virus-induced infectious mononucleosis. We evaluated the clinical and laboratory data from seven patients seen between 1976 and 1985 whose lowest platelet counts varied from 3 to 25 x 10(9) per liter. Five of the seven patients were initially thought to have either acute leukemia or idiopathic thrombocytopenic purpura; eventually, however, primary Epstein-Barr virus infections were confirmed in all patients. Two of six patients tested had antiplatelet antibodies during the acute phase of their illnesses. Eight additional patients with acute disease who had only mild thrombocytopenia (94 to 144 x 10(9) per liter) were also tested for platelet antibodies with negative results. Steroid therapy was administered to three patients and platelet transfusions to one. All seven patients recovered with no serious hemorrhagic sequelae.     

T-lymphocyte subpopulations in the peripheral blood and bone marrow of patients with aplastic anemia

A decrease in the absolute number of total lymphocytes, OKT3+ and OKT4+ lymphocytes, and a normal number of OKT8+ lymphocytes were found in the peripheral blood of patients with aplastic anemia. The OKT4:OKT8 ratio was decreased in patients due to a reduction in the percentage of OKT4+ cells and 3 out of 18 patients had a ratio less than 1. The values of the OKT4:OKT8 ratio were not associated either with the severity of the disease or with treatment with androgens. There was no correlation between the OKT4:OKT8 ratio and the number of transfusions received by patients. On the other hand, studies performed with bone marrow lymphocytes showed that the OKT4:OKT8 ratio for both patients and controls was lower than that of the peripheral blood. Since the ratio of OKT4:OKT8 cells in aplastic and control bone marrow was similar no direct pathogenic role can be assigned to the marrow for the imbalance detected in the peripheral blood.     

Interim analysis of safety and efficacy of ruxolitinib in patients with myelofibrosis and low platelet counts

Background

Ruxolitinib, a Janus kinase 1 and 2 inhibitor, demonstrated improvements in spleen volume, symptoms, and survival over placebo and best available therapy in intermediate-2 or high-risk myelofibrosis patients with baseline platelet counts ≥100?×?10⁹/L in phase III studies. The most common adverse events were dose-dependent anemia and thrombocytopenia, which were anticipated because thrombopoietin and erythropoietin signal through JAK2. These events were manageable, rarely leading to treatment discontinuation. Because approximately one-quarter of MF patients have platelet counts <100?×?10⁹/L consequent to their disease, ruxolitinib was evaluated in this subset of patients using lower initial doses. Interim results of a phase II study of ruxolitinib in myelofibrosis patients with baseline platelet counts of 50-100?×?10⁹/L are reported.

Methods

Ruxolitinib was initiated at a dose of 5 mg twice daily (BID), and doses could be increased by 5 mg once daily every 4 weeks to 10 mg BID if platelet counts remained adequate. Additional dosage increases required evidence of suboptimal efficacy. Assessments included measurement of spleen volume by MRI, MF symptoms by MF Symptom Assessment Form v2.0 Total Symptom Score [TSS]), Patient Global Impression of Change (PGIC); EORTC QLQ-C30, and safety/tolerability.

Results

By week 24, 62% of patients achieved stable doses ≥10 mg BID. Median reductions in spleen volume and TSS were 24.2% and 43.8%, respectively. Thrombocytopenia necessitating dose reductions and dose interruptions occurred in 12 and 8 patients, respectively, and occurred mainly in patients with baseline platelet counts ≤75?×?10⁹/L. Seven patients experienced platelet count increases ≥15?×?10⁹/L. Mean hemoglobin levels remained stable over the treatment period. Two patients discontinued for adverse events: 1 for grade 4 retroperitoneal hemorrhage secondary to multiple and suspected pre-existing renal artery aneurysms and 1 for grade 4 thrombocytopenia.

Conclusions

Results suggest that a low starting dose of ruxolitinib with escalation to 10 mg BID may be appropriate in myelofibrosis patients with low platelet counts.

Trial registration

ClinicalTrials.gov:NCT01348490.

     

ALG/ATG treatment--a useful alternative for BMT in selected aplastic anaemia patients

8 patients with severe and 4 with non-severe aplastic anaemia, aged 7 to 46 years, whose suppressor lymphocyte activity was in most cases elevated and who had no histocompatible sibling donor, underwent 1-2 courses of ALG/ATG treatment. 6 patients got CR and 1 PR and during 1-4 years they live with sustaining haemopoiesis, independent of blood transfusion (except one in PR). Among these seven responders increased suppressor lymphocyte activity normalized in 6. The adverse effects of the treatment were granulocyto- and thrombocytopenia, subfebrile states, hepatotoxicity, serum sickness and skin allergy. Five patients died because of early or late complications of the treatment or it's failure. Our results, similar to other authors', are like after BMT and supports the immunological mechanism of A.A. Immunosuppressive treatment with ALG/ATG has many advantages: no need to have identical bone marrow donor, no GVHD, possibility of treatment of patients over 30, even pretreated with blood transfusions, and finally much lower costs and efforts.     

Intravenous immune globulin use in patients with human immunodeficiency virus-related thrombocytopenia who require dental extraction.

Five patients with human immunodeficiency virus (HIV)-related immune thrombocytopenia who were undergoing dental extraction were treated with intravenous immune globulin (IVIG). All patients received IVIG, 1 gram per kg, the day before the dental extraction and again the day of the dental extraction. Four patients had a previous history of minor clinical bleeding. The median baseline platelet count before extraction was 20 X 10(9) per liter (range 13 to 44). The median peak platelet count was 100 X 10(9) per liter (range 56 to 528) following infusion. This peak response was achieved by day 2 in 3 patients and by days 5 and 7 in 1 patient each. No patients had complications or toxicity from the infusions or perioperative bleeding. No patients required blood product transfusions for the surgical procedure. In conclusion, IVIG infusion should be considered in patients with HIV-related immune thrombocytopenia requiring surgical procedures when a prompt rise in platelet count is desired.     

补肾健脾化瘀法增强rHuEPO治疗肿瘤化疗后贫血疗效研究

目的:观察补肾健脾化瘀法联合基因重组的促红细胞生成素(rHuEPO)治疗中晚期恶性肿瘤化疗相关性贫血的临床疗效,以寻找进一步提高常规剂量的rHuEPO治疗恶性肿瘤贫血疗效的方法。方法:采用前瞻、随机、对照研究,将55例气血两虚型的恶性肿瘤化疗后贫血患者,随机分为研究组(A组)和对照组(B组),研究组给予补肾健脾方联合常规剂量的rHuEPO,对照组仅给予常规剂量的rHuEPO。记录治疗前及治疗后14日、28日、42日、56日时的血红蛋白(Hb)值,观察患者生活质量(QOL)改善情况和不良反应情况。结果:研究组与对照组患者的治疗后Hb、QOL与治疗前相比均有上升,研究组治疗贫血的有效率69.23%,而对照组为41.38%,两组疗效有统计学差异(X~2=4.29,p=0.04);发生促红细胞生成素抵抗的比例研究组与对照组有差异(P<0.05),并且在神疲气短、头晕眼花、纳呆消瘦等症状改善方面,研究组与对照组比较,更有优势,差异有统计学意义(P<0.05)。结论:健脾补肾化瘀法联合常规剂量的rHuEPO与单用rHuEPO相比,治疗气血两虚血瘀型恶性肿瘤患者化疗后贫血的疗效有进一步提高,发生促红细胞生成素抵抗的比例较低,且贫血症状改善更明显(P<0.05);表现出中医药疗法的优势,为化疗按时进行提供保障。     

Treatment of cancer-related anemia

Anemia with consequent tissue hypoxia is common problem in cancer patients. Developed via various patophysiological mechanisms, it has deleterious effect on quality of life and survival of patients with cancer. Recognition of symptoms and timely initiation of treatment improve patients' quality of life, as well as efficacy of oncological treatment. Red blood cells transfusions are well known and efficient way of anemia correction. They are "golden standard" in treatment of cancer-related anemia today, and are unavoidable in almost all patients with hemoglobin concentration below 80 g/L. Newest therapy guidelines in developed countries, supported by recent literature, encourage use of recombinant human erythropoietin (rHu-EPO), although detailed meta-analyses and prospective randomized clinical trials have shown that rHu-EPO decreases the need for transfusions in only 9-45% patients with cancer, only if they have mild anemia, rHu-EPO increases incidence of thromboembolic events, and suspicion arises that it supports tumor cells growth and multiplication. Therefore, it is necessary to define subgroups of patients which are best candidates for rHu-EPO therapy, to accomplish lower intensity of transfusion therapy.     

Subperitoneal hemorrhage

Clinical diagnosis of subperitoneal hemorrhage can be made in a substantial percentage of cases by recognition of a quite constant syndrome-provided the possibility of bleeding is considered. Progressive anemia, as indicated by repeated counts of erythrocytes in the blood or by hematocrit determinations, is confirmation of the diagnosis. The majority of patients recover spontaneously under conservative management.Surgical intervention is indicated if repeated episodes of hemorrhage occur or if the volume of circulating blood cannot be maintained by repeated transfusions of whole blood.     

Changes in erythropoiesis due to radiation or chemotherapy as studied by flow cytometric determination of peripheral blood reticulocytes

Flow cytometric determination of time dependent changes of numbers of reticulocytes in peripheral blood were investigated as a parameter for changes in erythropoiesis induced by radiation- or chemotherapy. Rats irradiated or treated with drugs (such as e.g. cyclophosphamide 100 mg/kg, vincristin 0.2 mg/kg, or mitomycin C 1.0 mg/kg) showed clear changes in erythropoietic activity. Reticulocyte numbers decreased rapidly until day 3-4 after treatment; this period was followed by a gradual increase and normal control values were seen at day 8-11. Radiation effects of doses as low 0.5 Gy could be detected in such a way. Similar studies were performed with patients with ovarian tumors treated with cis-platinum, a drug that may cause non-immune haemolysis. During prolonged treatment some patients showed increasing numbers of reticulocytes, measured at the first day of each hospitalization period, whereas leucocyte and platelet counts stayed more or less constant. Increasing numbers of reticulocytes generally indicates stimulation of erythropoietic activity of the bone marrow (due to increased blood loss); in this study increasing numbers often preceeded a decrease in hemoglobin values later on. Flow cytometric analysis of reticulocytes is therefore a potentially useful tool to detect changes in erythropoiesis, and considered more sensitive for the early recognition of patients that develop anemia, than hemoglobin measurements only.     

Use of mean platelet volume improves detection of platelet disorders

Classification of platelet disorders has been based on the platelet count. Addition of a second variable, mean platelet volume (MPV), to the routine blood count allows classification of patients into 9 categories: high, low, or normal MPV, and high, low or normal platelet count. We studied 1,244 adult inpatients. 1,134 had both platelet values normal. 11 patients had high MPV and low platelet count: all had hyperdestructive causes. 15 patients had high MPV and normal platelet count: 12 had heterozygous thalassemia, and three had iron deficiency. Seven patients had high MPV and high platelet count: causes included myeloproliferative disorders, inflammation, iron deficiency, and splenectomy, 25 patients had high platelet counts and normal MPV: the causes were inflammation, infection, sickle cell anemia, iron deficiency, or chronic myelogenous leukemia. 52 patients had an MPV that was inappropriately low for the platelet count (high, normal, or low). All had sepsis, splenomegaly, aplastic anemia, chronic renal failure, or a disease being treated with myelosuppressive drugs. High MPV thus appears correlated with myeloproliferative disease or thalassemia; and low MPV, with cytotoxic drugs or marrow hypoplasia. Addition of MPV to the platelet count allows subtler disorders to be detected (when the platelet count is normal), and allows distinction of the cause of thrombocytopenia.     

Changes in erythropoiesis due to radiation or chemotherapy as studied by flow cytometric determination of peripheral blood reticulocytes

Summary Flow cytometric determination of time dependent changes of numbers of reticulocytes in peripheral blood were investigated as a parameter for changes in erythropoiesis induced by radiation- or chemotherapy. Rats irradiated or treated with drugs (such as e.g. cyclo-phosphamide 100 mg/kg, vincristin 0.2 mg/kg, or mitomycin C 1.0 mg/kg) showed clear changes in erythropoietic activity. Reticulocyte numbers decreased rapidly until day 3–4 after treatment; this period was followed by a gradual increase and normal control values were seen at day 8–11. Radiation effects of doses as low 0.5 Gy could be detected in such a way.Similar studies were performed with patients with ovarian tumors treated with cis-platinum, a drug that may cause non-immune haemolysis. During prolonged treatment some patients showed increasing numbers of reticulocytes, measured at the first day of each hospitalization period, whereas leucocyte and platelet counts stayed more or less constant. Increasing numbers of reticulocytes generally indicates stimulation of erythropoietic activity of the bone marrow (due to increased blood loss); in this study increasing numbers often preceeded a decrease in hemoglobin values later on.Flow cytometric analysis of reticulocytes is therefore a potentially useful tool to detect changes in erythropoiesis, and considered more sensitive for the early recognition of patients that develop anemia, than hemoglobin measurements only.In honous of Prof. P. van Duijn.     

Cotton-top tamarins (Saguinus oedipus oedipus): Hematologic reference values and hemopathologic responses

Hematologic reference values have been established for captive adult cotton-top tamarins (Saguinus oedipus oedipus) by carrying out full blood counts and fibrinogen estimation on 43 clinically normal animals. Females were shown to have significantly lower hemoglobin levels, red cell counts and packed cell volumes, and higher reticulocyte counts than males. The reference values were used to identify abnormal changes in the blood of 13 clinical cases. Marked neutrophilia was found in animals with localized bacterial infections, and a degenerative left shift was recorded in an individual with streptococcal septicemia. Three cases of unexplained progressive muscle wasting showed Heinz body anemia and abnormal white cell changes. These hematologic responses have been compared where possible with those recorded in other species of Callithricidae.     

Regulation of iron absorption in hemoglobinopathies

Beta-thalassemia and sickle cell anemia (SCD) represent the most common hemoglobinopathies caused, respectively, by deficient production or alteration of the beta chain of hemoglobin (Hb). Patients affected by the most severe form of thalassemia suffer from profound anemia that requires chronic blood transfusions and chelation therapies to prevent iron overload. However, patients affected by beta-thalassemia intermedia, a milder form of the disease that does not require chronic blood transfusions, eventually also show elevated body iron content due to increased gastrointestinal iron absorption. Even SCD patients might require blood transfusions and iron chelation to prevent deleterious and painful vaso-occlusive crises and complications due to iron overload. Although definitive cures are presently available, such as bone marrow transplantation (BMT), or are in development, such as correction of the disease through hematopoietic stem cell beta-globin gene transfer, they are potentially hazardous procedures or too experimental to provide consistently safe and predictive clinical outcomes. Therefore, studies that aim to better understand the pathophysiology of the hemoglobinopathies might provide further insight and new drugs to dramatically improve the understanding and current treatment of these diseases. This review will describe how recent discoveries on iron metabolism and erythropoiesis could lead to new therapeutic strategies and better clinical care of these diseases, thereby yielding a much better quality of life for the patients.     

Hemoglobinopathies in the Hamilton region. II. Thalassemia traits and iron therapy.

Between July 1973 and July 1974 all adult patients with hypochromic anemia and a mean corpuscular volume of 75 mum3 or less were screened for hemoglobinopathies. Of the 490 patients 105 had beta-thalassemia trait, 11 had alpha1-thalassemia trait, 4 had hemoglobin Lepore trait and 1 had hemoglobin H disease. Of 48 inpatients whose charts were reviewed 19 had been on oral iron therapy and 7 of them had been given iron intramuscularly. Of 27 outpatients interviewed 10 had been on intermittent iron therapy for 18 months or more; 4 had been given at least 1 g of intramuscular iron. Iron deficiency was not documented in any of these patients. Iron deficiency should be diagnosed by means other than the presence of a hypochromic picture in the peripheral blood before iron therapy is instituted, particularly in communities with a large population of Mediterranean or South-East Asian origin.     

Heparin-associated thrombocytopenia: low frequency in 104 patients treated with heparin of intestinal mucosal origin.

A prospective study of 104 patients receiving heparin obtained from porcine intestinal mucosa for 4 or more days was conducted to determine the frequency of associated significant thrombocytopenia (platelet count less than 100 x 10(9)/I on 2 consecutive days). No episodes of significant thrombocytopenia were identified in the 13 patients receiving heparin by continuous intravenous infusion for a mean of 8.0 days or in the 38 patients receiving heparin subcutaneously for a mean of 9.9 days. In 1 of the 26 patients receiving heparin as intermittent intravenous boluses for a mean of 8.2 days significant thrombocytopenia developed; this patient had laboratory evidence of disseminated intravascular coagulation. In none of the 17 patients receiving uninterrupted heparin therapy for 4 or more days by more than one route of administration but for less than 4 days by any single route did significant heparin-associated thrombocytopenia develop. Of the 104 patients 13 had one or more platelet counts of less than 150 x 10(9)/I, but in most it was not possible to definitely relate the thrombocytopenia to the heparin therapy. Platelets in normal platelet-rich plasma did not aggregate when heparin and serum from patients with thrombocytopenia were added. The frequency of heparin-associated thrombocytopenia noted in this study was considerably lower than that reported previously.     

Refractory Sideroblastic and Nonsideroblastic Anemia: A Review of 27 Cases

A study was done with 27 patients who met the following criteria: (1) anemia, (2) cellular bone marrow not diagnostic of leukemia, (3) absence of underlying disease that could account for the hematologic abnormalities at time of initial study and (4) absence of iron, B₁₂ or folate deficiency.Of the 27 patients, 13 had ringed sideroblasts and 14 did not. Eleven patients received corticosteroids, 18 received folate, 23 pyridoxine and 12 androgens. Two partial responses occurred in the sideroblastic group and were attributed to androgen therapy in one patient and pyridoxine therapy in the other. In the nonsideroblastic group, two partial responses occurred which were attributed to prednisone therapy. Transfusions were required in 23 patients. Leukemia developed in six patients.It is concluded that currently used treatments have little effect on refractory anemia and that in most patients continuing transfusions are required. In a small percentage of patients, there is transformation to leukemia.     

Erythropoietic protein supportive treatment in small cell lung cancer

Anemia is common among patients with malignant tumors, due to the disease and chemotherapy. Anemia decreases patient's quality of life, and worsens the dose intensity of chemotherapy. The aim of this retrospective data-analysis was to determine the rate of transfusions and the maintenance of chemotherapeutic dose intensity in 9 small cell lung cancer patients receiving beta-erythropoietin, due to anemia observed after the first cycle of chemotherapy. The mean pre-treatment hemoglobin concentration of the patients was 116.67+/-8.17 g/L (mean+/-SD). The mean pre-erythropoietin hemoglobin concentration at baseline was 103.11+/-7.52 g/L. Six cycles of platinum compounds and etoposide were used. The post-treatment hemoglobin concentration of patients was 110.11+/-5.37 g/L (p = 0,028 vs. baseline). During these 54 chemotherapeutic cycles, only 2 patients needed transfusion, each of them once. According to our experience, the use of beta-erythropoietin in 9 anemic small cell lung cancer patients resulted in a low rate of transfusions and maintenance of cytotoxic treatment dose intensity. The adequate use of beta-erythropoietin is of great help to the physician in the management of small cell lung cancer patients.