Tranexamic acid therapy in acute myeloid leukemia: possible reduction of platelet transfusions

Prophylaxis with low dose tranexamic acid in acute myeloid leukemia patients undergoing intensive chemotherapy

Patients suffering from acute myeloid leukemia (AML) carry a high risk of serious bleeding complications due to severe thrombocytopenia for long periods of time during treatment. Prior to prophylactic platelet transfusion becoming the standard of care, intracranial bleeding was a major contributor to death in AML patients. However, despite prophylactic platelet transfusions, up to 79% of patients with AML experience clinically significant bleeding during treatment. Antifibrinolytics are effective and well tolerated hemostatic agents widely used in many patient groups, and in this study, we investigated the effect of low dose tranexamic acid (TXA) in patients with AML and thrombocytopenia. We compared bleeding and thrombosis between 113 thrombocytopenic AML patients receiving TXA 500 mg three times daily (n = 36) versus no-TXA (n = 77). Clinical information was obtained systematically from electronic medical records, and laboratory data were collected from the laboratory information system. No difference was demonstrated in number of patients with at least one bleeding episode (TXA: 89% vs. no-TXA: 93%, p = 0.60), median number of bleeding days (TXA: 2.5 days vs. no-TXA 2.0 days, p = 0.30), bleeding location or transfusion needs between the two groups. However, platelet count was found to be a significant risk factor for bleeding, with a probability of bleeding of 35% with a platelet count below 5 × 109/L (logistic regression, p < 0.01). We found no difference in thromboembolic events between the two groups (TXA: 8% vs. no-TXA 10%, p = 0.99). In conclusion, treatment with low dose TXA is safe, but we found no evidence to suggest that it reduces bleeding in AML patients with thrombocytopenia.

Challenges and Advances in Managing Thrombocytopenic Cancer Patients

Cancer patients have varying incidence, depth and duration of thrombocytopenia. The mainstay of managing severe chemotherapy-induced thrombocytopenia (CIT) in cancer is the use of platelet transfusions. While prophylactic platelet transfusions reduce the bleeding rate, multiple unmet needs remain, such as high residual rates of bleeding, and anticancer treatment dose reductions/delays. Accordingly, the following promising results in other settings, antifibrinolytic drugs have been evaluated for prevention and treatment of bleeding in patients with hematological malignancies and solid tumors. In addition, Thrombopoeitin receptor agonists have been studied for two major implications in cancer: treatment of severe thrombocytopenia associated with myelodysplastic syndrome and acute myeloid leukemia; primary and secondary prevention of CIT in solid tumors in order to maintain dose density and intensity of anti-cancer treatment. Furthermore, thrombocytopenic cancer patients are often prescribed antithrombotic medication for indications arising prior or post cancer diagnosis. Balancing the bleeding and thrombotic risks in such patients represents a unique clinical challenge. This review focuses upon non-transfusion-based approaches to managing thrombocytopenia and the associated bleeding risk in cancer, and also addresses the management of antithrombotic therapy in thrombocytopenic cancer patients.

Management of hemostatic complications in acute leukemia: Guidance from the SSC of the ISTH

Patients with acute leukemia frequently develop thrombocytopenia and hemostatic complications caused by coagulopathy. Coagulopathy complicates the management of these patients and can lead to significant morbidity and mortality. This guidance document aims to review and provide guidance on the management of hemostatic complications in adult patients with acute leukemia, addressing four main issues, including platelet transfusion, disseminated intravascular coagulation, L-asparaginase-related hypofibrinogenemia, and the use of antifibrinolytic agents.

How to Use a Prioritised Approach for Treating Hematological Disorders During the COVID-19 Pandemic in India?

The current pandemic coronavirus, SARS-CoV-2, is known to cause severe infection (COVID-19) in patients with comorbidities, particularly cancer or an immunosuppressed state. Most healthcare systems in the country are likely to be overwhelmed soon if the pandemic moves to a stage of community transmission. Currently, limited evidence is available for managing patients with hematological disorders during the COVID-19 pandemic. The current review summarises the possible challenges clinicians are likely to face, key considerations to guide decision making, and possible solutions to the anticipated challenges. Disease specific recommendations and possible guidance for decision making have been suggested for most hematologic diseases that are feasible in our health setup. It is not meant to replace individual clinical judgment, but to provide a template to formulate local policies.

Caring for AML Patients During the COVID-19 Crisis: An American and Italian Experience

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the subsequent pandemic have impacted every aspect of oncology care worldwide. Healthcare systems have been forced to rapidly change practices in order to maximize the safety of patients and healthcare providers and preserve scare resources. Patients with acute myeloid leukemia are at increased risk of complications from SARS-CoV-2 not only due to immune compromise related to the malignancy but also due to the acuity of the disease and intensity of treatment. These issues have created unique challenges during this difficult time. In this article, we present the approaches taken by two groups of hematologist/oncologists, one in the United States and one in Italy, who have been caring for acute myeloid leukemia (AML) patients in the face of the pandemic.

The many roles of tranexamic acid: An overview of the clinical indications for TXA in medical and surgical patients

Clinically significant bleeding can occur as a consequence of surgery, trauma, obstetric complications, anticoagulation, and a wide variety of disorders of hemostasis. As the causes of bleeding are diverse and not always immediately apparent, the availability of a safe, effective, and non-specific hemostatic agent is vital in a wide range of clinical settings, with antifibrinolytic agents often utilized for this purpose. Tranexamic acid (TXA) is one of the most commonly used and widely researched antifibrinolytic agents; its role in postpartum hemorrhage, menorrhagia, trauma-associated hemorrhage, and surgical bleeding has been well defined. However, the utility of TXA goes beyond these common indications, with accumulating data suggesting its ability to reduce bleeding and improve clinical outcomes in the face of many different hemostatic challenges, without a clear increase in thrombotic risk. Herein, we review the literature and provide practical suggestions for clinical use of TXA across a broad spectrum of bleeding disorders.

The use of antifibrinolytics in pediatric patients with hypoproliferative thrombocytopenia

Despite the use of evidence-based platelet transfusion therapy during periods of hypoproliferative thrombocytopenia, a large proportion of pediatric hematology/oncology patients continue to suffer from clinically significant bleeding. Antifibrinolytic (AF) drugs have been shown in certain surgical and trauma settings to decrease bleeding, blood transfusion, and improve survival. We conducted a retrospective assessment of the safety of using AF drugs in pediatric patients with hypoproliferative thrombocytopenia at our center as well as the impact on bleeding occurrence and severity.

Antifibrinolytics (lysine analogues) for the prevention of bleeding in people with haematological disorders

BACKGROUND

People with haematological disorders are frequently at risk of severe or life-threatening bleeding as a result of thrombocytopenia (reduced platelet count). This is despite the routine use of prophylactic platelet transfusions to prevent bleeding once the platelet count falls below a certain threshold. Platelet transfusions are not without risk and adverse events may be life-threatening. A possible adjunct to prophylactic platelet transfusions is the use of antifibrinolytics, specifically the lysine analogues tranexamic acid (TXA) and epsilon aminocaproic acid (EACA). This is an update of a Cochrane review first published in 2013.

OBJECTIVES

To determine the efficacy and safety of antifibrinolytics (lysine analogues) in preventing bleeding in people with haematological disorders.

SEARCH METHODS

We searched for randomised controlled trials (RCTs) in the Cochrane Central Register of Controlled Trials (The Cochrane Library 2016, Issue 3), MEDLINE (from 1946), Embase (from 1974), CINAHL (from 1937), the Transfusion Evidence Library (from 1950) and ongoing trial databases to 07 March 2016.

SELECTION CRITERIA

We included RCTs involving participants with haematological disorders, who would routinely require prophylactic platelet transfusions to prevent bleeding. We only included trials involving the use of the lysine analogues TXA and EACA.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened all electronically-derived citations and abstracts of papers, identified by the review search strategy, for relevancy. Two review authors independently assessed the full text of all potentially relevant trials for eligibility, completed the data extraction and assessed the studies for risk of bias using The Cochrane Collaboration's 'Risk of bias' tool. We requested missing data from one author but the data were no longer available. The outcomes are reported narratively: we performed no meta-analyses because of the heterogeneity of the available data.

MAIN RESULTS

We identified three new studies in this update of the review. In total seven studies were eligible for inclusion, three were ongoing RCTs and four were completed studies. The four completed studies were included in the original review and the three ongoing studies were included in this update. We did not identify any RCTs that compared TXA with EACA.Of the four completed studies, one cross-over TXA study (eight participants) was excluded from the outcome analysis because it had very flawed study methodology. Data from the other three studies were all at unclear risk of bias due to lack of reporting of study methodology.Three studies (two TXA (12 to 56 participants), one EACA (18 participants) reported in four articles (published 1983 to 1995) were included in the narrative review. All three studies compared the drug with placebo. All three studies included adults with acute leukaemia receiving chemotherapy. One study (12 participants) only included participants with acute promyelocytic leukaemia. None of the studies included children. One of the three studies reported funding sources and this study was funded by a charity.We are uncertain whether antifibrinolytics reduce the risk of bleeding (three studies; 86 participants; very low-quality evidence). Only one study reported the number of bleeding events per participant and there was no difference in the number of bleeding events seen during induction or consolidation chemotherapy between TXA and placebo (induction; 38 participants; mean difference (MD) 1.70 bleeding events, 95% confidence interval (CI) -0.37 to 3.77: consolidation; 18 participants; MD -1.50 bleeding events, 95% CI -3.25 to 0.25; very low-quality evidence). The two other studies suggested bleeding was reduced in the antifibrinolytic study arm, but this was statistically significant in only one of these two studies.Two studies reported thromboembolism and no events occurred (68 participants, very low-quality evidence).All three studies reported a reduction in platelet transfusion usage (three studies, 86 participants; very low-quality evidence), but this was reported in different ways and no meta-analysis could be performed. No trials reported the number of platelet transfusions per participant. Only one study reported the number of platelet components per participant and there was a reduction in the number of platelet components per participant during consolidation chemotherapy but not during induction chemotherapy (consolidation; 18 participants; MD -5.60 platelet units, 95% CI -9.02 to -2.18: induction; 38 participants, MD -1.00 platelet units, 95% CI -9.11 to 7.11; very low-quality evidence).Only one study reported adverse events of TXA as an outcome measure and none occurred. One study stated side effects of EACA were minimal but no further information was provided (two studies, 74 participants, very low-quality evidence).None of the studies reported on the following pre-specified outcomes: overall mortality, adverse events of transfusion, disseminated intravascular coagulation (DIC) or quality of life (QoL).

AUTHORS' CONCLUSIONS

Our results indicate that the evidence available for the use of antifibrinolytics in haematology patients is very limited. The trials were too small to assess whether or not antifibrinolytics decrease bleeding. No trials reported the number of platelet transfusions per participant. The trials were too small to assess whether or not antifibrinolytics increased the risk of thromboembolic events or other adverse events. There are three ongoing RCTs (1276 participants) due to be completed in 2017 and 2020.

Aminocaproic acid use in hospitalized patients with hematological malignancy: a case series

The antifibrinolytic aminocaproic acid is widely used in surgical settings to prevent blood loss and decrease transfusion requirements, and small observational studies have suggested that aminocaproic acid may be useful in the setting of malignancy-related bleeding. At our institution, aminocaproic acid is sometimes prescribed to patients with hematological malignancy who experience refractory thrombocytopenia with or without bleeding. We performed a 5-year retrospective review of 54 adult patients with 13 types of hematological malignancy who received aminocaproic acid at our institution. Indications for use included 31 (57.4%) for refractory thrombocytopenia with bleeding, 16 (29.6%) for refractory thrombocytopenia without bleeding, and 7 (13%) for bleeding alone. Patients received both oral and intravenous formulations. Administered doses ranged broadly and median duration of use was 6 days. Three patients (5.7%) developed deep venous thrombosis but none of the thrombotic events were clearly related to administration of aminocaproic acid. We conclude that aminocaproic acid may be a relatively safe and cost-effective adjunct treatment in the setting of bleeding related to the diagnosis and treatment of hematological malignancy. Prospective trials as well as formalized protocols for the use of aminocaproic acid may be indicated. Copyright © 2015 John Wiley & Sons, Ltd.

Antifibrinolytics (lysine analogues) for the prevention of bleeding in patients with haematological disorders

BACKGROUND

Patients with haematological disorders are frequently at risk of severe or life-threatening bleeding as a result of thrombocytopenia. This is despite the routine use of prophylactic platelet transfusions (PlTx) to prevent bleeding once the platelet count falls below a certain threshold. PlTx are not without risk and adverse events may be life-threatening. A possible adjunct to prophylactic PlTxs is the use of antifibrinolytics, specifically the lysine analogues tranexamic acid (TXA) and epsilon aminocaproic acid (EACA).

OBJECTIVES

To determine the efficacy and safety of antifibrinolytics (lysine analogues) in preventing bleeding in patients with haematological disorders.

SEARCH METHODS

We searched for randomised controlled trials (RCTs) in the Cochrane Central Register of Controlled Trials (CENTRAL Issue 12, 2012), MEDLINE (1948 to 10 January 2013), EMBASE (1980 to 10 January 2013), CINAHL (1982 to 10 January 2013), PubMed (e-publications only) and the Transfusion Evidence Library (1980 to January 2013). We also searched several international and ongoing trial databases to 10 January 2013 and citation-tracked relevant reference lists.

SELECTION CRITERIA

RCTs involving patients with haematological disorders, who would routinely require prophylactic platelet transfusions to prevent bleeding. We only included trials involving the use of the lysine analogues TXA and EACA.

DATA COLLECTION AND ANALYSIS

Two authors independently screened all electronically derived citations and abstracts of papers, identified by the review search strategy, for relevancy. Two authors independently assessed the full text of all potentially relevant trials for eligibility, completed the data extraction and assessed the studies for risk of bias using The Cochrane Collaboration's 'Risk of bias' tool. We requested missing data from one author but the data were no longer available. The outcomes are reported narratively: we performed no meta-analyses because of the heterogeneity of the available data.

MAIN RESULTS

Of 470 articles initially identified, 436 were excluded on the basis of the title and abstract. We reviewed 34 full-text articles from which four studies reported in five articles were eligible for inclusion. We did not identify any RCTs which compared TXA with EACA. We did not identify any ongoing RCTs.One cross-over TXA study (eight patients) was excluded from the outcome analysis because data from this study were at a high risk of bias. Data from the other three studies were all at unclear risk of bias due to lack of reporting of study methodology.Three studies (two TXA (12 to 56 patients), one EACA (18 patients)) reported in four articles (published 1983 to 1995) were included in the narrative review. All three studies compared the drug with placebo.All studies reported bleeding, but it was reported in different ways. All three studies suggested antifibrinolytics reduced the risk of bleeding. The first study showed a difference in average bleeding score of 42 in placebo (P) versus three (TXA). The second study only showed a difference in bleeding episodes during consolidation chemotherapy, with a mean of 2.6 episodes/patient (standard deviation (SD) 2.2) (P) versus a mean of 1.1 episodes/patient (SD 1.4) (TXA). The third study reported bleeding on 50% of days at risk (P) versus bleeding on 31% of days at risk (EACA).Two studies (68 patients) reported thromboembolism and no events occurred.All three studies reported a reduction in PlTx usage. The first study reported a difference of 222 platelet units (P) versus 69 platelet units (TXA). The second study only showed a difference in total platelet usage during consolidation chemotherapy, with a mean of 9.3 units (SD 3.3) (P) versus 3.7 (SD 4.1) (TXA). The third study reported one PlTx every 10.5 days at risk (P) versus one PlTx every 13.3 days at risk (EACA).Two studies reported red cell transfusion requirements and one study found a reduction in red cell transfusion usage.One study reported death due to bleeding as an outcome measure and none occurred.Only one study reported adverse events of TXA as an outcome measure and none occurred.None of the studies reported on the following pre-specified outcomes: overall mortality, adverse events of transfusion, disseminated intravascular coagulation (DIC) or quality of life (QoL).

AUTHORS' CONCLUSIONS

Our results indicate that the evidence available for the use of antifibrinolytics in haematology patients is very limited. The only available data suggest that TXA and EACA may be useful adjuncts to platelet transfusions so that platelet use, and the complications associated with their use, can be reduced. However, the trials were too small to assess whether antifibrinolytics increased the risk of thromboembolic events. Large, high-quality RCTs are required before antifibrinolytics can be demonstrated to be efficacious and safe in widespread clinical practice.

Platelet dose for prophylactic platelet transfusions

Although guidelines exist to deal with some aspects of platelet transfusion practice, many important clinical issues have not been addressed in large randomized controlled trials (RCTs). Slichter et al. conducted a RCT of prophylactic platelet transfusions to determine the effects of the dose of platelets on clinical signs of bleeding, the use of platelet and red cell transfusions, changes in the recipient's post-transfusion platelet count, days to next transfusion and adverse events (Effects of Prophylactic Platelet Dose on Transfusion Outcomes [PLADO] trial). The primary end point of the study (i.e., the percentage of patients in each group with at least one episode of bleeding of grade 2 or higher according to the WHO criteria) was not significantly different (71, 69 and 70% of patients in the low-, medium- and high-dose group, respectively). According to these data, one can conclude that the dose of platelets transfused has no significant effect on the incidence of bleeding in patients with hypoproliferative thrombocytopenia and platelet counts no greater than 10 × 10⁹/l.

Algorithm for managing the platelet refractory patient

Refractoriness to platelet transfusions continues to be a major problem for many thrombocytopenic patients. A proposed algorithm for managing these patients is presented which proceeds from easily instituted changes in platelet transfusion therapy such as provision of ABO-compatible and "fresh" platelet transfusions to the more difficult and costly process of selecting compatible platelets for patients who are documented to be alloimmunized. For nonimmunized platelet refractory recipients, multiple clinical and drug factors that may adversely effect transfusion responses have been identified. Identifying which of these factors are causally associated with poor platelet responses in any given patient remains a substantial challenge.

Menorrhagia in von Willebrand disease successfully treated with single daily dose tranexamic acid

Four cases of menorrhagia in von Willebrand disease were successfully treated with tranexamic acid given in a single daily dose of 4 g for the first 3-5 days of the menstrual cycle. The pathophysiology and pharmacokinetics are discussed. The apparent improved efficacy and acceptability of this new dosing regime have been highlighted.

Tranexamic acid in oncology

Tranexamic acid has the potential to be a pharmacologic adjunct for the prophylaxis of hemorrhagic complications occurring in the oncology population. The studies and cases reviewed here suggest that tranexamic acid administration may be a therapeutic option for bleeding prophylaxis in APL where enhanced fibrinolysis accompanies the disease state. Because of the lack of a control in these reports, and the small sample size, it is not possible to extrapolate these conclusions regarding the efficacy of tranexamic acid in preventing hemorrhage in the larger thrombocytopenic oncology population. However, these reports concluded that its administration is safe, with few adverse effects and no thromboembolic events noted. A large, well-designed, controlled clinical trial is needed before a recommendation for the routine use of tranexamic acid in the oncology population can be established.

A controlled trial of tranexamic acid therapy for the reduction of bleeding during treatment of acute myeloid leukemia

In order to determine the efficacy of the antifibrinolytic agent tranexamic acid (TA) in reducing bleeding and platelet transfusions during the treatment of acute myeloid leukemia (AML), we conducted a randomized placebo-controlled double-blind study. Patients with AML undergoing induction or postremission consolidation chemotherapy were randomized into TA or placebo groups. Patients were not given platelet transfusions prophylactically but only when bleeding occurred. The severity of any bleeding event was scored. Thirty eight patients were randomized during induction. There were no significant differences between the two groups in the number of bleeding events and their severity or in the number of platelet transfusions given. Eighteen patients were studied during consolidation. In contrast, to the induction period, during consolidation there was a significantly less severe bleeding tendency in the TA group resulting in a lower platelet transfusion requirement [3.7 +/- 4.1 vs. 9.3 +/- 3.3 platelet units (p < .05)]. TA was well tolerated and no side effects were seen and no specific thromboembolic events were noticed. We conclude that giving TA during the thrombocytopenic period of AML patients undergoing consolidation chemotherapy is beneficial and safely reduces platelet transfusions.

Disseminated intravascular coagulation (DIC) in adult patients with acute leukaemia

In 71 patients with acute leukaemia admitted for remission induction, disseminated intravascular coagulation (DIC) was looked for in 50 patients and diagnosed in 10 (20%). Of 10 patients with acute lymphoblastic leukaemia, 3 had DIC, and of 40 patients with acute myeloblastic leukaemia, 7 had DIC. The presence of DIC was related to bleeding manifestations within the first 2 weeks. A haemorrhagic diathesis was present in all DIC patients: 4 had minor and 6 had major bleeding, i.e. WHO grade > or = 2. In addition to blood product support, most DIC patients were treated with low doses of heparin and tranexamic acid. In all DIC patients the haemorrhagic symptoms preceded the heparin administration. Among 40 screened patients without DIC, 17 patients had minor and 3 had major haemorrhagic manifestations. Thus, the proportion of patients with major bleeding was significantly greater among the DIC patients (6/10 vs 3/40, p < 0.001). In conclusion, DIC at presentation was associated with a significantly increased risk for severe haemorrhagic complications and should be looked for in adults with acute leukaemia.

Persistence of plasmin-mediated pro-urokinase activation on the surface of human monocytoid leukemia cells in vitro

Human leukemia cell lines, unlike those from adherent tumors, have been shown to continuously activate the pro-urokinase (pro-u-PA) they produce. In the present study we found that, in normal cell-culture conditions in 10% FCS the plasminogen activation cascade works continuously on monocytoid leukemia cells, which expressed plasmin activity and active u-PA on their cell surface. This plasmin catalyzed the conversion of the produced pro-u-PA to active 2-chain urokinase (tcu-PA), and was derived from bovine serum plasminogen by the activity of cell-bound tcu-PA. Plasmin generation was abolished and pro-u-PA accumulated in cell cultures that were grown for several days, either in the presence of serum thoroughly depleted of plasminogen, or in the presence of 1 mM tranexamic acid. Plasmin generated on the cell surface was found to be present in 2 enzymatically active fragments, of M(r) 85,000 and M(r) 50,000, which were slowly released into the growth medium. These fragments could activate pro-u-PA in serum-free growth medium. Most of the bound plasmin could be washed off cells with 10 mM tranexamic acid, but complete removal of plasmin from the cell surface required washing of the cells with acid-glycine pH 3.0.