Prophylactic tranexamic acid (TXA) did not decrease World Health Organization (WHO) grade ≥2 bleeding incidence or rates of platelet or red blood cell (RBC) transfusions in patients with thrombocytopenia associated with treatment of hematologic malignancy, according to a study published in Blood.
Evidence to support the use of prophylactic TXA for thrombocytopenia is lacking, though there is evidence that the medication decreases bleeding and need for transfusions in surgical patients, said corresponding author Terry B. Gernsheimer, MD, of the University of Washington School of Medicine. To evaluate the efficacy of prophylactic TXA to reduce bleeding in patients undergoing treatment for hematologic malignancies, researchers conducted a multicenter, randomized, double-blind, placebo-controlled clinical trial, dubbed A-TREAT.
Dr. Gernsheimer and colleagues enrolled 330 patients undergoing chemotherapy, immuno-therapy, or hematopoietic cell transplant (HCT) for hematologic malignancies or aplasia. Eligible patients were also anticipated to have hypoproliferative thrombocytopenia resulting in a platelet count of <10,000/µL for five days or more.
When platelet counts fell below 50,000/µL, patients were randomized to receive TXA or placebo. Subsequently, when platelet counts fell below 30,000/µL, patients moved into the treatment phase to receive either oral 1.3 g or intravenous 1.0 g TXA or placebo every 8 hours. Patients also received a prophylactic platelet transfusion when their platelet counts fell below 10,000/µL or at their doctor’s discretion.
A-TREAT included the following outcomes:
- Primary outcome: incidence of WHO grade ≥2 bleeding during the first 30 days after activation
- Secondary outcomes: number of platelet transfusions and number of days alive without WHO grade ≥2 bleeding, both within the first 30 days after activation
- Exploratory outcomes for alternative measures of bleeding: number of days with bleeding/thrombocytopenia, time from activation to first episode of WHO grade ≥2 bleeding or death, highest grade of bleeding, and death ascribed to bleeding, all within the first 30 days after activation
- Exploratory outcomes for alternative measures of transfusion frequency: number of platelet or RBC transfusions per subject by thrombocytopenic day during the first 30 days after activation, survival at least 30 days post-activation without a platelet or RBC transfusion, and number of patients with platelet count >10,000/µL over the study period of 30 days from activation.
Out of 330 patients, primary outcome data were obtained for 145 patients in the TXA group and 144 in the placebo group and observed in 50.3% and 54.2% of the groups, respectively. For the remaining patients in each respective group (20 in TXA and 21 in placebo), data were multiply imputed. Results showed an odds ratio of WHO grade ≥2 bleeding of 0.83 (95% CI 0.50-1.34; p=0.44) within the first 30 days after activation.
The median number of platelet transfusions during the specified time was 7.7 and 7.6 for the TXA and placebo arms, respectively, with a mean difference of 0.07 (95% CI -1.90-2.04; p=0.95). The median number of days alive without WHO grade ≥2 bleeding was 28.1 and 27.7, respectively, with a mean difference of 0.79 (95% CI -0.40-1.98; p=0.19); and the median number of RBC transfusions per thrombocytopenic day was 0.4 in both groups, with a mean difference of 0.03 (95% CI -0.06-0.12; p=0.50). The remaining outcomes were similar between the two groups.
“The negative results of this study were unexpected,” Dr. Gernsheimer said. “TXA and another antifibrinolytic agent, epsilon aminocaproic acid, are commonly used to prevent and treat bleeding in patients with hematologic malignancies. It appears the mechanism of bleeding and its prevention are different than in surgical bleeding in these patient populations.”
Adverse events were similar between the TXA and placebo groups, as were thrombotic events (3.7% vs. 5.5%), veno-occlusive disease (1.8% vs. 1.2%), and visual changes including new colorblindness (5% of patients), and newly abnormal Amsler grid exams (10% of patients). However, patients in the TXA group had more central line occlusions than those in the placebo group (16.6% vs. 6.7%).
“Based on the results of this study, we recommend against routine use of antifibrinolytic therapy to prevent bleeding in thrombocytopenic patients undergoing therapy for hematologic malignancies, a common practice at some centers,” Dr. Gernsheimer said.
She added that this study did not address specific subgroups of patients such as those refractory to platelet transfusion, whether TXA might be helpful in an ongoing bleed, or in patients with other causes of thrombocytopenia.
Any conflicts of interest declared by the authors can be found in the original article.
Gernsheimer TB, Brown SP, Triulzi DJ, et al. Prophylactic tranexamic acid in patients with hematologic malignancy: a placebo controlled, randomized clinical trial [published online ahead of print, 2022 June 6]. Blood. doi: 10.1182/blood.2022016308.