Still, there was no significant difference between the two groups in time to recovery from thrombocytopenia or a range of other outcomes including number of days in hospital or adverse events, Dr. Stanworth said.
Serious grade 3 or 4 bleeds occurred in one patient in the prophylaxis group (0.3%) and six in the no-prophylaxis group (2%). The difference did not reach statistical significance, but represents a sixfold increase in these sometimes life-threatening events (odds ratio 6.05; P = .13).
One intracranial bleed occurred in the no-prophylaxis group. Only two of the seven patients had a platelet count below 10x109/L at the onset of grade 3-4 bleeding, and both were receiving induction chemotherapy for AML, he said.
During a discussion of the results, an audience member described the difference in bleeding between subgroups as remarkable, and suggested that AML patients should be taken far more seriously with regard to platelet prophylaxis because they may be especially predisposed to serious bleeding events because of endothelial damage during therapy. Dr. Stanworth concurred.
In his conclusion, Dr. Stanworth said there is clearly a need for new strategies to minimize the high burden of bleeding, and suggested that antifibrinolytics and the role of tranexamic acid should be explored.
For his part, Dr. Dzik said, "We need to stop approaching all patients as if they were the same and develop a risk score to identify those patients at higher risk of bleeding. The first question on the score will be ‘Are you an autologous stem cell case?’ and then tailor the degree of hemostatic support to match the risk of the patient."
TOPPS was funded by the National Health Service Blood and Transplant. Dr. Stanworth and Dr. Dzik reported no disclosures.