Therapeutic instead of prophylactic platelet transfusions are safe,
feasible, and would reduce costs considerably, say German
researchers reporting the first worldwide randomized study comparing
the 2 different strategies. However, the study was conducted in 171
patients, and experts believe more data are needed before
conclusions can be drawn about safety and the new strategy is
implemented.

The trial was presented here at the American Society of Hematology
(ASH) 50th Annual Meeting and Exposition by Hannes Wandt, MD, from
the Klinikum Nuremberg Nord, in Nuremberg, Germany. It was conducted
in patients who had recently received high-dose chemotherapy, total-
body irradiation, or autologous stem-cell transplant for a variety
of hematological malignancies, including multiple myeloma, non-
Hodgkin's lymphoma, Hodgkin's disease, and acute myeloid leukemia.

Such patients often become thrombocytopenic. Current practice is to
treat patients with prophylactic platelet transfusions, which are
triggered when the platelet count falls below 10,000/uL. Dr. Wandt
and colleagues compared this standard practice to an experimental
strategy of therapeutic platelet transfusions, where patients
received a transfusion only when they experienced a clinically
relevant bleed (more than petechias or minimal mucosal bleeding).

This new strategy significantly reduced the number of platelet
transfusions that were administered ¡X from 152 in the prophylactic
group to 118 in the therapeutic group, a reduction of 27% (P
= .004). There were 14 instances in the prophylactic group where the
trigger was reached but a transfusion was not given; if these are
included, the reduction is even greater (33%), Dr. Wandt reported.

In addition, with the therapeutic strategy, 46% of patients did not
need a platelet transfusion, which is nearly double the 22% in the
prophylactic group, Dr. Wandt commented.

The reduction in platelet transfusions seen in the therapeutic group
of this study could translate into huge cost savings. Dr. Wandt
estimated that if this strategy was implemented only for patients
who receive autologous transplants, based on figures from official
registries of such patients in the United States and Europe, an
estimated 16,460 apheresis platelet units could be saved each year.
This translates to cost savings of £á8 million or $10 million to $11
million each year.

More Bleeding Episodes in Therapeutic Group

There were more instances of clinically relevant bleeding in the
therapeutic group than in the prophylactic group (37% vs 7%),
although this is to be expected with a strategy that has bleeding as
the trigger for transfusion, Dr. Wandt commented. "All of the
bleeding events were of minor to moderate severity (grade 2 or 3)
and were safely treated with transfusions," he said.

"It is clear that bleeding episodes are increased, but these are
triggers for transfusion, and if you follow this strategy, you have
to accept this," Dr. Wandt commented. However, there were no severe
or fatal bleeds, he added.

There was no difference between the 2 groups in hospitalization,
number of red-blood-cell units transfused, or leukocytopenia. In
contrast, the duration of thrombocytopenia (platelet count of ≤
20,000/uL) was significantly longer in the therapeutic-transfusion
group than in the prophylactic group (median of 5 days vs 3 days; P
= .004), as would be expected with this strategy, Dr. Wandt
commented.

"We conclude that our therapeutic platelet-transfusion strategy is
cost effective and safe in patients after autologous stem-cell
transplantation," Dr. Wandt told the meeting. Despite more minor
hemorrhages with the experimental strategy than with the traditional
prophylactic strategy, all bleeding events could be safely
controlled by consecutive platelet transfusion, and development of
major bleeding could be prevented, he added.

However, several clinicians in the audience took issue with the
conclusion that this strategy was safe, saying that the patient
numbers were too small to detect a difference in severe bleeding
between the 2 groups.

Dr. Wandt countered by emphasizing that no major life-threatening
bleeds were seen in this study, nor in a previous study that his
group conducted in 140 patients with autologous stem-cell
transplants (Bone Marrow Transplant. 2006;37;387-392). His group is
currently conducting a similar randomized trial in patients with
acute myeloid leukemia, so more data will be available soon.

But he did acknowledge that the patient numbers so far may be too
small to detect a difference in severe bleeds, and he pointed out
that such a difference may be extremely small. His group previously
calculated that to detect such a difference, a clinical trial would
need to have 2000 patients in each group.

Asked to comment on this therapeutic platelet-transfusion strategy,
current ASH president Kenneth Kaushansky, MD, professor of medicine
at the University of California, San Diego, said that this was
interesting but it was too early to change clinical practice. "We
need more data," he said.

Sherrill Slichter, MD, an expert on platelet transfusions from the
Puget Sound Blood Center, in Seattle, Washington, agreed that more
data are needed, particularly in different patient populations. The
group for which there are the most data is autologous transplants
and, in her experience, this subgroup has a lower incidence of
bleeding than other groups. She noted that in the PLADO study that
she presented at the meeting, already reported by Medscape Oncology,
patients who received autologous transplants had a 54% rate of
bleeding, compared with 68% in patients who received chemotherapy,
and 72% in patients who received an allogeneic transplant. She said
it will be interesting to see results from the ongoing study in
acute myeloid leukemia patients, which Dr. Wandt hopes to present at
the ASH meeting next year.