Patients Receiving Palifermin in Conjunction with Melphalan 200 Required Fewer Platelet Transfusions: Analysis of a Retrospective Cohort Study.

Background: Mucosal injury and concomitant associated side effects represents a major toxicity of autologous transplant for myeloma. The use of Palifermin has been demonstrated to reduce mucositis severity scores and duration in randomized trials. We sought to evaluate the effect of palifermin on overall platelet transfusion requirements as an indirect measure of reduced GI toxicity. Since palifermin has been shown to decrease mucosal damage caused by conditioning regimens for PBSCT, it was theorized that palifermin’s protective effects might lead to a reduction in the platelet transfusion requirements for these patients.

Methods: Thirty six consecutive myeloma PBSCT patients conditioned with melphalan 200 mg/m² plus palifermin (dosed per manufacturers recommendations) were retrospectively evaluated for platelet transfusion requirements following autologous transplant. As a historical control, data were retrospectively collected on thirty eight consecutive myeloma PBSCT patients conditioned with the same regimen prior to the routine use of palifermin. Platelet support consists of transfusion of leukoreduced irradiated single donor pheresis products. Platelet transfusions were dictated by standard clinical practice on the transplant service either for a routine platelet count <10K or 20k when patients had evidence for bleeding. Identical platelet transfusion criteria were used in the control and palifermin groups. The number of platelet transfusions required from the time of transplant until platelet recovery was analyzed for each patient. Patients who did not have adequate platelet recovery (Platelets <100,000) at the initiation of transplant conditioning were excluded from analysis in both groups.

Results: The palifermin and control patients were of similar age and renal function. Baseline median platelet count was higher in the palifermin group (260 vs 213.5; p=.01), but both groups had mean platelet counts well above the normal range. Patients in the palifermin group required an average of 1.11 platelet transfusions compared with 2.42 transfusions for the control group (p=.055). In the palifermin group, 17 (46%) of the patients required no platelet transfusions compared to only 8 (21%) in the control group (p=.017). When analyzing only the patients who had normal platelet count (> 150,000) prior to start of the conditioning regimen, the palifermin patients (33) required an average of 1.1 transfusions compared to 1.7 transfusions in the control patients (33). The numbers of patients requiring only 1 transfusion were 11 (31%) in the palifermin group and 13 (34%) in the control group. The time to platelet engraftment was similar in both the 2 groups (14.5 days in the palifermin group and 15 days in the control group).

Conclusion: The use of palifermin is associated with reduced platelet transfusion requirements among a group of patients who received melphalan 200 mg/m² conditioning and autologous transplant for myeloma. Further cost analysis and quality of life analysis are needed to further justify this approach for all patients.