Influence of Clonal Plasma Cell Contamination of Peripheral Blood Stem Cell Autografts on Progression and Survival in Multiple Myeloma Patients After Autologous Peripheral Blood Stem Cell Transplantation in Long-term Observation.

BACKGROUND: High-dose chemotherapy followed by autologous peripheral blood stem cell transplantation (auto-PBSCT) remains the mainstay of treatment of eligible patients diagnosed multiple myeloma. The role of clonal plasma cell (CPC) contamination was found as a reason for relapse, but results in terms of survival, progression, and purging were ambiguous. Therefore, the aim of the study was to explore the influence of CPC contamination in the autograft on survival and progression after auto-PBSCT. STUDY DESIGN: The study included 59 patients diagnosed and treated for multiple myeloma in 1998-2004. Cells with coexpression of CD38+++CD138++CD56+ and lacking the expression of CD45, CD19, CD10, CD20, and CD23 were considered CPC in flow cytometry. RESULTS: The risk of death and progression after auto-PBSCT increased significantly by 10% (P < .021) and 8% (P < .034) per 1 × 106/kg of the CPC number, respectively. For CPC number above 2.96 × 106/kg overall survival achieved clinical significance. Two years after auto-PBSCT, the risk of death was independent of CPC number among the patients who survived (P = .70). Analogous conclusions concerned results of progression-free survival at 1 year after auto-PBSCT. CONCLUSIONS: High clonal plasma cell contamination (>2.96 ×1 06/kg; 90th percentile of CPC number) is associated with the worst progression-free survival and overall survival. Therefore purging in vitro might be considered for the patients with the highest CPC contamination. Negative consequences of CPC contamination on the risk of death are observed for only 2 years after auto-PBSCT. Thereafter only those patients who had lower CPC contamination survived.

Azacitidine for Relapse After Allogeneic Stem Cell Transplantation-Single-Center Study.

BACKGROUND: Relapse is the leading cause of treatment failure for myeloid malignancies treated with allogeneic hematopoietic stem cell transplantation. Treatment options are very limited and use of azacitidine is one of the available options. METHODS: This was a retrospective, single-institution study. Of 28 evaluated patients, 18 were males, and the median age was 60 years (range, 15-78). There were 15 patients with acute myeloid leukemia, 8 with myelodysplastic syndrome, 4 with chronic myelomonocytic leukemia, and 1 with primary myelofibrosis. Ten patients received azacitidine for overt relapse, 14 received it as a preemptive therapy, and 4 others received it as maintenance treatment after allo-hematopoietic cell transplant (HSCT). Eleven patients received a donor lymphocyte infusion (DLI). RESULTS: The patients received median 5 (1-9) cycles of azacitidine in preemptive and maintenance therapy and median 2.5 (1-9) cycles in patients with relapse. Thirty-nine percent of patients received DLIs. Median overall survival was 6.1 months (95% CI, 0.7-13) for relapse therapy vs 21.2 months (95% CI, 8.4-inf) for preemptive therapy. Among patients treated for relapse, 30% achieved temporary disease control and underwent the second allo-HSCT. A complete, cytogenetic remission was achieved in 50% of patients and stable minimal residual disease in 14% of patients in a group with preemptive therapy. Toxicity was considerable; neutropenia (71%), anemia (14%), thrombocytopenia (36%), and serious infections (36%) were observed in the preemptive setting. CONCLUSIONS: These data support the notion that azacitidine is best used as a preemptive therapy against relapse for patients after allo-HSCT performed for myeloid malignancy. Applying azacitidine as therapy for ongoing relapse after allo-HSCT may lead to stable disease and allow for better performance of the second allo-HSCT.

Azacitidine Use After Allogeneic Stem Cell Transplantation-Results From the Polish Adult Leukemia Group.

BACKGROUND: Relapse of primary hematologic disease constitutes an important reason for failure of allogeneic hematopoietic stem cell transplantation (alloHSCT). There are very few treatment modalities for this indications. Therefore, there is a need for novel effective therapies and even more for the prevention of relapse. There are scarce data that azacitidine can be used for these purposes. METHODS: At the Polish Adult Leukemia Group, we retrospectively analyzed the results of azacitidine treatment after alloHSCT. Relapsing patients, patients with minimal residual disease/mixed chimerism, and patients in complete remission with high risk of relapse were analyzed separately. There were 17 patients, 6 with myelodysplastic syndrome, 11 with acute myeloid leukemia, 8 male, and overall median age of 56 years (range, 15-78); 7 patients received donor lymphocyte infusion (DLI). RESULTS: Patients treated because of relapse received a median of 3 (range, 1-6) cycles of azacitidine, patients receiving preemptive treatment received a median of 4 cycles (range, 2-6), and those on maintenance received a median of 5 cycles (range, 3-5). Toxicity was considerable, especially in relapse-neutropenia (67%), anemia (67%), thrombocytopenia (100%), serious infections (78%)-and preemptive settings. Median overall survival of patients treated for relapse reached 6.8 months (95% confidence interval [CI], 0.7-∞), with better survival observed in patients with temporary disease control (7.7 vs 4.7 mo) and without previous exposure to azacitidine (7.7 vs 3.4 mo). One-year overall survival reached 75% (95% CI, 13%-96%) for preemptive and 50% (95% CI, 0%-91%) for maintenance treatment. DLI did not aggravate graft-versus-host disease. CONCLUSIONS: Effectiveness of azacitidine in relapsing patients is disappointing. Azacitidine seems to be promising in preemptive and maintenance settings. Toxicity is considerable. Further research is needed.