Stem Cell Harvesting after Bortezomib-Based Reinduction for Myeloma Relapsing after Autologous Transplantation: Results from the British Society of Blood and Marrow Transplantation/United Kingdom Myeloma Forum Myeloma X (Intensive) Trial

Stem Cell Mobilization Performed with Different Doses of Cytarabine in Plasma Cell Myeloma Patients Relapsing after Previous Autologous Hematopoietic Cell Transplantation-A Multicenter Report by the Polish Myeloma Study Group

Salvage autologous hematopoietic cell transplantation (auto-HCT) may be used to treat relapse of plasma cell myeloma occurring after previous auto-HCT. When an insufficient number of hematopoietic stem cells have been stored from the initial harvest, remobilization is necessary. Here, we aimed to analyze the efficacy and safety of different doses of cytarabine (total 800 vs. 1600 vs. 2400 mg/m2) for remobilization. Sixty-five patients, 55% male, with a median age at remobilization 63 years, were included. Remobilization was performed with cytarabine_800 in 7, cytarabine_1600 in 36, and cytarabine_2400 in 22 patients. Plerixafor rescue was used in 25% of patients receiving cytarabine_1600 and 27% of those receiving cytarabine_2400. Patients administered cytarabine_800 were not rescued with plerixafor. Remobilization was successful in 80% of patients (57% cytarabine_800; 86% cytarabine_1600; 77% cytarabine_2400; p = 0.199). The yield of collected CD34+ cells did not differ between the different cytarabine doses (p = 0.495). Patients receiving cytarabine_2400 were at the highest risk of developing severe cytopenias, requiring blood product support, or having blood-stream infections. One patient died of septic shock after cytarabine_2400. In summary, remobilization with cytarabine is feasible in most patients. All doses of cytarabine allow for successful remobilization. Cytarabine_2400 is associated with higher toxicity; therefore, lower doses (800 or 1600 mg/m2) seem to be preferable.

Autologous hematopoietic cell transplantation for relapsed multiple myeloma performed with cells procured after previous transplantation-study on behalf of CMWP of the EBMT

Autologous hematopoietic cell transplantation (auto-HCT) may be performed in multiple myeloma (MM) patients relapsing after a previous auto-HCT. For those without an adequate dose of stored stem cells, remobilization is necessary. This retrospective study included patients who, following disease relapse after the first auto-HCT(s), underwent stem cell remobilization and auto-HCT performed using these cells. There were 305 patients, 68% male, median age at salvage auto-HCT was 59 years. The median time to relapse after the first-line penultimate auto-HCT(s) was 30.6 months, the median follow-up after salvage auto-HCT 31 months. The 2- and 4-year non-relapse mortality (NRM) after the salvage auto-HCT was 5 and 9%, the relapse incidence 56 and 76%, respectively. Overall survival (OS) after 2 and 4 years was 76 and 52%, progression-free survival (PFS) 39 and 15%. In multivariable analysis an increasing interval between the penultimate auto-HCT and relapse was associated with better OS and PFS, later calendar year of salvage auto-HCT with better OS. In conclusion, salvage auto-HCT performed with cells remobilized after a previous auto-HCT was associated with acceptable NRM. The leading cause of failure was disease progression of MM, which correlated with a shorter interval from the penultimate auto-HCT to the first relapse.

Salvage autologous hematopoietic stem cell transplantation for multiple myeloma performed with stem cells procured after previous high dose therapy - a multicenter report by the Polish Myeloma Study Group

Salvage autologous hematopoietic stem cell transplantation (auto-HSCT) constitutes a therapeutic option for a group of well-selected patients with relapsed multiple myeloma (MM). However, if an insufficient number of stem cells were harvested and stored before the first auto-HSCT, stem cells need to be remobilized. Patients diagnosed with MM who following relapse after auto-HSCT, had remobilization and afterward, auto-HSCT with remobilized cells were included in this retrospective analysis. Thirty-three patients, 61% males, the median age 61 years, were included. With a median follow-up of 1.8 years, 2-year progression-free survival was 56.2%, non-relapse mortality 4.8%. The 2-year cumulative incidence of t-MDS was 4.9%. Factors important for the outcome were: the quality of response, previous radiotherapy, the time between the first and salvage auto-HSCT. To conclude, salvage auto-HSCT performed with cells procured after the previous auto-HSCT can be efficacious in relapsed MM, especially if a sufficiently long response had been obtained to the first auto-HSCT(s).

Stem cell mobilization in multiple myeloma patients relapsing after previous autologous hematopoietic stem cell transplantation: A multicenter report by the Polish Myeloma Study Group

BACKGROUND

Salvage autologous hematopoietic stem cell transplantation (autoHSCT) may be used to treat relapse of multiple myeloma occurring after previous autoHSCT. When insufficient number of hematopoietic stem cells was stored from the initial harvest, remobilization of stem cells is necessary.

PURPOSE

The analysis of stem cell remobilization after previous autoHSCT.

PATIENTS AND METHODS

Fifty-eight patients, 60% males, median 59 years, were included. Median time interval between autoHSCT and remobilization was 42 months. The first remobilization was performed mostly after chemotherapy: cyclophosphamide (33%), cytarabine (43%), and etoposide (19%).

RESULTS

The first remobilization was successful in 67% patients. About 19% patients required plerixafor rescue, among whom it allowed for successful harvesting in 14%. Use of cyclophosphamide, cytarabine, and etoposide allowed for successful remobilization in 53%, 84%, and 55% patients, respectively. Patients treated with cytarabine had the highest yield of CD34+ cells (median 7.5 × 10⁶ /kg vs 5.8 and 2.4 for etoposide and cyclophosphamide, P = .001). Higher percentage of patients was able to collect ≥2 × 10⁶ CD34+ cells/kg during one leukapheresis after cytarabine (76% vs 21% for cyclophosphamide vs 36% for etoposide, P = .001). Cytarabine use was associated with lower risk of remobilization failure OR = 0.217, P = .02. Toxicity comprised mostly hematological toxicity (thrombocytopenia and neutropenia). One patient succumbed to septic shock.

CONCLUSION

Remobilization after previous autoHSCT is feasible only in a proportion of patients. Cytarabine is associated with the highest rate of successful mobilization and the highest yield of mobilized CD34+ cells. The toxicity requires careful surveillance of these patients.

How I manage frontline transplant-eligible multiple myeloma in Italy

The treatment of transplant-eligible multiple myeloma patients in Italy consists in an induction phase based on bortezomib plus thalidomide plus dexamethasone (VTd), followed by a single or tandem autologous stem cell transplantation (ASCT), followed by lenalidomide maintenance. This approach offers an overall response rate of 93% and a CR rate of 58% with acceptable toxicity. Lenalidomide maintenance adds a significant increase in disease control, with a progression free survival after ASCT of 53 months, and an overall survival of 86 months. Second primary malignancies represent the most concerning toxicity of lenalidomide maintenance with a 6.9% incidence. However, the benefit in terms of increased myeloma control largely outweigh this complication. The incorporation of daratumumab in this treatment schema will further improve these clinical results.

Cyclophosphamide-based stem cell mobilization in relapsed multiple myeloma patients: A subgroup analysis from the phase III trial ReLApsE

OBJECTIVE

Analysis of the efficiency and toxicity of cyclophosphamide-based stem cell mobilization in patients with relapsed multiple myeloma (RMM).

METHODS

Peripheral blood stem cells (PBSCs) were mobilized with high dose cyclophosphamide (2 g/m² daily on days 1 and 2) and G-CSF plus pre-emptive/rescue plerixafor in RMM patients (first to third relapse) treated within the ReLApsE trial of the German-Speaking Myeloma Multicenter Group (GMMG).

RESULTS

Mobilization was initiated with high-dose cyclophosphamide (HD-CY) and G-CSF in 30 patients. Fifteen patients received additional pre-emptive/rescue administration of plerixafor. Stem cell collection was successful (≥2×10⁶ CD34+ cells per kg bw) in 77% (23/30 patients). Patients with prior high-dose melphalan collected a significantly lower median total number of PBSCs than patients without prior high-dose melphalan (3.3×10⁶ vs 17×10⁶ CD34+ cells/kg bw). Toxicity of HD-CY was frequent with 12 serious adverse events (SAE) in 37% of patients (11/30 patients). Infections accounted for the majority of SAE reports. In two patients, SAEs were lethal (septic shock).

CONCLUSIONS

These data proof feasibility of PBSC collection at relapse but emphasize the importance of collection and storage of additional PBSC transplants during first-line treatment when mobilization is more efficient and less toxic.