MGTA-145 + Plerixafor in the Mobilization of Hematopoietic Stem Cells for Autologous Transplantation in Multiple Myeloma

The study Primary Objective is to assess the efficacy of hematopoietic stem cells (HSC) mobilization with MGTA-145 in combination with plerixafor in patients with multiple myeloma (MM) in preparation for autologous stem cell transplantation (ASCT). The primary outcome was assessed as the number of participants for whom 2.0 x 10e6 CD34+ HSC cells/kg could be collected in 1 or 2 apheresis harvests, after mobilization with MGTA-145 and Plerixafor. The outcome is reported as the number of participants who achieved this level of HSC cells, a number without dispersion.

The study Primary Objective is to assess the efficacy of hematopoietic stem cells (HSC) mobilization with MGTA-145 in combination with plerixafor in patients with multiple myeloma (MM) in preparation for autologous stem cell transplantation (ASCT). Other secondary outcomes were assessed as the number of participants for whom 2.0 or 4.0 x 10e6 CD34+ HSC cells/kg could be collected in the Day 1 apheresis harvest only, and for whom the total yield ≥ 4.0 or ≥ 6.0 x 106 CD34+ cells/kg. The outcome is reported as the number of participants who achieved these levels of HSC cells, a number without dispersion.

Neutrophil engraftment after hematopoietic stem cells (HSC) transplant (infusion) is an important measure of the medical benefit of the mobilization and hematopoietic stem cells (HSC) infusion procedure. Time to neutrophil engraftment is defined as the number of days from the day of stem cell infusion to the 1st day of 3 consecutive days that absolute neutrophil count (ANC) is ≥ 0.5 x 10e9/L. Only the participants that proceeded to the HSC infusion are included in this outcome, with the outcome is expressed as the median number of days with full range.

Maintenance of successful engraftment after initial engraftment is an important assessment of the value of the mobilization and hematopoietic stem cells (HSC) infusion procedure. For participants with successful neutrophil engraftment [absolute neutrophil count (ANC) ≥ 0.5 x 10e9/L], the outcome is reported as the number of participants that had maintained successful graft status [absolute neutrophil count (ANC) ≥ 0.5 x 10e9/L] at 30 days and 100 days after the infusion. The outcome is a number without dispersion.

Platelet engraftment after hematopoietic stem cells (HSC) transplant (infusion) is an important measure of the medical benefit of the mobilization and hematopoietic stem cells (HSC) infusion procedure. Time to platelet engraftment ≥ 20 x 10e9/L is defined as the 1st day of 2 consecutive days that platelet count is ≥ 20 x 10e9/L, without transfusion in the prior 7 days. Only the participants that proceeded to the HSC infusion are included in this outcome, with the outcome is expressed as the median number of days with full range.

Platelet engraftment after hematopoietic stem cells (HSC) transplant (infusion) is an important measure of the medical benefit of the mobilization and hematopoietic stem cells (HSC) infusion procedure. Time to platelet engraftment ≥ 50 x 10e9/L s defined as the 1st day that platelet count is ≥ 50 x 10e9/L, without transfusion in the prior 48 hours. Only the participants that proceeded to the HSC infusion are included in this outcome, with the outcome is expressed as the median number of days, with full range.

Infusion-related toxicities are adverse events considered at least possibly-related to the study treatments MGTA-145, assessed from Baseline to 7 days after mobilization. The outcome is reported as a listing of the preferred terms for the "at least possibly-related" adverse events, with outcome being the number of adverse events of that preferred term. The outcome is a listing of numbers without dispersion.

Progression-free survival (PFS) is an important assessment of the value of the mobilization and hematopoietic stem cells (HSC) infusion procedure. For participants that received the HSC infusion, the outcome is reported as the number of participants who remained alive and were without tumor progression, at 100 days after the infusion. The outcome is a number without dispersion.

Transplant-related mortality is an important assessment of the value of the mobilization and hematopoietic stem cells (HSC) infusion procedure. For participants that received the HSC infusion, the outcome is reported as the number of participants who had expired for any reason considered at least possibly related to the transplant / infusion procedure, within 100 days of the infusion. The outcome is a number without dispersion.

For participants that received the HSC infusion, the outcome is reported as the number of participants who had expired for any reason except disease relapse/progression, within 100 days of the infusion. The outcome is a number without dispersion.

Only patients proceeding with upfront transplant will be assessed. Overall survival is defined as duration from start of the ASCT to death (regardless of cause of death). This will be assessed from start of transplant and OS rates will be reported at day100 following transplant in patients undergoing upfront transplant.

Overall survival (OS) is an important assessment of the value of the mobilization and hematopoietic stem cells (HSC) infusion procedure. For participants that received the HSC infusion, the outcome is reported as the number of participants who remained alive at 100 days after the infusion. The outcome is a number without dispersion.