Plerixafor given before the third leukapheresis to rescue an unsuccessful stem cell mobilization with CY and G-CSF

Rescue stem cell mobilization with plerixafor economizes leukapheresis in patients with multiple myeloma

While extensive data demonstrated that plerixafor improves stem cell harvest in difficult-to-mobilize patients, economic concerns limit a broader application. We retrospectively assessed the effect of an early plerixafor rescue regimen for mobilization in patients with multiple myeloma. Patients were intended for high-dose chemotherapy followed by autologous peripheral blood stem cell transplantation (ABSCT) and therefore received cyclophosphamide-based mobilization chemotherapy and consecutive stimulation with granulocyte colony-stimulating factor (G-CSF). Fifteen patients with poor stem cell harvest in the first leukapheresis session received plerixafor. Data were compared with a matched historic control group of 45 patients who also had a poor stem cell yield in the first apheresis session, but continued mobilization with G-CSF alone. Patients in the plerixafor group collected significantly more CD34+ cells in total (median 4.9 vs. 3.7 [range 1.6-14.1 vs. 1.1-8.0] × 10(6) CD34+ cells /kg bw; P < 0.05), and also more CD34+ cells per leukapheresis procedure (P < 0.001). Consequently, they required a significantly lower number of leukapheresis procedures to achieve the collection goal (median 2.0 vs. 4.0 [range 2-3 vs. 2-9] procedures; P < 0.001). The efficiency of the collected stem cells in terms of hematologic engraftment after ABSCT was found to be equal in both groups. These data demonstrate that rescue mobilization with plerixafor triggered by a low stem cell yield in the first leukapheresis session is effective. Although the actual economic benefit may vary depending on the local leukapheresis costs, the median saving of two leukapheresis procedures offsets most of the expenses for the substance in this setting. An exemplary cost calculation is provided to illustrate this effect.

Optimizing autologous stem cell mobilization strategies to improve patient outcomes: consensus guidelines and recommendations

Autologous hematopoietic stem cell transplantation (aHSCT) is a well-established treatment for malignancies such as multiple myeloma (MM) and lymphomas. Various changes in the field over the past decade, including the frequent use of tandem aHSCT in MM, the advent of novel therapies for the treatment of MM and lymphoma, and the addition of new stem cell mobilization techniques, have led to the need to reassess current stem cell mobilization strategies. Mobilization failures with traditional strategies are common and result in delays in treatment and increased cost and resource utilization. Recently, plerixafor-containing strategies have been shown to significantly reduce mobilization failure rates, but the ideal method to maximize stem cell yields and minimize costs associated with collection has not yet been determined. A panel of experts convened to discuss the currently available data on autologous hematopoietic stem cell mobilization and transplantation and to devise guidelines to optimize mobilization strategies. Herein is a summary of their discussion and consensus.

Priming of hematopoietic progenitor cells by plerixafor and filgrastim in children with previous failure of mobilization with chemotherapy and/or cytokine treatment

Plerixafor has been recently approved by the European Medicines Agency for adult patients who have failed other mobilization strategies. Experience in children, however, is extremely limited. We describe the experience of the use of this drug in 8 children under a compassionate-use program in 3 Italian and 2 Spanish centers. Plerixafor was generally well tolerated; only 2 of 8 children reported adverse effects, and these were mild in intensity. Peripheral blood progenitor cell priming was improved with plerixafor in 6 of 8 patients. In the remaining 2 patients, the target CD34+ cell count was below the target of 2 × 10(6) cells/kg, although in these patients cell counts before collection were good enough for leukapheresis. Plerixafor, therefore seems to be safe and effective for peripheral blood progenitor cell mobilization in children. Adverse events were comparable with those described with filgrastim alone.

Hematopoietic recovery kinetics predicts for poor CD34+ cell mobilization after cyclophosphamide chemotherapy in multiple myeloma

Autologous stem cell transplantation is an important part of therapy in patients with multiple myeloma. Some patients fail to collect the desired number of stem cells while others require multiple apheresis to reach the desired apheresis target. The aim of this study was to determine the predictive factors and if the hematopoietic kinetics of recovery were predictive for outcome of stem cell mobilization in cyclophosphamide + growth factor (CY-GF) mobilized patients. Three hundred and ninety six consecutive CY-GF mobilization attempts between January 2000 and December 2009 at Mayo Clinic, Rochester, MN were analyzed. Patients were divided into three groups: optimal (>5 × 10(6) CD34/kg), suboptimal (2-5 × 10(6) CD34/kg) and poor (<2 × 10(6) /kg CD34+ cells) mobilization groups. About 86% of patients had optimal stem cell collection, whereas 8% had suboptimal collection and 6% had poor (or failed) collections. Age, Hb, WBC, and platelet levels had an impact on mobilization results. Time to peripheral blood (PB) CD34+cells >10/μL predicted for efficiency of collection and the interval between recovery of WBC>1 post-CY to PB CD34+ cells>10 was shorter in the optimal collection groups. These findings suggest that for patients with a PB CD34+ cell count below 10/μL on Day 13 following CY or 1 day after the WBC>1 × 10(9) /L, addition of plerixafor may be helpful to salvage the mobilization attempt.

Successful mobilization of peripheral blood stem cells in children with cancer using plerixafor (Mozobil) and granulocyte-colony stimulating factor

This paper describes the successful mobilization of peripheral blood stem cells for autologous transplantation in three children with malignant diseases by using plerixafor (Mozobil; Genzyme Corporation, Cambridge, MA) and granulocyte-colony stimulating factor (G-CSF) after failed previous mobilizations. A median sixfold increase in the number of circulating CD34+ cells after plerixafor treatment as compared with the baseline level was observed. An optimal CD34+ cell count for transplantation with one or two leukapheresis sessions was achieved. Mobilization using plerixafor was found to be safe with no adverse events. Therefore, the combination of G-CSF and plerixafor in children results in effective increases in peripheral CD34+ cell counts and reduces the risk of mobilization failure.