UK consensus statement on the use of plerixafor to facilitate autologous peripheral blood stem cell collection to support high-dose chemoradiotherapy for patients with malignancy

Plerixafor is a CXC chemokine receptor (CXCR4) antagonist that mobilizes stem cells in the peripheral blood. It is indicated (in combination with granulocyte-colony stimulating factor [G-CSF]) to enhance the harvest of adequate quantities of cluster differentiation (CD) 34+ cells for autologous transplantation in patients with lymphoma or multiple myeloma whose cells mobilize poorly. Strategies for use include delayed re-mobilization after a failed mobilization attempt with G-CSF, and rescue or pre-emptive mobilization in patients in whom mobilization with G-CSF is likely to fail. Pre-emptive use has the advantage that it avoids the need to re-schedule the transplant procedure, with its attendant inconvenience, quality-of-life issues for the patient and cost of additional admissions to the transplant unit. UK experience from 2 major centers suggests that pre-emptive plerixafor is associated with an incremental drug cost of less than £2000 when averaged over all patients undergoing peripheral blood stem cell (PBSC) transplant. A CD34+ cell count of <15 µl^-1 at the time of recovery after chemomobilization or after four days of G-CSF treatment, or an apheresis yield of <1 × 10⁶ CD34+ cells/kg on the first day of apheresis, could be used to predict the need for pre-emptive plerixafor.

The role of extracorporeal photopheresis in the management of cutaneous T-cell lymphoma, graft-versus-host disease and organ transplant rejection: a consensus statement update from the UK Photopheresis Society

Extracorporeal photopheresis (ECP) has been used for over 35 years in the treatment of erythrodermic cutaneous T‐cell lymphoma (CTCL) and over 20 years for chronic and acute graft‐versus‐host disease (GvHD) and solid organ transplant rejection. ECP for CTCL and GvHD is available at specialised centres across the UK. The lack of prospective randomised trials in ECP led to the development of UK Consensus Statements for patient selection, treatment schedules, monitoring protocols and patient assessment criteria for ECP. The recent literature has been reviewed and considered when writing this update. Most notably, the national transition from the UVAR XTS^® machine to the new CELLEX machine for ECP with dual access and a shorter treatment time has led to relevant changes in these schedules. This consensus statement updates the previous statement from 2007 on the treatment of CTCL and GvHD with ECP using evidence based medicine and best medical practise and includes guidelines for both children and adults.

European data on stem cell mobilization with plerixafor in patients with nonhematologic diseases: an analysis of the European consortium of stem cell mobilization

BACKGROUND

Plerixafor with granulocyte-colony-stimulating factor (G-CSF) has been shown to enhance stem cell mobilization in patients with multiple myeloma and lymphoma with previous mobilization failure. In this European named patient program we report the experience in insufficiently mobilizing patients diagnosed with nonhematologic diseases.

STUDY DESIGN AND METHODS

Thirty-three patients with germ cell tumor (n=11), Ewing sarcoma (n=6), Wiscott-Aldrich disease (n=5), neuroblastoma (n=4), and other nonhematologic diseases (n=7) were included in the study. Plerixafor was limited to patients with previous or current stem cell mobilization failure and given after 4 days of G-CSF (n=21) or after chemotherapy and G-CSF (n=12) in patients who mobilized poorly.

RESULTS

Overall, 28 (85%) patients succeeded in collecting at least 2×10(6)/kg body weight (b.w.) CD34+ cells (median, 5.0×10(6)/kg b.w. CD34+ cells; range, 2.0×10(6)-29.5×10(6)/kg b.w. CD34+ cells), and five (15%) patients collected a median of 1.5×10(6)/kg b.w. CD34+ cells (range, 0.9×10(6)-1.8×10(6)/kg b.w. CD34+ cells). Nineteen patients proceeded to transplantation. The median dose of CD34+ cells infused was 3.3×10(6)/kg b.w. (range, 2.3×10(6)-6.7×10(6)/kg b.w. CD34+ cells). The median numbers of days to neutrophil and platelet engraftment were 11 (range, 9-12) and 15 (range, 10-25) days, respectively.

CONCLUSION

These data emphasize the role of plerixafor in combination with G-CSF or chemotherapy and G-CSF as an effective mobilization regimen with the potential of successful stem cell collection. Accordingly, plerixafor seems to be safe and effective in patients with nonhematologic diseases. Larger prospective studies are warranted to further assess its use in these patients.

European data on stem cell mobilization with plerixafor in non-Hodgkin's lymphoma, Hodgkin's lymphoma and multiple myeloma patients. A subgroup analysis of the European Consortium of stem cell mobilization

The effectiveness of the novel hematopoietic stem cell mobilizing agent plerixafor was evaluated in nationwide compassionate use programs in 13 European countries. A total of 580 poor mobilizers with non-Hodgkin's lymphoma (NHL), Hodgkin's lymphoma (HL) and multiple myeloma (MM) were enrolled. All patients received plerixafor plus granulocyte CSF with or without chemotherapy. Overall, the collection yield was significantly higher in MM patients (>2.0 × 10(6) CD34+ cells/kg: 81.6%; >5.0 × 10(6) CD34+ cells/kg: 32.0%) than in NHL patients (>2.0 × 10(6) CD34+ cells/kg: 64.8%; >5.0 × 10(6) CD34+ cells/kg: 12.6%; P<0.0001) and also significantly higher in HL patients (>2.0 × 10(6) CD34+ cells/kg: 81.5%; >5.0 × 10(6) CD34+ cells/kg: 22.2%) than in NHL patients (P=0.013). In a subgroup analysis, there were no significant differences in mobilization success comparing patients with diffuse large B-cell lymphoma, follicular lymphoma and mantle cell lymphoma. Our data emphasize the role of plerixafor in poor mobilizers, but further strategies to improve the apheresis yield especially in patients with NHL are required.

Plerixafor for PBSC mobilisation in myeloma patients with advanced renal failure: safety and efficacy data in a series of 21 patients from Europe and the USA

We describe 20 patients with myeloma and 1 with primary amyloidosis from 15 centres, all with advanced renal failure, most of whom had PBSC mobilised using plerixafor following previous failed mobilisation by conventional means (plerixafor used up-front for 4 patients). For 15 patients, the plerixafor dose was reduced to 0.16 mg/kg/day, with a subsequent dose increase in one case to 0.24 mg/kg/day. The remaining six patients received a standard plerixafor dosage at 0.24 mg/kg/day. Scheduling of plerixafor and apheresis around dialysis was generally straightforward. Following plerixafor administration, all patients underwent apheresis. A median CD34+ cell dose of 4.6 × 10(6) per kg was achieved after 1 (n=7), 2 (n=10), 3 (n=3) or 4 (n=1) aphereses. Only one patient failed to achieve a sufficient cell dose for transplant: she subsequently underwent delayed re-mobilisation using G-CSF with plerixafor 0.24 mg/kg/day, resulting in a CD34+ cell dose of 2.12 × 10(6)/kg. Sixteen patients experienced no plerixafor toxicities; five had mild-to-moderate gastrointestinal symptoms that did not prevent apheresis. Fifteen patients have progressed to autologous transplant, of whom 12 remain alive without disease progression. Two patients recovered endogenous renal function post autograft, and a third underwent successful renal transplantation. Plerixafor is highly effective in mobilising PBSC in this difficult patient group.

Infection frequently triggers thrombotic microangiopathy in patients with preexisting risk factors: a single-institution experience

Thrombotic microangiopathies are rare conditions characterized by microangiopathic hemolytic anemia, microthrombi, and multiorgan insult. The disorders, which include hemolytic uremic syndrome and thrombotic thrombocytopenic purpura, are often acute and life threatening. We report a retrospective analysis of 65 patients presenting to our institution from 1997 to 2008 with all forms of thrombotic microangiopathy. Therapeutic plasma exchange was a requirement for analysis and 65 patients were referred to our institution; 66% of patients were female and median age at presentation was 52 years. Bacterial infection was the most commonly identified etiologic factor and in the multivariate model was the only significant variable associated with survival outcome (odds ratio 5.1, 95% confidence interval, 1.2-21.7). As infection can be considered a common trigger event for thrombotic microangiopathy, patients with hepatobiliary sepsis may benefit from elective cholecystectomy. We conclude that bacterial infection frequently triggers TTP and other thrombotic microangiopathies in patients with preexisting risk factors and propose a model for the development of these syndromes.

Ideal body weight correlates better with engraftment after PBSC autograft than actual body weight, but is under-estimated in myeloma patients possibly due to disease-related height loss

Stem cell dose is important in determining rate of engraftment following autograft. We show closer correlation with haematopoietic reconstitution when the CD34+ cell dose is calculated using ideal (IBW) rather than actual (ABW) body weight in 218 patients receiving peripheral blood stem cell (PBSC) autograft for haematological malignancy. ABW was 21% greater than IBW thus the median CD34+ dose of 5.0 x 10(6)/kg (ABW) rose to 6.1 x 10(6)/kg when calculated by IBW. Neutrophils reached 0.5 x 10(9)/l in 11 days (range 8-21), while platelets reached 20 x 10(9)/l unsupported in 12 days (range 7-38). For both neutrophil and platelet engraftment, a greater inverse correlation was seen when IBW was used to calculate stem cell dose (r2=0.082 vs r2=0.104 for neutrophils and r2=0.085 vs r2=0.135 for platelets). Those non-myeloma patients who failed to achieve a CD34+ dose of 4 x 10(6) cells/kg by ABW but did so by IBW achieved neutrophil and platelet engraftment not significantly different from those who achieved that stem cell dose by both methods. This was not confirmed in patients treated for myeloma, possibly owing to inaccurate IBW in patients with skeletal height loss. We confirm that calculation of CD34+ cell dose by IBW safely predicts engraftment for patients with haematological malignancies other than myeloma undergoing PBSC autograft.

Dose escalation therapy in previously untreated patients with multiple myeloma following Z-Dex induction treatment

A phase I-II study of high-dose (HD) alkylating agents in newly diagnosed patients with multiple myeloma after maximum response to Z-Dex (idarubicin, dexamethasone) therapy and DHAP (cisplatin, HD cytosine arabinoside, dexamethasone), stem cell mobilization is reported. Twenty-six patients, median age 56 years (range 42-66), completed Z-Dex chemotherapy and peripheral blood stem cells (PBSC) were mobilized with DHAP. Patients then preceded to cyclophosphamide (HD Cy: 6 g/m(2)) with granulocyte colony-stimulating factor followed by busulphan-melphalan-conditioned PBSC autograft. Interferon alpha was introduced at 3 months post transplant as maintenance therapy. Six patients failed to complete the full protocol. Median time from diagnosis to transplantation was 8 months (range 6-12). Mean CD34+ cell dose collected was 15.8 x 10(6)/kg (CI 11.8, 19.8). Median time from DHAP to HD-Cy was 6 weeks (range 4-12) and from HD-Cy to transplant was 8 weeks (range 6-12). The median follow-up was 36 months (range 6-63). On an intent-to-treat basis, the response rates were three complete response (CR, 12%), 21 partial response (PR, 80%) and two stable disease (SD, 8%) post Z-Dex, five CR (19%) and 21 PR (81%) post HD-Cy, and 14 CR (54%) and 12 PR (46%) post transplant. The treatment-related mortality (TRM) was 4% (1 patient). Median overall survival (OS) and progression-free survival (PFS) have not been reached; estimated values were 60 and 48 months respectively. The 3-year OS and PFS were 72% and 62%. Actuarial 5-year OS and event-free survival were 49% and 32%. DHAP produces effective PBSC mobilization and sequential HD therapy, including autologous PBSCT, in patients who received Z-Dex; this offers significant durable disease response rates with acceptable TRM.