Plerixafor on-demand in association with low-dose cyclophosphamide and G-CSF in the mobilization of patients with multiple myeloma: High effectiveness, low toxicity, and affordable cost.

In CD34+ cells mobilization of patients with multiple myeloma (MM), the use of Cyclophosphamide (CTX) at a dose of 2 g/m2 has low efficacy although also lower toxicity. The suboptimal mobilizing effect of low-dose CTX, however, may be overcome by plerixafor (PLX) on demand. We conducted a prospective multicenter study in 138 patients with MM to evaluate CTX 2 g/m2 in association with granulocyte-colony stimulating factor (G-CSF) and on-demand PLX. We compared results with a historical group of MM patients (n = 138) mobilized using CTX at a dose of 4 g/m2. CD34+ cells greater than 2 × 106/kg in max three aphereses were harvested in 98.6% of patients in the on-demand PLX study group while in 84.0% in the historical group, (p = 0.0001). In the on-demand-PLX study group, a successful harvest greater than 5 × 106/kg in max three aphereses was observed in 85.5% of patients versus 62.3% of patients in the historical control group, (p=0.0001). In the on-demand-PLX study group, 4.3% (6/138) of patients had febrile complications. Salvage mobilization in the on-demand PLX study group was 1.4%. In conclusions, on-demand PLX + CTX 2 g/m2 + G-CSF 10 µg/kg has higher efficacy and lower toxicity compared with CTX 4 g/m2 + G-CSF. An analysis of costs is presented.

Cost-effectiveness of on-demand plerixafor added to chemotherapy and granulocyte-colony stimulating factor for peripheral blood stem cell mobilization in multiple myeloma.

We here report final results of a phase II/III prospective study that evaluated in Multiple Myeloma the use of on-demand plerixafor (PLX) added to mobilizing chemotherapy for patients showing predictive signs of mobilization failure. A total of 111 patients with MM were registered, all received cyclophosphamide 4 g/m2 and granulocyte colony-stimulating factor (G-CSF). Overall, a successful CD34+ cell mobilization was achieved in 97.2% (108/111) of patients. Minimum harvest (≥2.0 × 106 CD34+ cells/kg) was achieved in 97.2% (108/111) and optimal harvest success (≥4.0 × 106 CD34+ cells/kg) was achieved in 84.6% (94/111). Multivariate analysis showed that patients who received on-demand PLX treatment had significantly higher likelihoods of successfully achieving both the minimal (p = .006) and optimal harvest (p = .05) in respect to a historical control group mobilized without any PLX. The incremental cost-effectiveness ratio, for each 1% increase in probability of achieving a successful minimal harvest, was €40.6 per patient.

Plerixafor on-demand combined with chemotherapy and granulocyte colony-stimulating factor: significant improvement in peripheral blood stem cells mobilization and harvest with no increase in costs.

To date, no prospective study on Plerixafor 'on-demand' in combination with chemotherapy and granulocyte colony-stimulating factor (G-CSF) has been reported. We present an interim analysis of the first prospective study in which Plerixafor was administered on-demand in patients affected by multiple myeloma and lymphoma who received high dose cyclophosphamide or DHAP (dexamethasone, cytarabine, cisplatin) plus G-CSF to mobilize peripheral blood stem cells (PBSC). One hundred and two patients were evaluable for response. A cohort of 240 patients receiving the same mobilizing chemotherapy was retrospectively studied. Failure to mobilize CD34(+) cells in peripheral blood was reduced by 'on-demand' strategy compared to conventional mobilization; from 13·0 to 3·0% (P = 0·004). Failure to harvest CD34(+) cells 2 × 10(6) /kg decreased from 20·9 to 4·0% (P = 0·0001). The on-demand Plerixafor strategy also resulted in a lower rate of mobilization failure (P = 0·03) and harvest failure (P = 0·0008) when compared to a 'bias-adjusted set of controls'. Evaluation of economic costs of the two strategies showed that the overall cost of the two treatments were comparable when salvage mobilizations were taken into account. When in combination with cyclophosphamide or DHAP plus G-CSF, the 'on-demand' use of Plerixafor showed, in comparison to conventionally treated patients, a significant improvement in mobilization of PBSC with no increase in overall cost.