P2 3-year observation study of Plerixafor use in New Zealand

INTRODUCTION: Plerixafor, a novel CXCR4 pathway antagonist, is used to mobilise CD34-positive stem cells for autologous stem cell transplantation to treat haematological malignancy. Data regarding the rates of failure to mobilise and frequency of use of Plerixafor vary widely. METHODS: This retrospective study reviewed 203 consecutive patients with myeloma (n = 122) or lymphoma (n = 81) undergoing peripheral blood stem cell mobilisation between 1/1/2016 and 5/8/2019 at a New Zealand hospital using data from an institution transplant database and the electronic medical record. Patients with myeloma were mobilised using cyclophosphamide and G-CSF after induction chemotherapy with cyclophosphamide, bortezomib and dexamethasone. Patients with lymphoma were mobilised with G-CSF after induction or salvage chemotherapy according to disease type. Patients failing to mobilise sufficient stem cells either received “pre-emptive” Plerixafor added to G-CSF +/- chemotherapy during the 1st attempt or were re-mobilised after a 4-week break with Plerixafor and G-CSF alone. RESULTS: The success rate of mobilisation for lymphoma and myeloma patients at first attempt was 79% and 87% respectively. Plerixafor allowed successful harvest for 5 of 7 lymphoma patients and 8 of 9 myeloma patients who failed to harvest at first attempt, resulting in 88% and 94% of all patients having a successful harvest on either first or second attempt, respectively. Age greater than 60 years was a risk factor for failed mobilisation in lymphoma patients. CONCLUSION: This study shows that an approach using pre-emptive and rescue Plerixafor is effective and allows haematopoietic stem cell mobilisation for ≥88% of patients. Further research is required to establish the optimal strategy for its use.