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

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.