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Dosing Strategies for Plerixafor in Patients with Multiple Myeloma with Renal Impairment: A Single Center Experience

Year: 2025

Type: article

Abstract: Introduction Plerixafor , an inhibitor of CXCR4 chemokine receptor , is frequently given to patients with multiple myeloma (MM) for mobilization prior to autologous hematopoietic cell transplantation (HCT). Standard dosing is 0.24 mg/kg daily for up to 4 days with a maximum dose of 40 mg/day. Renal dose adjustments (0.16 mg/kg daily) are suggested in patients with an estimated creatinine clearance [CrCL] less than or equal to 50 mL/min. Renal impairment is common in patients with MM and there is little data regarding plerixafor dosing for safety and efficacy. Current practice at Moffitt Cancer Center is for patients with poor renal function (CrCL <50 mL/min) to receive dose adjustments. Here, we describe our experience and outcomes with both dosing strategies in a large MM HCT population. Methods All consecutive MM patients with a CrCL of less than 50 mL/min (calculated using the Cockcroft-Gault method) who received plerixafor between 2015 and 2023 were included in our analysis. Data collection included the following: disease state, age, gender, height, weight, serum creatinine, number of CD34 cells collected, GCSF dose, number of GCSF doses administered, plerixafor dose, and number of plerixafor doses administered. In patients with an estimated CrCL of less than 50 mL/min, comparisons were made between renal adjusted (RA) and standard dosed (SD) patients. The final outcome for each group was successful collection, defined as meeting the target of greater than 4 × 10 6 CD34+ cells/kg. Results From 2015 to 2023, 165 patients had an estimated CrCL of less than 50 mL/min. In renally impaired patients (Table 1), on the day of plerixafor administration, the majority received RA doses (n=137) while 28 patients received SD dose of 24 mg. In the overall group, most were female (58.2%), with a median age of 65 years (range, 40-81 years), a median serum creatinine of 2 mg/dL (0.8-11.4), and a median CrCl of 36.1 mL/min (range, 4.7 – 49.8 mL/min). In RA patients, the median number of plerixafor doses given was 1 (range, 1-4), median number of apheresis collection days was 1 (range, 1-4 days), and the median final CD34 million cells/kg count was 6.04 (0.11 – 19.1). In SD patients, the median number of plerixafor doses given was 1 (range, 1-3), median number of apheresis collection days was 1 (range, 1-3 days), and the median final CD34 million cells/kg count was 5.55 (0.33 – 15.6). Regarding the proportion of successful collections, 89.8.% in RA patients and 89.3% in SD patients achieved goal collection ( p =1). Conclusion We report plerixafor dosing on a large cohort of MM patients undergoing apheresis prior to HCT. Our results indicate that renally adjusting the plerixafor in patients with a CrCL <50 mL/min also achieves similar collections as those who receive standard dosing plerixafor.

Source: Transplantation and Cellular Therapy

DOI: 10.1016/j.jtct.2025.01.296