Motixafortide plus granulocyte colony-stimulating factor (G-CSF) mobilized significantly more CD34+ hematopoietic stem and progenitor cells (HSPCs) within two apheresis procedures compared with placebo plus G-CSF among patients with multiple myeloma (MM) undergoing autologous hematopoietic stem cell transplantation (AHSCT), according to results from the phase III GENESIS trial.
“Moreover, extended CXCR4 inhibition with motixafortide preferentially mobilized increased numbers of immunophenotypically and transcriptionally primitive HSPCs,” said lead author Zachary Crees, MD, of the Washington University School of Medicine in St. Louis, Missouri. The data were reported in Nature Medicine.
The study enrolled 122 patients with MM undergoing AHSCT across 18 centers. Patients were randomized two-to-one to receive either motixafortide or placebo plus G-CSF. The primary endpoint was the number of patients who collected ≥6 × 106 CD34+ cells kg–1 in two apheresis procedures, with a secondary endpoint of collecting the same number of cells in one procedure.
Reportedly, 92.5% of participants in the motixafortide group reached the primary endpoint compared with 26.2% in the placebo group (odds ratio [OR], 53.3; 95% CI, 14.20-201.33; P<.0001). Furthermore, 88.8% of patients in the motixafortide group met the secondary endpoint compared with 9.5% of those in the placebo group (OR, 118.0; 95% CI, 25.36-549.35; P<.0001).
The motixafortide regimen was generally safe and well tolerated, the investigators wrote. Transient grade 1 or 2 injection site reactions were the most common treatment-emergent adverse events.
“The upfront use of a single injection of motixafortide added to G-CSF resulted in rapid, robust, and reliable mobilization of optimal numbers of CD34+ HSPCs,” Dr. Crees and colleagues concluded.
Reference
Crees ZD, Rettig MP, Jayasinghe RG, et al. Motixafortide and G-CSF to mobilize hematopoietic stem cells for autologous transplantation in multiple myeloma: a randomized phase 3 trial. Nat Med. 2023;29(4):869-879. doi:10.1038/s41591-023-02273-z