Introduction: Registry data do not provide sufficient information on appropriate waiting time before kidney transplantation (KTx) among patients with multiple myeloma (MM) after autologous stem cell transplantation (ASCT), acceptable MM treatment response prior to KTx, and the outcomes after KTx.
Methodology:  We retrospectively reviewed the characteristics and outcomes of MM patients who underwent KTx at our centre between 2010 to 2023. 
Results: 8 patients were included in the study. All patients were staged as International Staging System III, with 1 patient having high risk cytogenetics (t (4;14) and deletion 17p). Five were in complete remission (CR) before KTx, 2 were in very good partial remission (VGPR), and 1 had MM relapse after ASCT requiring lenalidomide/dexamethasone and achieved VGPR prior to KTx. One-half of the patients were recipients of a living donor kidney, including 1 ABO incompatible (ABOi) KTx.  Median waiting time to KTx after ASCT was 42 months (range 28-64 months). Maintenance therapy was present for 3 patients at time of KTx (each received ixazomib, dexamethasone and thalidomide respectively). All 8 patients were induced with basiliximab for KTx, with the ABOi KTx patient receiving 4 additional plasmapheresis and intravenous immunoglobulin for desensitization. During median follow up of 41 months (range 14 to 127 months), 3 patients developed biopsy proven acute rejection at 2, 8 and 25 months respectively, but none had graft loss from allograft rejection and all had recovery of kidney function to baseline after treatment. Four (50%) patients had MM relapse at 6, 8, 17 and 26 months respectively. There were 2 graft losses, both were secondary to MM relapses, 1 developed graft loss at time of MM relapse diagnosis and 1 developed graft loss from refractory and progressive MM 64 months after relapse diagnosis. Death-censored graft survival at 1, 3 and 5 years after KTx were 100%, 83%, and 83% respectively. Overall survival at 1, 3 and 5 years after KTx were 100%, 67% and 50% respectively. All 4 patients died of infection related causes, and 3 of them had MM relapse prior to death. Compared to patients with CR prior to KTx, patients with VGPR did not differ in MM relapses and overall survival. 
Conclusion: Early MM relapse after KTx is common. Compared to patients who achieved CR prior to KTx, those who achieved VGPR had similar outcomes after KTx. KTx provides reasonable survival benefit to MM patients.