Partanen, Anu, Waage, Anders, Peceliunas, Valdas, Schjesvold, Fredrik, Anttila, Pekka, Säily, Marjaana, Uttervall, Katarina, Putkonen, Mervi, Carlson, Kristina, Haukas, Einar, Sankelo, Marja, Szatkowski, Damian, Hansson, Markus, Marttila, Anu, Svensson, Ronald, Axelsson, Per, Lauri, Birgitta, Mikkola, Maija, Karlsson, Conny, and Abelsson, Johanna
Simple Summary: Outcomes for high-risk myeloma patients are still poor, despite many advances in treatment. In addition, scarce data exist on double maintenance in transplant-eligible high-risk newly diagnosed multiple myeloma (NDMM) patients. We present the results of a prospective study on 120 transplant-eligible NDMM patients with prolonged cytogenetic risk-based all-oral maintenance with lenalidomide + ixazomib (IR) for high-risk patients and lenalidomide (R) alone for non-high-risk patients after ixazomib–lenalidomide–dexamethasone (IRD) induction plus autologous stem cell transplantation followed by IRD consolidation. We found that high-risk cytogenetics had no impact on the proportion of patients achieving sustained undetectable minimal residual disease or on the rate of progression-free survival with IR maintenance. Our data suggest that prolonged use of all-oral double maintenance with IR with reasonable adverse effects would be a potential option for high-risk myeloma patients. Scarce data exist on double maintenance in transplant-eligible high-risk (HR) newly diagnosed multiple myeloma (NDMM) patients. This prospective phase 2 study enrolled 120 transplant-eligible NDMM patients. The treatment consisted of four cycles of ixazomib–lenalidomide–dexamethasone (IRD) induction plus autologous stem cell transplantation followed by IRD consolidation and cytogenetic risk-based maintenance therapy with lenalidomide + ixazomib (IR) for HR patients and lenalidomide (R) alone for NHR patients. The main endpoint of the study was undetectable minimal residual disease (MRD) with sensitivity of <10−5 by flow cytometry at any time, and other endpoints were progression-free survival (PFS) and overall survival (OS). We present the preplanned analysis after the last patient has been two years on maintenance. At any time during protocol treatment, 28% (34/120) had MRD < 10−5 at least once. At two years on maintenance, 66% of the patients in the HR group and 76% in the NHR group were progression-free (p = 0.395) and 36% (43/120) were CR or better, of which 42% (18/43) had undetectable flow MRD <10−5. Altogether 95% of the patients with sustained MRD <10−5, 82% of the patients who turned MRD-positive, and 61% of those with positive MRD had no disease progression at two years on maintenance (p < 0.001). To conclude, prolonged maintenance with all-oral ixazomib plus lenalidomide might improve PFS in HR patients. [ABSTRACT FROM AUTHOR]