Emilumenib

Acute myeloid leukaemias harbouring a rearrangement of the mixed lineage leukaemia gene (MLL) are aggressive haematopoietic malignancies that relapse early and have a poor prognosis (event-free survival less than 50%). Menin is a tumour suppressor, however, in MLL-rearranged leukaemias it functions as a co-factor which is mandatory for the leukaemic transformation by interaction with the N-terminal part of MLL, which is maintained in all MLL-fusion proteins. Inhibition of menin blocks leukaemogenesis and leads to differentiation and, in turn, to apoptosis of leukaemic blasts. Furthermore, nucleophosmin 1 (NPM1) binds to specific chromatin targets, which are co-occupied by MLL, and menin inhibition has been shown to trigger degradation of mNPM1 resulting in a rapid decrease in gene expression and activating histone modifications. Therefore, disruption of the menin-MLL axis blocks leukaemias driven by NPM1 mutations for which the expression of menin-MLL target genes (e.g., MEIS1, HOX etc.) is essential. To date at least six different menin-MLL inhibitors are undergoing clinical evaluation as first- and second-line monotherapy in acute leukaemias: DS-1594, BMF-219, JNJ-75276617, DSP-5336, revumenib, and ziftomenib, however, only for revumenib and ziftomenib early clinical data have been reported. In the revumenib phase I/II AUGMENT-101 trial (N = 68) with very heavily pretreated AML patients the ORR was 53% with a CR rate of 20%. The ORR in patients harbouring MLL rearrangement of mNPM1 was 59%. Patients who achieved a response had a mOS of 7 months. Similar results have been reported for ziftomenib in the phase I/II COMET-001 trial. ORR was 40% and CRc was 35% in AML patients with mNPM1. However, outcome was worse in AML patients with a MLL rearrangement (ORR 16.7%, CRc 11%). Differentiation syndrome was a notable adverse event. The clinical development of novel menin-MLL inhibitors is well in line with the currently ongoing paradigm shift towards targeted therapies seen in the AML treatment landscape. Moreover, the clinical assessment of combinations of these inhibitors with established therapy options in AML could be the fuel for an improved outcome of MLL/NPM1 patients.

Menin inhibitors are a class of targeted agents that exemplify how a deeper understanding of leukemia pathogenesis can unify seemingly distinct genetic acute leukemia subgroups under a common therapeutic strategy. In particular, acute leukemia with NPM1 mutations (NPM1m) and KMT2A rearrangements (KMT2Ar) represent the primary targets of this emerging drug class. Acute myeloid leukemia (AML) with NPM1m—which accounts for approximately 30% of AML cases and AML or acute lymphoblastic leukemia (ALL) with KMT2Ar—and is present in 5–10% of cases, shares a common pathogenetic mechanism: the aberrant activation of the MEIS1–HOXA axis. These leukemic subsets are associated with poor prognosis, particularly in the relapsed/refractory (R/R) setting. For KMT2Ar AML, the prognosis is especially dismal, with a median overall survival (OS) of 2.4 months and a complete remission (CR) rate of only 5%. In NPM1m AML, intensive chemotherapy achieves remission in approximately 80% of cases, but relapse remains a major challenge, occurring in nearly 50% of patients. Relapsed NPM1m AML is linked to a poor prognosis, with a median OS of 6.1 months (12-month OS: 30%) and a median relapse-free survival (RFS) of 5.5 months (12-month RFS: 34%). Menin inhibitors directly target the leukemogenic transcriptional program driven by HOX and MEIS1, disrupting oncogenic signaling and offering a promising therapeutic approach for these high-risk patients. This class of agents has rapidly progressed through clinical development, showing promising antileukemic activity in both treatment-naïve and R/R AML. Currently, six menin inhibitors are in clinical evaluation as monotherapy or in combination regimens: revumenib, ziftomenib, bleximenib (previously JNJ-75276617), enzomenib (previously DSP-5336), DS-1594, and BMF-219. In this review, we critically analyze the clinical development and therapeutic potential of the four most extensively studied menin inhibitors—revumenib, ziftomenib, bleximenib, and enzomenib. We discuss their efficacy, safety profiles, and potential roles within the current treatment algorithm. The continued clinical evaluation of menin inhibitors may redefine treatment paradigms for NPM1m and KMT2Ar AML and other acute leukemia with the aberrant MEIS1-HOXA axis, offering new hope for patients with limited therapeutic options.