enzomenib (DSP-5336)

P1, N=8, Not yet recruiting, Sumitomo Pharma America, Inc.

While differentiation therapy revolutionized acute promyelocytic leukemia (APL) with all-trans retinoic acid (ATRA) and arsenic trioxide (ATO), its extension into non-APL AML has been limited until recent targeted agents...IDH1/2 inhibitors (ivosidenib, enasidenib, olutasidenib) yield overall response rates (ORRs) of 30-94% in AML with DS in 10-19%. Menin inhibitors (revumenib, ziftomenib, enzomenib, bleximenib) achieve ORRs of 33-88% in KMT2A-rearranged or NPM1-mutated AML, with DS in 10-25% and QT prolongation as key toxicities. FLT3 inhibitors (gilteritinib, quizartinib) improve survival in FLT3-mutated AML with DS in 1-5%...Improved recognition of DS and rational combination approaches will be essential to maximize the therapeutic benefit. Future research should address mechanisms of resistance and biomarkers to achieve cures beyond APL.

Revumenib received approval in 2024-2025 for relapsed or refractory KMT2A-rearranged acute leukemia and NPM1-mutated AML...Several menin inhibitors, including ziftomenib, bleximenib, and enzomenib, are in clinical development...Combination therapies with azacitidine and venetoclax or intensive chemotherapy have achieved high response rates in newly diagnosed patients, supporting their potential use in frontline treatment...Approximately 30-40% of responders in relapsed or refractory trials proceeded to allogeneic transplantation, which remains a key pathway to potential cure. This review examines the molecular mechanisms of the menin-KMT2A interaction, and summarizes clinical trial data on the efficacy and safety of menin inhibitors as monotherapy and in combination.

P2, N=53, Not yet recruiting, Australasian Leukaemia and Lymphoma Group

Menin inhibitor approval/use is expanding into other HOX-driven subtypes (e.g. NPM1, NUP98r), as frontline option and in combination settings. Monitoring for differentiation syndrome, QT interval prolongation, recognizing pseudo-progression, and supportive care needs remains essential to maximize patient benefit.

Next-generation agents (ziftomenib, bleximenib, enzomenib, BMF-219) have displayed similar composite complete remission rates (20-35%) and overall response rates (45-65%) in heavily pretreated KMT2Ar and NPM1m acute myeloid leukemia (AML) with measurable residual disease (MRD) negativity and prolonged overall survival (5-7 months)...Acquired mutations in the menin gene described in 39% of post-revumenib relapses have not been identified following other inhibitors (ziftomenib, bleximenib), prompting new questions about resistance mechanisms. These promising results swiftly led to the launch of multiple trials of menin inhibitors combined with intensive (cytarabine and anthracycline) and nonintensive (venetoclax and hypomethylating) chemotherapy backbones...Ongoing/pending phase 3 trials will clarify whether menin blockade should be incorporated into frontline and maintenance regimens for all patients with KMT2A rearranged or NPM1 mutant disease. In the current era, menin inhibition remains a key pillar of the success of precision medicine for AML therapy.

These findings justify the integration of menin inhibitors into the AML therapeutic landscape, and support ongoing randomized trials to confirm their benefit in both frontline and relapse or refractory settings.

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. 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.

Following the promising outcomes of the two pioneering menin inhibitors, revumenib and ziftomenib, other menin inhibitors, including bleximenib, enzomenib, BN-104 and HMPL-506 are currently under investigation in clinical trials. Several trials presented their initial outcomes at the 2024 ASH Annual Meeting. This review highlights the key outcomes of these pivotal clinical trials.

Menin inhibitors demonstrate promising clinical activity in molecularly defined leukemias, with Revumenib establishing proof-of-concept for this therapeutic approach. However, challenges remain, including resistance development, optimal timing of therapy initiation, and determination of effective combination strategies. Larger randomized trials with extended follow-up are needed to establish long-term efficacy and safety profiles. The rapid clinical development of multiple agents in this class suggests an expanding role for Menin inhibitors in leukemia treatment paradigms.

At the 2024 ASH annual meeting, updated clinical data regarding monotherapy with MENINis in AL, including revumenib, bleximenib, enzomenib and BN104, were presented. Furthermore, the therapeutic effects of venetoclax plus azacitidine or "3 + 7" regimens were further enhanced by the addition of MENINis in KMT2Ar- and NPM1m-AML patients. Therefore, MENINis offer new therapeutic prospects for AML patients, particularly for those with high-risky and poor-prognostic on-target subtypes.

P1/2, N=362, Recruiting, Sumitomo Pharma America, Inc. | N=70 --> 362 | Trial completion date: Feb 2025 --> Oct 2027 | Trial primary completion date: Jan 2025 --> Apr 2027