SUMMARY: The FDA on November 15, 2024, approved Revumenib (REVUFORJ®), a menin inhibitor, for Relapsed or Refractory acute leukemia with a lysine methyltransferase 2A gene (KMT2A) translocation in adult and pediatric patients 1 year and older. The American Cancer Society estimates that in 2024, 20,800 new cases of Acute Myeloid Leukemia (AML) will be diagnosed in the United States and 11,220 patients will die of the disease. AML is one of the most common types of leukemia in adults and can be considered as a group of molecularly heterogeneous diseases with different clinical behavior and outcomes. A significant percentage of patients with newly diagnosed AML are not candidates for intensive chemotherapy or have disease that is refractory to standard chemotherapy. Even with the best available therapies, the 5-year Overall Survival in patients 65 years of age or older is less than 5%. Cytogenetic analysis has been part of routine evaluation when caring for patients with AML. By predicting resistance to therapy, tumor cytogenetics will stratify patients based on risk, and help manage them accordingly. Even though cytotoxic chemotherapy may lead to long term remission and cure in a minority of patients with favorable cytogenetics, patients with high-risk features such as unfavorable cytogenetics, molecular abnormalities, prior myelodysplasia, and advanced age, have poor outcomes with conventional chemotherapy alone. More importantly, with the understanding of molecular pathology of AML, personalized and targeted therapies are becoming an important part of the AML treatment armamentarium. Over 50% of AML cases lack targetable mutations, relying instead on toxic chemotherapy.
Rearrangements of KMT2A gene previously known as MLL are found in 80% of infant Acute Lymphoblastic Leukemia (ALL) and in 5-15% of acute leukemia cases in children and adults, including myeloid, lymphoid, or mixed phenotypes. NPM1 mutations are the most common genetic alteration in adult Acute Myeloid Leukemia (AML), occurring in up to 30% of cases. Acute leukemias with KMT2A rearrangements have a poor prognosis, with a 5-year overall survival rate of less than 25%. There are no targeted therapies currently approved specifically for acute leukemia with KMT2A gene rearrangements or NPM1 mutations. Both KMT2A gene rearrangements and NPM1 mutations cause blood cells to regress to a stem-cell-like state, leading to the formation of leukemia cells. For leukemias driven by KMT2A gene rearrangements and NPM1 mutations, menin is a critical oncogenic cofactor. Menin interacts with the protein MLL1 (produced by KMT2A), forming a menin–MLL1 complex. This complex binds to chromatin and activates aberrant gene pathways, specifically HOX genes and their cofactor MEIS1, critical for leukemia development.
Revumenib is a potent, oral, small molecule menin inhibitor. It blocks the menin–MLL1 interaction, preventing the formation of the menin–MLL1 complex. By disrupting this complex, Revumenib stops the aberrant activation of HOX and MEIS1 gene expression and allows leukemia cells to either die or differentiate back into normal blood cells. Unlike other targeted therapies that block dysfunctional proteins, Revumenib prevents aberrant gene expression at its source. Its ability to target a common mechanism in AML makes it broadly applicable. Preclinical Studies demonstrated that menin inhibition reverses leukemia progression by downregulating HOX and MEIS1 transcription disrupting oncogenic complexes formed by either option for patients with KMT2A gene arrangements or NPM1-mutated AML. Revumenib showed dramatic antileukemic activity, making this agent promising.
AUGMENT-101 is a single-arm cohort of an open-label, multicenter trial which included 104 adult and pediatric patients (at least 30 days old) with Relapsed or Refractory (R/R) acute leukemia with a KMT2A translocation. Eligible patients had a corrected QT interval of less than 450 milliseconds and those with an11q23 partial tandem duplication were excluded. Revumenib was administered at a dose that was approximately equivalent to 160 mg in adults orally twice daily. Treatment was continued until progressive disease, unacceptable toxicity, failure to achieve a morphological leukemia-free state by 4 cycles of treatment, or Hematopoietic Stem Cell Transplantation (HSCT). The median patient age was 37 years, 83% of patients had AML, 15% had Acute Lymphoblastic Leukemia, and 2% had mixed phenotype acute leukemia. Approximately 59% had relapsed/refractory disease, 21% had primary refractory disease, 20% of patients had untreated relapsed disease and 44% of patients underwent prior HSCT. The main efficacy outcome measures were Complete Remission (CR) plus CR with partial hematologic recovery (CRh), the duration of CR plus CRh, and conversion from transfusion dependence to independence.
The CR plus CRh rate was 21.2%, and the median CR plus CRh duration was 6.4 months. Of the 22 patients achieving CR or CRh, the median time to CR or CRh was 1.9 months. Among the 83 patients dependent on RBC and/or platelet transfusions at baseline, 14% became independent of RBC and platelet transfusions during any 56-day post-baseline period. Of the 21 patients independent of both RBC and platelet transfusions at baseline, 48% remained transfusion independent during any 56-day post-baseline period. The most common adverse reactions noted in this study were hemorrhage, nausea, increased phosphate, musculoskeletal pain, neutropenia, infection, elevated liver enzymes, differentiation syndrome, QT prolongation and fatigue.
It was concluded that Revumenib is the first menin inhibitor and its efficacy represents a substantial improvement over previously available therapies, and represents a major breakthrough for patients with Relapsed or Refractory acute leukemia with a KMT2A translocation.
https://www.fda.gov/drugs/resources-information-approved-drugs/fda-approves-revumenib-relapsed-or-refractory-acute-leukemia-kmt2a-translocation
