ivosidenib and enasidenib

There has been extraordinary progress in the field of targeted therapy for myeloid malignancies in the last few years, especially due to the approval of various agents that can be used as monotherapy or in combination as first-line treatment or when facing a refractory or relapsed disease. Many successful trials have been conducted recently, and a consistent body of work about the efficacy of novel molecules is now available. In this review, we sought to explain how enasidenib and ivosidenib have changed the face of myeloid neoplasm treatment through isocitrate dehydrogenase inhibition and to summarize the trials results that have led to the current commercial indications for the two molecules.

Topics: Aminopyridines; Glycine; Humans; Isocitrate Dehydrogenase; Middle Aged; Pyridines; Triazines

The isocitrate dehydrogenases enzymes, IDH1 and IDH2, catalyze the conversion of isocitrate to α-ketoglutarate (αKG) in the cell cytoplasm and mitochondria, respectively, and contribute to generating the dihydronicotinamide-adenine dinucleotide phosphate (NADPH) as reductive potential in different cellular processes. Mutations in IDH1 and IDH2 genes are found collectively in about 20-25% of acute myeloid leukemia (AML) patients. Mutant IDH enzymes have neomorphic activity and convert αKG to the oncometabolite R-2-hydroxyglutarate (R-2-HG) which accumulates at high levels in the cell and hampers the function of αKG-dependent enzymes, including epigenetic regulators, thus leading to altered gene expression and block of differentiation and contributing to leukemia development. Inhibition of the neomorphic mutants induces marked decrease in R-2-HG levels and restores myeloid differentiation. Enasidenib and ivosidenib are potent and selective inhibitors of mutant IDH2 and IDH1, respectively, act as differentiating agents and showed clinical activity in relapsed/refractory (R/R) AML harboring the specific mutation. As single agents, both drugs have been approved by the Food and Drug Administration (FDA) for the treatment of R/R AML. The relevance of IDH targeting within either single agent approach or, most importantly, combinatorial treatments in AML will be discussed.

Topics: Aminopyridines; Antineoplastic Agents; Cell Differentiation; Clinical Trials as Topic; Glutarates; Glycine; Humans; Isocitrate Dehydrogenase; Isocitrates; Ketoglutaric Acids; Leukemia, Myeloid, Acute; Multicenter Studies as Topic; Mutation, Missense; NADP; Pyridines; Syndrome; Triazines

The therapeutic landscape is rapidly changing, with eight new drugs approved by the Food and Drug Administration within the last 2 years, including midostaurin and gilteritinib for FLT3 mutant newly diagnosed and relapsed/refractory (R/R) acute myeloid leukemia (AML), respectively; CPX-351 (liposomal cytarabine and daunorubicin) for therapy-related AML and AML with myelodysplasia-related changes; gemtuzumab ozogamicin (anti-CD33 monoclonal antibody conjugated with calicheamicin) for newly diagnosed and R/R CD33-positive AML; enasidenib and ivosidenib for IDH2 and IDH1 mutant R/R AML, respectively. Novel therapies have also emerged for newly diagnosed AML in adults who are age 75 years or older, or who have comorbidities that preclude the use of intensive induction chemotherapy. These include venetoclax (BCL-2 inhibitor) in combination with hypomethylating agents (azacitidine or decitabine) or low-dose cytarabine (LDAC), and glasdegib (sonic hedgehog pathway inhibitor) in combination with LDAC. This flurry of new drug approvals has markedly altered the treatment landscape in AML and provided new opportunities, as well as new challenges for treating clinicians. This review will focus on how these drugs might shape clinical practice and the hurdles likely to be faced by new therapies seeking entry into this dynamic and rapidly changing therapeutic landscape.

Topics: Aminopyridines; Aniline Compounds; Cytarabine; Daunorubicin; fms-Like Tyrosine Kinase 3; Gemtuzumab; Glycine; Humans; Leukemia, Myeloid, Acute; Pyrazines; Pyridines; Staurosporine; Triazines; United States; United States Food and Drug Administration

The prognosis of adult acute myeloid leukemia (AML) remains poor, with the long-term survival rate less than 50%. However, the current paradigms of treatment are changing through a better understanding of the disease genetics and pathophysiology. Since 2017, eight new drugs have been approved by the U.S. Food and Drug Administration for the treatment of AML, including the FLT3 inhibitors midostaurin and gilteritinib, the IDH inhibitors ivosidenib and enasidenib, the anti-CD33 monoclonal antibody gemtuzumab ozogamicin, liposomal daunorubicin and cytarabine, the hedgehog pathway inhibitor glasdegib and the BCL-2 inhibitor venetoclax. Preclinical data demonstrated the anti-leukemic efficacy of venetoclax in AML and its synergy when combined with hypomethylating agents or chemotherapy agents. Clinical trials have demonstrated the clinical benefit of venetoclax-based therapies in newly diagnosed AML, leading to the recent FDA approval of venetoclax in combination with hypomethylating agents or low-dose cytarabine for older adults with newly diagnosed AML. Herein, we focus on the role of single-agent BCL-2 inhibition in AML and review the clinical studies of venetoclax-based combination regimens and the evolving mechanisms of resistance.

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Benzimidazoles; Bridged Bicyclo Compounds, Heterocyclic; Clinical Trials as Topic; Cytarabine; Daunorubicin; Glycine; Humans; Leukemia, Myeloid, Acute; Phenylurea Compounds; Proto-Oncogene Proteins c-bcl-2; Pyridines; Sulfonamides; Triazines

Acute myeloid leukemia (AML) is a heterogeneous disease. Until recently, treatment for patients with AML was limited to induction chemotherapy with cytarabine and anthracycline or hypomethylating agents, and, in some instances, allogeneic hematopoietic stem cell transplant. With the recent approval of new therapies-i.e., CPX-351, enasidenib, ivosidenib, gemtuzumab ozogamicin, and midostaurin-a new era in AML treatment has emerged. Comprehensive diagnostic testing, such as cytogenetic and molecular testing, is necessary for establishing patient eligibility for these new agents and should be performed in a timely manner. However, choosing a therapy for patients who are eligible for multiple treatments may be a complex process, particularly for patients with newly diagnosed AML. This review discusses data, including associated safety profiles that supported these recent approvals, and provides insights to help clinicians navigate new therapy options for this devastating disease. Given the heterogeneity of AML, the treatment landscape will likely continue to grow and evolve as additional agents (and their combinations) are approved for the treatment of subpopulations of patients with AML. Physicians will need to remain abreast of the ever-changing treatment landscape.

Topics: Aminoglycosides; Aminopyridines; Antibodies, Monoclonal, Humanized; Cytarabine; Daunorubicin; Female; Gemtuzumab; Glycine; Humans; Leukemia, Myeloid, Acute; Male; Pyridines; Staurosporine; Triazines

Mutant isocitrate dehydrogenase 1/2 (mIDH1/2) proteins catalyze production of the oncometabolite D-2-hydroxyglutarate (2-HG). Ivosidenib and enasidenib are oral inhibitors of mIDH1 and mIDH2, respectively. An open-label phase 1 study is evaluating the safety and efficacy of ivosidenib or enasidenib combined with intensive induction and consolidation chemotherapy in adult patients with newly diagnosed mIDH1/2 acute myeloid leukemia (AML; NCT02632708). In this population, we characterized the pharmacokinetics (PK), pharmacodynamics (PD), and PK/PD relationships for ivosidenib and enasidenib. Patients received continuous oral ivosidenib 500 mg once daily or enasidenib 100 mg once daily combined with chemotherapy. Serial blood samples were collected for measurement of the concentrations of the mIDH inhibitors. 2-HG concentrations were measured in both plasma and bone marrow aspirates. Samples were collected from 60 patients receiving ivosidenib and 91 receiving enasidenib. For both drugs, exposures at steady state were higher than after single doses, with mean accumulation ratios (based on area under the plasma concentration-time curve from time 0 to 24 hours) of 2.35 and 8.25 for ivosidenib and enasidenib, respectively. Mean plasma 2-HG concentrations were elevated at baseline. After multiple ivosidenib or enasidenib doses, mean trough plasma 2-HG concentrations decreased to levels observed in healthy individuals and were maintained with continued dosing. There was a corresponding reduction in bone marrow 2-HG concentrations. When combined with intensive chemotherapy in patients with newly diagnosed mIDH1/2 AML, ivosidenib and enasidenib demonstrated PK/PD profiles similar to those when they are given as single agents. These findings support the dosing of ivosidenib or enasidenib in combination with intensive chemotherapy for the treatment of patients with newly diagnosed mIDH1/2 AML.

Topics: Adult; Aminopyridines; Antineoplastic Agents; Consolidation Chemotherapy; Glycine; Humans; Isocitrate Dehydrogenase; Leukemia, Myeloid, Acute; Mutation; Pyridines; Triazines

Ivosidenib (AG-120) and enasidenib (AG-221) are targeted oral inhibitors of the mutant isocitrate dehydrogenase (mIDH) 1 and 2 enzymes, respectively. Given their effectiveness as single agents in mIDH1/2 relapsed or refractory acute myeloid leukemia (AML), this phase 1 study evaluated the safety and efficacy of ivosidenib or enasidenib combined with intensive chemotherapy in patients with newly diagnosed mIDH1/2 AML. Ivosidenib 500 mg once daily and enasidenib 100 mg once daily were well tolerated in this setting, with safety profiles generally consistent with those of induction and consolidation chemotherapy alone. The frequency of IDH differentiation syndrome was low, as expected given the concurrent administration of cytotoxic chemotherapy. In patients receiving ivosidenib, the frequency and grades of QT interval prolongation were similar to those observed with ivosidenib monotherapy. Increases in total bilirubin were more frequently observed in patients treated with enasidenib, consistent with this inhibitor's known potential to inhibit UGT1A1, but did not appear to have significant clinical consequences. In patients receiving ivosidenib (n = 60) or enasidenib (n = 91), end-of-induction complete remission (CR) rates were 55% and 47%, respectively, and CR/CR with incomplete neutrophil or platelet recovery (CR/CRi/CRp) rates were 72% and 63%, respectively. In patients with a best overall response of CR/CRi/CRp, 16/41 (39%) receiving ivosidenib had IDH1 mutation clearance and 15/64 (23%) receiving enasidenib had IDH2 mutation clearance by digital polymerase chain reaction; furthermore, 16/20 (80%) and 10/16 (63%), respectively, became negative for measurable residual disease by multiparameter flow cytometry. This trial was registered at www.clinicaltrials.gov as #NCT02632708.

Topics: Adult; Aged; Aminopyridines; Antineoplastic Agents; Female; Glycine; Humans; Isocitrate Dehydrogenase; Leukemia, Myeloid, Acute; Male; Middle Aged; Mutation; Pyridines; Treatment Outcome; Triazines; Young Adult

Two novel inhibitors of isocitrate dehydrogenase (IDHi), ivosidenib and enasidenib, significantly improve survival for AML patients with an IDH1 or IDH2 mutation, respectively; however, rash has been reported as a toxicity of IDHi. The objective of our study is to determine the incidence, grade, clinical, and histopathologic features of dermatologic adverse events (DAEs) secondary to IDHi. This study is a retrospective analysis of 169 patients who were treated with either ivosidenib or enasidenib as single agent or in combination with induction chemotherapy at Memorial Sloan Kettering Cancer Center from January 1, 2013 to April 1, 2021. DAEs thought to be possibly, probably, or definitely related to IDHi occurred in 55 of 169 patients [0.32, 95 % CI: 0.25 - 0.40]. Of a total 81 DAEs observed, the most common DAE types were inflammatory dermatoses (27 %); cutaneous vascular manifestations (8%); cutaneous infections (7%); and pruritus (2%). Notably, 50% of infections and 15.5% of rashes were high grade. Knowledge of these findings is critical to optimize the treatment and quality of life of patients with AML on IDHi.

Topics: Enzyme Inhibitors; Humans; Isocitrate Dehydrogenase; Leukemia, Myeloid, Acute; Mutation; Quality of Life; Retrospective Studies

The development and approval of novel substances have resulted in substantial improvements in the treatment of acute myeloid leukemia (AML). In the current era of novel treatment options, genetic and molecular testing at the time of diagnosis and relapse becomes increasingly relevant. Midostaurin in combination with intensive chemotherapy is the standard of care as upfront therapy in younger AML patients with mutated fms-related tyrosine kinase 3 (FLT3). Gilteritinib, a second- generation FLT3 inhibitor, represents a key drug for relapsed/refractory (R/R) FLT3-mutated AML patients. Targeted therapy has also been developed for patients with mutated isocitrate dehydrogenase 1 (IDH1) and IDH2. The US Food and Drug Administration (FDA) approved ivosidenib as a monotherapy for newly diagnosed older adult IDH1-mutated patients and enasidenib for R/R IDH2-mutated AML patients. CPX-351, a liposomal formulation of daunorubicin and cytarabine, has become an important upfront treatment strategy for fit patients with therapy-related AML or AML with myelodysplasia-related changes that are generally challenging to treat. The antibody drug conjugate gemtuzumab ozogamicin was approved in combination with intensive therapy for patients with newly diagnosed (FDA/European Medicines Agency [EMA]) as well as R/R CD33+ AML. The combination of venetoclax, an oral selective B-cell leukemia/lymphoma-2 inhibitor, with hypomethylating agents or low-dose AraC (LDAC) has changed the treatment landscape and prognosis for older adult patients very favorably. The addition of glasdegib, a small-molecule hedgehog inhibitor, to LDAC is another example of novel options in older patients. Further substances have shown promising results in early clinical trials.

Topics: Aged; Aminopyridines; Aniline Compounds; Antineoplastic Agents; Cytarabine; Daunorubicin; Drug Approval; Drug Discovery; Glycine; Humans; Leukemia, Myeloid, Acute; Male; Neoplasm Recurrence, Local; Pyrazines; Pyridines; Triazines

Mutations in IDH induce epigenetic and transcriptional reprogramming, differentiation bias, and susceptibility to mitochondrial inhibitors in cancer cells. Here, we first show that cell lines, PDXs, and patients with acute myeloid leukemia (AML) harboring an IDH mutation displayed an enhanced mitochondrial oxidative metabolism. Along with an increase in TCA cycle intermediates, this AML-specific metabolic behavior mechanistically occurred through the increase in electron transport chain complex I activity, mitochondrial respiration, and methylation-driven CEBPα-induced fatty acid β-oxidation of IDH1 mutant cells. While IDH1 mutant inhibitor reduced 2-HG oncometabolite and CEBPα methylation, it failed to reverse FAO and OxPHOS. These mitochondrial activities were maintained through the inhibition of Akt and enhanced activation of peroxisome proliferator-activated receptor-γ coactivator-1 PGC1α upon IDH1 mutant inhibitor. Accordingly, OxPHOS inhibitors improved anti-AML efficacy of IDH mutant inhibitors in vivo. This work provides a scientific rationale for combinatory mitochondrial-targeted therapies to treat IDH mutant AML patients, especially those unresponsive to or relapsing from IDH mutant inhibitors.

Topics: Acute Disease; Aminopyridines; Animals; Cell Line, Tumor; Doxycycline; Drug Resistance, Neoplasm; Enzyme Inhibitors; Epigenesis, Genetic; Glycine; HL-60 Cells; Humans; Isocitrate Dehydrogenase; Isoenzymes; Leukemia, Myeloid; Mice, Inbred NOD; Mice, Knockout; Mice, SCID; Mitochondria; Mutation; Oxadiazoles; Oxidative Phosphorylation; Piperidines; Pyridines; Triazines; Xenograft Model Antitumor Assays

Allosteric inhibitors of mutant IDH1 or IDH2 induce terminal differentiation of the mutant leukemic blasts and provide durable clinical responses in approximately 40% of acute myeloid leukemia (AML) patients with the mutations. However, primary resistance and acquired resistance to the drugs are major clinical issues. To understand the molecular underpinnings of clinical resistance to IDH inhibitors (IDHi), we perform multipronged genomic analyses (DNA sequencing, RNA sequencing and cytosine methylation profiling) in longitudinally collected specimens from 60 IDH1- or IDH2-mutant AML patients treated with the inhibitors. The analysis reveals that leukemia stemness is a major driver of primary resistance to IDHi, whereas selection of mutations in RUNX1/CEBPA or RAS-RTK pathway genes is the main driver of acquired resistance to IDHi, along with BCOR, homologous IDH gene, and TET2. These data suggest that targeting stemness and certain high-risk co-occurring mutations may overcome resistance to IDHi in AML.

Topics: Aged; Aminopyridines; Antineoplastic Agents; CCAAT-Enhancer-Binding Proteins; Core Binding Factor Alpha 2 Subunit; Dioxygenases; DNA Methylation; DNA-Binding Proteins; Drug Resistance, Neoplasm; Enzyme Inhibitors; Epigenomics; Evolution, Molecular; Female; Glycine; High-Throughput Nucleotide Sequencing; Humans; Isocitrate Dehydrogenase; Leukemia, Myeloid, Acute; Male; Middle Aged; Multigene Family; Neoplasm Recurrence, Local; Proto-Oncogene Proteins; Pyridines; ras Proteins; Repressor Proteins; RNA-Seq; Signal Transduction; Single-Cell Analysis; Stem Cells; Triazines

The acute myeloid leukemia (AML) treatment landscape has changed substantially since 2017. New targeted drugs have emerged, including venetoclax to target B-cell lymphoma 2, midostaurin and gilteritinib to target FLT3, and ivosidenib and enasidenib to target mutant isocitrate dehydrogenase 1 and 2, respectively. Other additions include reapproval of gemtuzumab ozogomycin to target CD33, glasdegib to target the hedgehog pathway, and a liposomal formulation of daunorubicin and cytarabine (CPX-351). Genomically heterogeneous AML has a tendency to evolve, particularly under selective treatment pressure. For decades, treatment decisions have largely centered around chemotherapy drug intensity. Physicians now have access to an increasing number of drugs with novel mechanisms of action and distinctive side-effect profiles. Key issues faced by hematologists in this era of new drugs include (1) the timely identification of actionable mutations at diagnosis and at relapse; (2) deciding which drug to use among several therapeutic options; and (3) increasing awareness of how to anticipate, mitigate, and manage common complications associated with these new agents. This article will use 3 case presentations to discuss some of the new treatment challenges encountered in AML management, with the goal of providing practical guidance to aid the practicing physician.

Topics: Adult; Aged; Aminopyridines; Aniline Compounds; Antineoplastic Agents; Biomarkers, Tumor; Bridged Bicyclo Compounds, Heterocyclic; Cytarabine; Daunorubicin; Female; fms-Like Tyrosine Kinase 3; Glycine; Humans; Isocitrate Dehydrogenase; Leukemia, Myeloid, Acute; Male; Molecular Targeted Therapy; Mutation; Prognosis; Pyrazines; Pyridines; Sialic Acid Binding Ig-like Lectin 3; Staurosporine; Sulfonamides; Triazines

Differentiation syndrome (DS) is a serious adverse reaction of isocitrate dehydrogenase (IDH) inhibitors ivosidenib and enasidenib in patients with. During FDA review of marketing applications for ivosidenib and enasidenib, data from pivotal trials were queried to identify cases of DS in patients with relapsed or refractory (R/R) AML. One hundred seventy-nine patients with R/R AML received ivosidenib and 214 received enasidenib. Adverse events, labs, and vital signs in the first 90 days of treatment were screened per diagnostic criteria, and narratives were reviewed to adjudicate DS cases.. We identified 72 of 179 (40%) potential cases for ivosidenib and 86 of 214 (40%) for enasidenib; 34 of 179 (19%) and 41 of 214 (19%) were adjudicated as DS. Leukocytosis was present in 79% and 61% of cases, respectively. Median (range) time to onset was 20 (1-78) and 19 (1-86) days. Grade ≥ 3 adverse reactions occurred in 68% and 66%; 6% and 5% were fatal. Univariate analyses suggested baseline bone marrow blasts ≥ 48% and peripheral blood blasts ≥ 25% and 15% for ivosidenib and enasidenib, respectively, were associated with increased risk of DS. Complete remission (CR) + CR with partial hematologic recovery rates were lower in patients with versus without DS [ivosidenib 18% (95% confidence interval, 7%-35%) vs. 36% (28%-45%); enasidenib 18% (7%-33%) vs. 25% (18%-32%)].. DS is a common and potentially fatal adverse reaction of IDH inhibitors, and use of standardized diagnostic criteria may aid in earlier diagnosis and treatment.

Topics: Aminopyridines; Glycine; Humans; Isocitrate Dehydrogenase; Leukemia, Myeloid, Acute; Mutation; Pyridines; Triazines; United States; United States Food and Drug Administration

Isocitrate dehydrogenase (IDH) inhibitors have clinical activity in acute myeloid leukemia, in part, by differentiating blasts to mature myeloid cells. In the largest systematic analysis to date, differentiation syndrome was seen in 19% of patients treated with IDH inhibitors. Early recognition with uniform diagnostic criteria, as utilized in acute promyelocytic leukemia, may reduce subsequent complications.

Topics: Aminopyridines; Cell Differentiation; Glycine; Humans; Isocitrate Dehydrogenase; Leukemia, Myeloid, Acute; Mutation; Pyridines; Triazines; United States; United States Food and Drug Administration

Topics: Acute Disease; Aminopyridines; Antineoplastic Agents; Antineoplastic Agents, Immunological; Congresses as Topic; Cytarabine; Daunorubicin; fms-Like Tyrosine Kinase 3; Gemtuzumab; Glycine; Humans; Leukemia; Pyridines; Recombinant Fusion Proteins; Staurosporine; Triazines