The development of effective treatment strategies for most forms of acute myeloid leukemia (AML) has languished for the past several decades. There are a number of reasons for this, but key among them is the considerable heterogeneity of this disease and the paucity of molecular markers that can be used to predict clinical outcomes and responsiveness to different therapies. The recent large-scale sequencing of AML genomes is now providing opportunities for patient stratification and personalized approaches to treatment that are based on individual mutational profiles. It is particularly notable that studies by The Cancer Genome Atlas and others have determined that 44% of patients with AML exhibit mutations in genes that regulate methylation of genomic DNA. In particular, frequent mutation has been observed in the genes encoding DNA methyltransferase 3A (DNMT3A), isocitrate dehydrogenase 1 (IDH1) and isocitrate dehydrogenase 2 (IDH2), as well as Tet oncogene family member 2. This review will summarize the incidence of these mutations, their impact on biochemical functions including epigenetic modification of genomic DNA and their potential usefulness as prognostic indicators. Importantly, the presence of DNMT3A, IDH1 or IDH2 mutations may confer sensitivity to novel therapeutic approaches, including the use of demethylating agents. Therefore, the clinical experience with decitabine and azacitidine in the treatment of patients harboring these mutations will be reviewed. Overall, we propose that understanding the role of these mutations in AML biology will lead to more rational therapeutic approaches targeting molecularly defined subtypes of the disease.

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Belumosudil, an investigational oral selective inhibitor of rho-associated coiled-coil-containing protein kinase-2 (ROCK2), reduces type 17 and follicular helper T cells via downregulation of signal transducer and activator of transcription 3 (STAT3) and enhances regulatory T cells via upregulation of signal transducer and activator of transcription 5 (STAT5). Belumosudil may effectively treat patients with cGVHD, a major cause of morbidity and late nonrelapse mortality after an allogeneic hematopoietic cell transplant. This phase 2, randomized, multicenter registration study evaluated belumosudil 200 mg QD (n=66) and 200 mg BID (n=66) in subjects with cGVHD who had received 2 to 5 prior lines of therapy. The primary end point was best overall response rate (ORR). Duration of response (DOR), changes in Lee Symptom Scale score, failure-free survival, corticosteroid dose reductions and overall survival were also evaluated. Overall median follow-up was 14 months. The best ORR (95% CI) of belumosudil 200 mg QD and 200 mg BID was 74% (62%-84%) and 77% (65%-87%), respectively, with high response rates observed in all subgroups. All affected organs demonstrated complete responses. The median DOR was 54 weeks; 44% of subjects have remained on therapy for ≥1 year. Symptom reduction with belumosudil 200 mg QD and 200 mg BID was reported in 59% and 62% of subjects, respectively. Adverse events (AEs) were consistent with those expected in patients with cGVHD receiving corticosteroids and other immunosuppressants. Sixteen subjects (12%) discontinued belumosudil due to possible drug-related AEs. Belumosudil, a promising therapy for cGVHD, was well tolerated with clinically meaningful responses. (Funded by Kadmon Corporation, LLC; ClinicalTrials.gov number, NCT03640481.)

The field of immunotherapy in cancer treatments has been accelerating over recent years and has entered the forefront as a leading area of ongoing research and promising therapies that have changed the treatment landscape for a variety of solid malignancies. Prior to its designation as the Science Breakthrough of the Year in 2013, cancer immunotherapy was active in the treatment of hematologic malignancies. This review provides a broad overview of the past, present, and potential future of immunotherapy in hematologic malignancies.