Early epigenetic changes and DNA damage do not predict clinical response in an overlapping schedule of 5-azacytidine and entinostat in patients with myeloid malignancies.

Sequential administration of DNA methyltransferase (DNMT) inhibitors and histone deacetylase (HDAC) inhibitors has demonstrated clinical efficacy in patients with hematologic malignancies. However, the mechanism behind their clinical efficacy remains controversial. In this study, the methylation dynamics of 4 TSGs (p15(INK4B), CDH-1, DAPK-1, and SOCS-1) were studied in sequential bone marrow samples from 30 patients with myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML) who completed a minimum of 4 cycles of therapy with 5-azacytidine and entinostat. Reversal of promoter methylation after therapy was observed in both clinical responders and nonresponders across all genes. There was no association between clinical response and either baseline methylation or methylation reversal in the bone marrow or purified CD34(+) population, nor was there an association with change in gene expression. Transient global hypomethylation was observed in samples after treatment but was not associated with clinical response. Induction of histone H3/H4 acetylation and the DNA damage-associated variant histone gamma-H2AX was observed in peripheral blood samples across all dose cohorts. In conclusion, methylation reversal of candidate TSGs during cycle 1 of therapy was not predictive of clinical response to combination "epigenetic" therapy. This trial is registered with http://www.clinicaltrials.gov under NCT00101179.

A phase 1/2 study of rigosertib in patients with myelodysplastic syndromes (MDS) and MDS progressed to acute myeloid leukemia.

This Phase 1/2, dose-escalating study of rigosertib enrolled 22 patients with higher-risk myelodysplastic syndromes (MDS) (n=9) and acute myeloid leukemia (AML; n=13) who had relapsed or were refractory to standard therapy and for whom no second-line therapies were approved. Patients received 3- to 7-day continuous intravenous infusions of rigosertib, an inhibitor of Ras-effector pathways that interacts with the Ras-binding domains, common to several signaling proteins including Raf and PI3 kinase. Rigosertib was administered at doses of 650-1700mg/m2/day in 14-day cycles. Initial dose escalation followed a Fibonacci scheme, followed by recommended phase 2 dose confirmation in an expanded cohort. Rigosertib was well tolerated for up to 23 cycles, with no treatment-related deaths and 18% of patients with related serious adverse events (AEs). Common AEs were fatigue, diarrhea, pyrexia, dyspnea, insomnia, and anemia. Rigosertib exhibited biologic activity, with reduction or stabilization of bone marrow blasts and improved peripheral blood counts in a subset of patients. Ten of 19 evaluable patients (53%) demonstrated bone marrow/peripheral blood responses (n=4 MDS, n=1 AML) or stable disease (n=3 MDS, n=2 AML). Median survival was 15.7 and 2.0 months for responders and non-responders, respectively. Additional studies of rigosertib are ongoing in higher-risk MDS (NCT00854646).

Impact of azacytidine on the quality of life of patients with myelodysplastic syndrome treated in a randomized phase III trial: a Cancer and Leukemia Group B study.

PURPOSE: The impact of azacytidine (Aza C) on the quality of life of 191 patients with myelodysplastic syndrome was assessed in a phase III Cancer and Leukemia Group B trial (9221). PATIENTS AND METHODS: One hundred ninety-one patients (mean age, 67.5 years; 69% male) were randomized to receive either Aza C (75 mg/m(2) subcutaneous for 7 days every 4 weeks) or supportive care, with supportive care patients crossing over to Aza C upon disease progression. Quality of life was assessed by centrally conducted telephone interviews at baseline and days 50, 106, and 182. Overall quality of life, psychological state, and social functioning were assessed by the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire C30 and the Mental Health Inventory (MHI). RESULTS: Patients on the Aza C arm experienced significantly greater improvement in fatigue (EORTC, P =.001), dyspnea (EORTC, P =.0014), physical functioning (EORTC, P =.0002), positive affect (MHI, P =.0077), and psychological distress (MHI, P =.015) over the course of the study period than those in the supportive care arm. Particularly striking were improvements in fatigue and psychological state (MHI) in patients treated with Aza C compared with those receiving supportive care for patients who remained on study through at least day 106, corresponding to four cycles of Aza C. Significant differences between the two groups in quality of life were maintained even after controlling for the number of RBC transfusions. CONCLUSION: Improved quality of life for patients treated with Aza C coupled with significantly greater treatment response and delayed time to transformation to acute myeloid leukemia or death compared with patients on supportive care (P <.001) establishes Aza C as an important treatment option for myelodysplastic syndrome.

Randomized controlled trial of azacitidine in patients with the myelodysplastic syndrome: a study of the cancer and leukemia group B.

PURPOSE: Patients with high-risk myelodysplastic syndrome (MDS) have high mortality from bone marrow failure or transformation to acute leukemia. Supportive care is standard therapy. We previously reported that azacitidine (Aza C) was active in patients with high-risk MDS. PATIENTS AND METHODS: A randomized controlled trial was undertaken in 191 patients with MDS to compare Aza C (75 mg/m(2)/d subcutaneously for 7 days every 28 days) with supportive care. MDS was defined by French-American-British criteria. New rigorous response criteria were applied. Both arms received transfusions and antibiotics as required. Patients in the supportive care arm whose disease worsened were permitted to cross over to Aza C. RESULTS: Responses occurred in 60% of patients on the Aza C arm (7% complete response, 16% partial response, 37% improved) compared with 5% (improved) receiving supportive care (P <.001). Median time to leukemic transformation or death was 21 months for Aza C versus 13 months for supportive care (P =.007). Transformation to acute myelogenous leukemia occurred as the first event in 15% of patients on the Aza C arm and in 38% receiving supportive care (P =.001). Eliminating the confounding effect of early cross-over to Aza C, a landmark analysis after 6 months showed median survival of an additional 18 months for Aza C and 11 months for supportive care (P =.03). Quality-of-life assessment found significant major advantages in physical function, symptoms, and psychological state for patients initially randomized to Aza C. CONCLUSION: Aza C treatment results in significantly higher response rates, improved quality of life, reduced risk of leukemic transformation, and improved survival compared with supportive care. Aza C provides a new treatment option that is superior to supportive care for patients with the MDS subtypes and specific entry criteria treated in this study.