Efficacy of the hypomethylating agents as frontline, salvage, or consolidation therapy in adults with acute myeloid leukemia (AML)

The hypomethylating agents (HAs), azacitidine and decitabine, have emerged as an alternative to initial and salvage therapy in patients with acute myeloid leukemia (AML). Little is known about how AML responds to hypomethylating agents after standard therapy, and the activity of these agents in a real-world setting is not well studied. We retrospectively examined data for 75 consecutive AML patients at Wake Forest from 2002 to 2011 treated with HAs either as first-line (n?=?34), salvage (n?=?28), or consolidation (n?=?13) therapy. We collected data on age, gender, race, Charlson comorbidity index (CCI), cytogenetics, type of treatment, complete remission (CR), complete remission with incomplete count recovery (CRi), and survival. Statistical analysis was performed using Kaplan–Meier estimates and Cox proportional hazards models. Frontline response rate (CR + CRi) was 26.5 %, and median overall survival (OS) was 3.4 months (95 % CI 1.3–7.4), with 18 % alive at 1 year. In the salvage cohort, the response rate was significantly lower compared to frontline (3.6 versus 26.5 %, p?=?0.017). Despite the reduced response, OS from time of HA treatment was longer than frontline at 8.2 months (CI 4.8–10.3). In the consolidation cohort, OS was 13.8 months (CI 8.0–21.6) with one patient in remission more than 30 months from diagnosis. These data suggest that prior cytotoxic therapy decreases marrow response rates to HAs but not survival. Furthermore, use of hypomethylating agents for consolidation resulted in a median overall survival over 1 year in a cohort of older patients. This suggests that hypomethylating agents have activity in all phases of AML treatment.     

Therapeutic decision-making in elderly patients with acute myeloid leukemia: conventional intensive chemotherapy versus hypomethylating agent therapy

Standards of care for elderly acute myeloid leukemia (AML) patients unfit for intensive chemotherapy remain undefined. We aimed to compare outcomes of hypomethylating agent (HMA) therapy and intensive chemotherapy (IC) in elderly AML patients and identify the subgroup of patients who are eligible for HMA therapy. We reviewed data on the outcomes of 86 AML patients aged ≥ 65 years, who had undergone treatment between 2010 and 2015. These treatments included IC (25 patients, 29.1%) or therapy using HMA including azacitidine or decitabine (61 patients, 70.9%). The overall response rates were 32 and 19.7%, respectively. Median overall survival (OS) (8 vs. 8 months) and progression-free survival (PFS) (6 vs. 7 months) durations were similar in the two groups. Patients in the HMA group with less than 10% peripheral blood (PB) blasts achieved significantly better OS duration than patients in the IC group (P = 0.043). Patients in the IC group with PB blasts and bone marrow blast of ≥ 10 and ≥ 50%, respectively, achieved better PFS durations than the corresponding patients in the HMA group (P = 0.038). Multivariate analysis identified the hematologic improvement-platelet (HI-P) as an independent prognostic factor for survival in the HMA group (P = 0.005). Our results showed that HMA therapy and IC were associated with similar survival duration in elderly AML patients. This study was noteworthy because it assessed prognostic factors that would help to select elderly patients who could expect actual benefits from undergoing the different therapeutic options available, especially HMA therapy.     

Venetoclax and hypomethylating agents in acute myeloid leukemia: Mayo Clinic series on 86 patients

Venetoclax and hypomethylating agent (HMA) combination therapy is FDA-approved for elderly or unfit acute myeloid leukemia (AML) patients unable to withstand intensive chemotherapy. The primary objective of the current study was to impart our institutional experience with the above regimen, outlining response, survival outcomes, and its determinants amongst 86 treatment- naïve and relapsed/refractory AML patients. A total of 44 treatment-naïve AML patients, median age 73.5 years, enriched with secondary, therapy related and ELN adverse risk disease (n = 27) were studied. The CR/CRi rates of 50% (22 of 44 patients) were superior to 23% in a matched AML cohort treated with HMA alone (P = .005). Response rates were similar with TP53, FLT3, NPM1 and IDH mutations (P = .31). Moreover, CEPBA mutations (P = .03) and neutropenia (P = .05) emerged as predictors of complete response. Survivalwas prolonged in patients achieving CR/CRi (17 vs 3 months without CR/CRi, P < .001; conversely adverse ELN risk portended inferior survival. Amongst 42 relapsed/refractory AML patients, half received ≥2 prior therapies excluding transplant, and 15 (35.7%) had received HMA. A group of 14 patients (33.3%) attained CR/CRi; age > 65 years, AML with myelodysplasia, JAK2, DNMT3A, and BCOR mutations predicted complete response. Survival distinctions were based on CR/CRi (median survival 15 vs 3 months with/without CR/CRi; P < .001), and TP53 mutation status (P = .04). In summary, we corroborate existing reports demonstrating superior response and prolonged survival with venetoclax and HMA in treatment -naïve and relapsed/refractory AML patients regardless of genotype. Additionally, we identify unique predictors of response to therapy which require validation.     

Induction therapy for elderly patients with acute myeloid leukemia

Acute myeloid leukemia (AML) is a disease of older adults. Efforts to intensify therapy along traditional avenues have failed to yield improved results. There remains significant clinical equipoise as to how to “induce” patients and whether or not 7 + 3-style regimens improve outcomes over low-dose cytarabine. What is certain is that even in those not receiving active therapy, AML is an exceptionally morbid disease. Diverse interventions are being explored in the management of older patients with AML and the currently available data will be reviewed.     

Predictors of clinical responses to hypomethylating agents in acute myeloid leukemia or myelodysplastic syndromes

Azacitidine and decitabine, two hypomethylating agents, are known to be effective in the treatment of high-risk myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML) patients who cannot endure intensive cytotoxic chemotherapy or are not eligible for transplantation. However, the treatment response rate is low. The molecular mechanisms underlying the resistance to demethylation therapy are unclear. Though a wide range of predictors of treatment response have been investigated, no consensus has been reached. It is imperative to identify certain parameters that can help distinguish between patients who will obtain a favorable outcome from demethylation therapy and those who will not. Here, we describe currently researched potential predictors based on clinical characteristics, DNA methylation, gene mutation, gene expression, microRNAs, and protein expression. Although these parameters are not currently used in clinical practice, this review provides new sights into available clinical and experimental research. Moreover, this paper provides useful information on AML/MDS management.     

Presence of isocitrate dehydrogenase mutations may predict clinical response to hypomethylating agents in patients with acute myeloid leukemia

Mutations in IDH1 and IDH2 occur in 15–20% of AML cases, resulting in the production of 2‐hydroxyglutarate, which promotes aberrant hypermethylation of DNA in leukemic cells. Although these mutations have been shown to have prognostic implications for patients with AML, optimal treatment strategies have yet to be defined. We retrospectively identified forty‐two patients with AML treated with DNA methyltransferase inhibitors (DNMTIs) decitabine (n = 36) or azacitidine (n = 6) and performed analysis of stored samples for the presence of IDH1 and IDH2 mutations. Of the forty‐two samples analyzed, seven (16.7%) had IDH mutations. Thirteen patients (31%) achieved remission [(complete remission (CR)/complete remission with incomplete count recovery (CRi)/partial response (PR)] after treatment with a DNMTI, five of seven (71.4%) with IDH mutations and eight of thirty‐five (22.9%) without IDH mutations (P = 0.01). When adjusted for age at diagnosis, sex, bone marrow blast percentage and cytogenetic, the odds of achieving response after administration of a DNMTI among patients with an IDH mutation was 14.2 when compared to patients without an IDH mutation (95%CI: 1.3–150.4). IDH1 and IDH2 mutations may predict a favorable response to DNMTI in patients with AML. Am. J. Hematol. 90:E77–E79, 2015. © 2015 Wiley Periodicals, Inc.     

Nilotinib as frontline and second-line therapy in chronic myeloid leukemia: open questions

Nilotinib is a second generation ABL tyrosine kinase inhibitor (TKI) that exerts major anti-leukemic effects in newly diagnosed patients with chronic myeloid leukemia (CML) as well as in most patients with imatinib-resistant CML. In freshly diagnosed patients, the anti-leukemic activity of nilotinib exceeds the efficacy of imatinib, and although long-term data for nilotinib are not available yet, the drug has recently been approved for firstline treatment of chronic phase CML in various countries. Still however, several questions concerning the optimal dose, follow-up parameters, long-term safety, and patient selection remain open. Likewise, it remains uncertain whether both Sokal low-risk and high-risk patients should receive nilotinib as frontline therapy in the future. Another question is whether nilotinib can completely eradicate CML in a subset of patients. Furthermore, it remains unclear whether and what comorbidity must be regarded as relative or absolute contra-indication for this TKI. To discuss these issues, the Austrian CML Working Group organized a series of meetings in 2010. In the current article, the outcomes from these discussions are summarized and presented together with recommendations for frontline use of TKIs in various groups of patients with CML. These recommendations should assist in daily practice as well as in the preparation and conduct of clinical trials.     

Tailored temozolomide therapy according to MGMT methylation status for elderly patients with acute myeloid leukemia

Temozolomide sensitivity is determined by methylation of the O(6)-methylguanine-DNA methyltransferase (MGMT) promoter. This study assessed whether the temozolomide dose can be tailored by MGMT promoter status and whether protracted, low-dose temozolomide can "prime" blasts in patients with unmethylated MGMT (unMGMT). Elderly patients with high-risk AML were stratified by MGMT methylation. Patients with methylated MGMT (mMGMT) received temozolomide 200 mg/m(2) orally for 7 days every 4 weeks, while patients with unMGMT received temozolomide 100 mg/m(2) orally for 14 days followed by 200 mg/m(2) orally for 7 days every 6weeks. Of 36 patients (median age, 75 years), 31 (86%) had an unMGMT promoter. Overall response rate for the entire cohort was 36%. Patients with mMGMT and unMGMT had similar response rates (40% vs. 29%). Median duration of response and overall survival (OS) among responders were 29 and 35 weeks, respectively. Induction deaths (ID) occurred in 25% of patients, mostly caused by disease progression. Hematological toxicities were the most common adverse event. Toxicities were similar between patients on conventional versus protracted schedules. High HCT-CI scores were predictive of lower CR rate, higher ID, and shorter OS, while bone marrow blast count <50% at screening predicted for improved responses. Temozolomide, dosed according to MGMT methylation status, demonstrated modest clinical activity in elderly patients with AML, especially in those presenting with fewer comorbidities and low disease burden. The trial was registered on www.ClinicalTrials.gov as #NCT00611247.     

Venetoclax + hypomethylating agents combined with dose-adjusted HAG for relapsed/refractory acute myeloid leukemia: Two case reports

Rationale:Some acute myeloid leukemia (AML) patients are unresponsive to treatment or have remission followed by worsening of disease (known as relapsed/refractory AML [R/RAML]) after standardized treatment. The CAG/HAG regimen is not often used clinically because heterogenous patient responses, resistance, and hematopoietic bone marrow dysfunction have been reported with its use. We present 2 cases of R/RAML treated with a new combined therapy (venetoclax+ hypomethylating agents [HMAs]) in which the HAG dose was adjusted and effective in the first course of treatment.Patient characteristics:Case 1 involved a 23-year-old man who had suffered from AML for >4 years, and his FLT3 mutation status was positive at the initial diagnosis. After the first course of treatment with the standard-dose “Da” plan, the patient experienced complete remission. During the subsequent courses of treatment, the patient experienced 6 recurrences and was treated with the “ID Ara-C + MIT + sidaaniline” and “CAG + sidaaniline” regimens. However, the disease did not respond. Case 2 involved a 26-year-old man who received chemotherapy with the “Da,” “ID Ara-C,” “decitabine + half-dose CAG,” and “HAE” regimens. In this patients, remission could not be achieved. Reintroduction of the “ia” scheme also failed after treatment in our hospital.Diagnosis:Two patients were diagnosed with R/RAML.Interventions:The patient in case 2 received chemotherapy interventions, whereas the patient in case 1 refused to receive medical services at our hospital.Outcomes:The patient in case 1 was discharged after complete response treatment due to economic reasons and relapsed 2 months later. The patient ultimately died of infection and heart failure. The patient in case 2 is receiving a second cycle of chemotherapy.Lessons:We recommend the “venetoclax + HMAs combined with dose-adjusted CAH/HAG” regimen as an effective treatment for adult R/RAML.     

Clinical outcome after failure of hypomethylating therapy for myelodysplastic syndrome

Around half of patients with myelodysplastic syndrome (MDS) fail to respond to hypomethylating therapy (HMT) and most responders progress within 2 yr. Retrospective studies report poor outcomes after HMT failure. Here, we analyzed the outcomes of patients suffering HMT failure. Of 149 patients with MDS treated with either azacitidine or decitabine, 91 who experienced HMT failure were included in the study. Median overall survival (OS) was 12.1 months: 16.2 months for lower‐risk MDS and 9.3 months for higher‐risk MDS. Disease status and progression to acute myeloid leukemia (AML) at the time of HMT failure were independent prognostic factors for OS. Fifty‐four patients received one or more treatment modalities, and 23 received allogeneic hematopoietic cell transplantation (HCT). The objective response to non‐transplant treatments was poor (11–17%), whereas 17 transplanted patients showed a complete response. OS probability at 2 yr post‐HCT was 60.9%: 78.6% for patients receiving HCT during MDS and 33.3% for those receiving HCT after developing AML. In conclusion, the clinical outcome of patients after HMT failure was poor. Long‐term disease‐free survival was observed in approximately 50% of patients who received allogeneic HCT. Therefore, allogeneic HCT should be performed early in appropriate patients, and particularly before progression to AML.     

A phase II study of omacetaxine mepesuccinate for patients with higher-risk myelodysplastic syndrome and chronic myelomonocytic leukemia after failure of hypomethylating agents

The outcome of patients with myelodysplastic syndromes (MDSs) after failure of hypomethylating agents (HMAs) failure is poor with a median overall survival (OS) of only 4-6 months. Omacetaxine mepesuccinate (OM) is safe and effective in myeloid malignancies but has not been studied in MDS with HMA failure. We conducted a phase II study of OM in patients with MDS or chronic myelomonocytic leukemia (CMML) who had previously failed or been intolerant to HMAs. Patients received OM at a dose of 1.25 mg/m² subcutaneously every 12 hours for 3 consecutive days on a 4- to 7-week schedule. The primary endpoints were the overall response rate (ORR) and OS. A total of 42 patients were enrolled with a median age of 76 years. The ORR was 33%. Patients with diploid cytogenetics were more likely to respond to OM than were those with cytogenetic abnormalities (58% vs 23%, respectively; P = .03). Overall, the median OS was 7.5 months and 1-year OS rate was 25%. Patients with diploid cytogenetics had superior OS to those with cytogenetic abnormalities (median OS 14.8 vs 6.8 months, respectively; P = .01). Two patients had ongoing response to OM of 2 years or longer (both MDS with diploid cytogenetics and RUNX1 mutation). The most common grade ≥ 3 adverse events were infections in 11 patients (26%), febrile neutropenia in 4 (10%), and hemorrhage in 3 (7%). Overall, OM was safe and active in patients with MDS or CMML who experienced HMA failure. These results support the further development of OM in this setting.