Genomic context and TP53 allele frequency define clinical outcomes in TP53-mutated myelodysplastic syndromes.

TP53 mutations are associated with adverse outcomes and shorter response to hypomethylating agents (HMAs) in myelodysplastic syndrome (MDS). Limited data have evaluated the impact of the type, number, and patterns of TP53 mutations in response outcomes and prognosis of MDS. We evaluated the clinicopathologic characteristics, outcomes, and response to therapy of 261 patients with MDS and TP53 mutations. Median age was 68 years (range, 18-80 years). A total of 217 patients (83%) had a complex karyotype. TP53 mutations were detected at a median variant allele frequency (VAF) of 0.39 (range, 0.01-0.94). TP53 deletion was associated with lower overall response rate (ORR) (odds ratio, 0.3; P = .021), and lower TP53 VAF correlated with higher ORR to HMAs. Increase in TP53 VAF at the time of transformation was observed in 13 patients (61%), and previously undetectable mutations were observed in 15 patients (65%). TP53 VAF was associated with worse prognosis (hazard ratio, 1.02 per 1% VAF increase; 95% confidence interval, 1.01-1.03; P < .001). Integration of TP53 VAF and karyotypic complexity identified prognostic subgroups within TP53-mutant MDS. We developed a multivariable model for overall survival that included the revised International Prognostic Scoring System (IPSS-R) categories and TP53 VAF. Total score for each patient was calculated as follows: VAF TP53 + 13 × IPSS-R blast score + 16 × IPSS-R cytogenetic score + 28 × IPSS-R hemoglobin score + 46 × IPSS-R platelet score. Use of this model identified 4 prognostic subgroups with median survival times of not reached, 42.2, 21.9, and 9.2 months. These data suggest that outcomes of patients with TP53-mutated MDS are heterogeneous and that transformation may be driven not only by TP53 but also by other factors.

NPM1 mutations define a specific subgroup of MDS and MDS/MPN patients with favorable outcomes with intensive chemotherapy.

Nucleophosmin (NPM1) mutations are common in acute myeloid leukemia and are associated with high remission rates and prolonged survival with intensive chemotherapy. NPM1 mutations are rare in myelodysplastic syndromes (MDS) or myelodysplastic/myeloproliferative neoplasm (MDS/MPN), and the clinical outcomes of these patients, when treated with intensive chemotherapy, are unknown. We retrospectively evaluated the clinicopathologic characteristics and the impact of therapy in 31 patients with MDS or MDS/MPN and NPM1 mutations. Next-generation sequencing was performed at diagnosis in 22 patients. Median age was 62 years (range, 19-86). Twenty-four patients (77%) had normal karyotype, and all had multilineage dysplasia. Most patients could be classified as MDS with excess blasts (19/31, 61%). NPM1 mutations were detected at a median allele frequency of 0.38 (range, 0.09-0.49). Mutation burden did not correlate with bone marrow blast frequency, and its clearance seemed to be associated with decreased morphologic dysplasia. Ten of the 31 patients (32%) received cytotoxic chemotherapy, 20 (65%) hypomethylating agents, and 1 (4%) lenalidomide. Sequential sequencing was available in 16 (52%) patients, and mutation burden correlated with disease status and response to therapy. Patients treated with chemotherapy had higher complete response rates (90% vs 28%, P = .004), longer median progression-free survival (not reached vs 7.5 months, P = .023), and overall survival (not reached vs 16 months, P = .047). Intensive chemotherapy and allogeneic stem cell transplantation (SCT) may be associated with improved clinical outcomes in patients with NPM1-mutated MDS or MDS/MPN who are candidates for this form of therapy.

Impact of the number of mutations in survival and response outcomes to hypomethylating agents in patients with myelodysplastic syndromes or myelodysplastic/myeloproliferative neoplasms.

The prognostic and predictive value of sequencing analysis in myelodysplastic syndromes (MDS) has not been fully integrated into clinical practice. We performed whole exome sequencing (WES) of bone marrow samples from 83 patients with MDS and 31 with MDS/MPN identifying 218 driver mutations in 31 genes in 98 (86%) patients. A total of 65 (57%) patients received therapy with hypomethylating agents. By univariate analysis, mutations in BCOR, STAG2, TP53 and SF3B1 significantly influenced survival. Increased number of mutations (≥ 3), but not clonal heterogeneity, predicted for shorter survival and LFS. Presence of 3 or more mutations also predicted for lower likelihood of response (26 vs 50%, p = 0.055), and shorter response duration (3.6 vs 26.5 months, p = 0.022). By multivariate analysis, TP53 mutations (HR 3.1, CI 1.3-7.5, p = 0.011) and number of mutations (≥ 3) (HR 2.5, CI 1.3-4.8, p = 0.005) predicted for shorter survival. A novel prognostic model integrating this mutation data with IPSS-R separated patients into three categories with median survival of not reached, 29 months and 12 months respectively (p < 0.001) and increased stratification potential, compared to IPSS-R, in patients with high/very-high IPSS-R. This model was validated in a separate cohort of 413 patients with untreated MDS. Although the use of WES did not provide significant more information than that obtained with targeted sequencing, our findings indicate that increased number of mutations is an independent prognostic factor in MDS and that mutation data can add value to clinical prognostic models.

Augmented Berlin-Frankfurt-Münster therapy in adolescents and young adults (AYAs) with acute lymphoblastic leukemia (ALL).

BACKGROUND: Various trials have reported improved outcomes for adolescents and young adults (AYAs) with acute lymphoblastic leukemia (ALL) who received treatment with pediatric-based regimens. Those reports prompted the current investigation of the pediatric augmented Berlin-Frankfurt-Münster (ABFM) regimen in AYA patients. The results were compared with those from a similar population that received the hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone (hyper-CVAD) regimen. METHODS: Eighty-five patients ages 12 to 40 years who had Philadelphia chromosome (Ph)-negative ALL received the ABFM regimen from October 2006 through April 2012. Their outcome was compared with outcomes in 71 historic AYA patients who received hyper-CVAD from the authors' institution. Patient and disease characteristics, as well as minimal residual disease status, were analyzed for their impact on outcomes. RESULTS: The complete response rate with ABFM was 94%. The 3-year complete remission duration (CRD) and overall survival (OS) rates were 70% and 74%, respectively. For patients aged ≤21 years, the 3-year CRD and OS rates were 72% and 85%, respectively; and, for patients ages 21 to 40 years, the respective rates were 69% and 60%. The initial white blood cell count was an independent predictive factor of OS and CRD. The minimal residual disease status on days 29 and 84 of therapy also were predictive of long-term outcomes. Severe regimen toxicities included transient hepatotoxicity in 35% to 39% of patients, pancreatitis in 11% of patients, osteonecrosis in 11% of patients, and thrombosis in 22% of patients. The 3-year OS rate was 74% in the ABFM group versus 71% in the hyper-CVAD group, and the corresponding 3-year CRD rate was 70% versus 66%, respectively. CONCLUSIONS: ABFM was tolerable in AYA patients with ALL but was not associated with significant improvements in CRD and OS compared with hyper-CVAD.

A phase I and pharmacodynamic study of AT9283, a small-molecule inhibitor of aurora kinases in patients with relapsed/refractory leukemia or myelofibrosis.

BACKGROUND: This study sought to identify the maximum tolerated dose (MTD) of AT9283, an inhibitor of Aurora kinases A and B, in patients with relapsed or refractory leukemias. Other endpoints included pharmacokinetics, safety and tolerability, pharmacodynamics, and preliminary evidence of efficacy. PATIENTS AND METHODS: AT9283 was administered as a continuous 72-hour infusion every 21 days. Doses were escalated by a standard 3 + 3 design. After the MTD for the 72-hour infusion was identified, infusion duration was increased incrementally to 96 hours and 120 hours. In total, 48 patients received ≥ 1 cycle of AT9283. Median age was 61 years (range, 22-86 years); 56% were men; 75% were diagnosed with AML; and 89% had received ≥ 3 (up to 16) prior lines of therapy. RESULTS: 324 mg/m(2)/72 h AT9283 was determined to be the MTD. Dose-limiting toxicities (DLTs) were myocardial infarction, hypertension, cardiomyopathy, tumor lysis syndrome, pneumonia, and multiorgan failure. Other AT9283-related toxicities (non-DLT) included myelosuppression, predominantly leukopenia and mucositis. Bone marrow blasts decreased ≥ 38% after AT9283 treatment in approximately one-third of patients with relapsed/refractory AML; however, this effect was transient and no objective responses were achieved, despite evidence of Aurora kinase B inhibition. Two patients with accelerated-phase chronic myeloid leukemia showed evidence of benefit, manifested as a cytogenetic response in 1 case; 1 patient completed 6 cycles of treatment. Exposure to AT9283 was generally dose proportional. CONCLUSION: AT9283 tolerability was strongly dose-dependent, with reversible myelosuppression predominating at lower doses and events such as cardiovascular toxicities manifesting at higher doses. Clinical trials with AT9283 are ongoing in alternative patient populations.

Red blood cell-encapsulated L-asparaginase: potential therapy of patients with asparagine synthetase deficient acute myeloid leukemia.

Red blood cell (RBC) encapsulated L-asparaginase is a novel therapeutic for the treatment of asparagine auxotrophic malignancies. The enzyme-loaded red blood cells function as bioreactors to deplete bloodstream substrate. This delivery system provides improved pharmacodynamics with protection from circulating proteolytic enzymes and avoidance of early liver or renal clearance. The "drug" is manufactured with ABO and Rh compatible donor blood when a prescription is received. Because of the industrial scale manufacturing, the "drug" is transfused the day of receipt at the clinical site. Preliminary clinical studies show utility in childhood and adult acute lymphoblastic leukemia. Based on previous studies of applications in different diseases and assessment of different biomarkers, we propose this agent offers a safe and potentially effective treatment for a subset of chemotherapy refractory acute myeloid leukemia patients. The history, chemistry, biology, pharmacology, and relevant clinical experiences with L-asparaginase as well as the properties and proposed protocols with the red cell-encapsulated enzyme are reviewed.

Long-term outcomes of 107 patients with myelofibrosis receiving JAK1/JAK2 inhibitor ruxolitinib: survival advantage in comparison to matched historical controls.

Ruxolitinib is JAK1/JAK2 inhibitor with established clinical benefit in myelofibrosis (MF). We analyzed long-term outcomes of 107 patients with intermediate-2 or high-risk MF receiving ruxolitinib at MD Anderson Cancer Center (MDACC) on phase 1/2 trial. After a median of 32 months of follow-up, 58 patients (54%) were still receiving ruxolitinib, with overall survival (OS) of 69%. The splenomegaly and symptom reductions achieved with ruxolitinib were sustained with long-term therapy. Therapy was well tolerated; discontinuation rates at 1, 2, and 3 years were 24%, 36%, and 46%, respectively. OS of 107 MDACC patients was significantly better (P = .005) than that of 310 matched (based on trial enrollment criteria) historical control patients, primarily because of highly significant difference in OS in the high-risk subgroup (P = .006). Furthermore, among MDACC patients, those with high-risk MF experienced the same OS as those with intermediate-2 risk. Patients with ≥ 50% reduction in splenomegaly had significantly prolonged survival versus those with < 25% reduction (P < .0001). Comparison of discontinuation rates and reasons for stopping the therapy to those reported for other 51 patients in the phase 1/2 trial, and 155 ruxolitinib-treated patients in phase 3 COMFORT-I study, suggest that continued therapy with ruxolitinib at optimal doses contributes to the benefits seen, including OS benefit.

Addition of AEG35156 XIAP antisense oligonucleotide in reinduction chemotherapy does not improve remission rates in patients with primary refractory acute myeloid leukemia in a randomized phase II study.

BACKGROUND: XIAP (X-linked inhibitor of apoptosis protein) is an inhibitor of caspases 3 and 9 that is overexpressed in acute myeloid leukemia (AML) and may contribute to chemoresistance. We report an open-label randomized phase II trial of reinduction chemotherapy with and without the XIAP antisense oligonucleotide AEG35156 in patients with AML who did not achieve remission with initial induction chemotherapy. METHODS: Twenty-seven patients with AML who were refractory to initial induction chemotherapy were randomized and treated with AEG35156 (650 mg) in combination with high-dose cytarabine and idarubicin. Thirteen patients were randomized and treated with high-dose cytarabine and idarubicin alone. The rates of response and toxicity were determined. RESULTS: Of the 27 patients assigned to AEG35156 in combination with high-dose cytarabine and idarubicin, 3 died during reinduction chemotherapy, 5 achieved complete remission (CR), and 6 achieved CR with incomplete platelet count recovery (CRp), for an overall response rate of 41%. Of the 13 patients assigned to the control arm of the study, none died during reinduction, 6 achieved CR, and 3 achieved CRp, for an overall response rate of 69%. The differences in response rates between patients in the AEG35156 and control arms were not statistically different (P = 0.18 by the χ(2) test). CONCLUSIONS: The addition of AEG35156 to reinduction chemotherapy was well tolerated but did not improve rates of remission. Therefore alternative therapeutic strategies should be explored in patients with AML refractory to induction chemotherapy.

Pleural effusion in patients with chronic myelogenous leukemia treated with dasatinib after imatinib failure.

PURPOSE: We investigated the risk factors and management of pleural effusion associated with dasatinib therapy for chronic myelogenous leukemia (CML) after failure of imatinib. PATIENTS AND METHODS: We analyzed 138 patients with CML treated with dasatinib from November 2003 to January 2006 in one phase I (n = 50) and four phase II (n = 88) studies for the development of pleural effusion. RESULTS: Pleural effusion occurred in 48 patients (35%; grade 3/4 in 23 [17%]), including 29% of those treated in chronic phase (CP), 50% in accelerated phase (AP), and 33% in blast phase (BP). By multivariate analysis, history of cardiac disease, hypertension, and use of a twice-daily schedule (v once daily) were identified as factors associated with development of pleural effusions. Effusions were exudative in 78% of the assessable cases. In some patients, effusions were associated with reversible increments of right ventricular systolic pressure. Management included transient dasatinib interruption in 83%, diuretics in 71%, pulse steroids in 27%, and thoracentesis in 19% of patients. CONCLUSION: Pleural effusions occur during dasatinib therapy, particularly among patients in AP or BP. A twice-daily schedule may result in a higher incidence of pleural effusion. Close monitoring and timely intervention may allow patients to continue therapy and achieve the desired clinical benefit.