Epigenetic therapy with hypomethylating drugs is now the standard of care in myelodysplastic syndrome (MDS). Response rates remain low, and mechanismbased dose optimization has not been reported. We investigated the clinical and pharmacodynamic results of different dose schedules of decitabine. Adults with advanced MDS or chronic myelomonocytic leukemia (CMML) were randomized to 1 of 3 decitabine schedules: (1) 20 mg/m 2 intravenously daily for 5 days; (2) 20 mg/m 2 subcutaneously daily for 5 days; and (3) 10 mg/m 2 intravenously daily for 10 days. Randomization followed a Bayesian adaptive design. Ninety-five patients were treated (77 with MDS, and 18 with CMML). Overall, 32 patients (34%) achieved a complete response (CR), and 69 (73%) had an objective response by the new modified International Working Group criteria. The 5-day intravenous schedule, which had the highest doseintensity, was selected as optimal; the CR rate in that arm was 39%, compared with 21% in the 5-day subcutaneous arm and 24% in the 10-day intravenous arm (P < .05). The high dose-intensity arm was also superior at inducing hypomethylation at day 5 and at activating P15 expression at days 12 or 28 after therapy. We conclude that a low-dose, doseintensity schedule of decitabine optimizes epigenetic modulation and clinical responses in MDS. (Blood. 2007;109: 52-57)

There has been an increasing interest in the analysis of recurrent event data (Cook and Lawless, 2002, Statistical Methods in Medical Research 11, 141-166). In many situations, a terminating event such as death can happen during the follow-up period to preclude further occurrence of the recurrent events. Furthermore, the death time may be dependent on the recurrent event history. In this article we consider frailty proportional hazards models for the recurrent and terminal event processes. The dependence is modeled by conditioning on a shared frailty that is included in both hazard functions. Covariate effects can be taken into account in the model as well. Maximum likelihood estimation and inference are carried out through a Monte Carlo EM algorithm with Metropolis-Hastings sampler in the E-step. An analysis of hospitalization and death data for waitlisted dialysis patients is presented to illustrate the proposed methods. Methods to check the validity of the proposed model are also demonstrated. This model avoids the difficulties encountered in alternative approaches which attempt to specify a dependent joint distribution with marginal proportional hazards and yields an estimate of the degree of dependence.

Summary Background Ibrutinib, an orally administered covalent inhibitor of Bruton tyrosine kinase (BTK), is an effective therapy for patients with relapsed chronic lymphocytic leukemia (CLL). We investigated the activity and safety of the combination of ibrutinib with the monoclonal antibody rituximab (iR) in patients with high-risk CLL. Methods In this single-arm, phase 2 studywe enrolled 40 patients with high-risk CLL at MD Anderson Cancer Center, Houston, Texas, USA. Patients with symptomatic CLL requiring therapy received 28 day cycles of once-daily ibrutinib 420 mg , together with rituximab (weekly during cycle 1, then once per cycle until cycle 6), followed by continuous single-agent ibrutinib. The primary endpoint was progression-free survival (PFS) in the intention-to-treat population. This study is registered with ClinicalTrials.gov, number NCT01520519 and is no longer accruing patients. Findings Between February 28, 2012 and September 11, 2012, we enrolled 40 CLL patients with high-risk disease features. 20 patients had del17p or TP53 mutations (16 previously treated, 4 untreated), 13 had relapsed CLL with del11q, and 7 patients a PFS < 36 months after frontline chemo-immunotherapy. Toxicity was mainly of mild to moderate severity (grade 1–2). 10 (25%) patients had diarrhea (grade 1 in 9 [22.5%] patients, grade 2 in 1 [2.5%]), bleeding events occurred in 14 (35%) patients (8 [20%] patients with grade 1, 5 [12.5%] patients grade 2, and 1 [2.5%] grade 3), nausea in 15 (37.5) patients (10 [25%] grade 1, 5 [12.5%] grade 2), and fatigue in 7 (17.5%) patients (4 [10%] grade 1, 3 [7.5%] grade 2). Grade 3 infections occurred in 4 patients (10%), no grade 4 or 5 infections occurred. At 18 months, the Kaplan Meier estimate of progression-free survival was 78% (95% CI 60.6–88.5) (del[17p] or TP53 mutation: 72%, 95% CI: 45.6–87.6) Interpretation Ibrutinib in combination with rituximab is a well-tolerated regimen for patients with high-risk CLL. It induces high rates of remissions and has positive impact on QOL in this difficult-to-treat patient population. These encouraging data merit further investigation of the added benefit of rituximab as combination partner for ibrutinib in an ongoing randomized trial, in which single-agent ibrutinib is compared to iR combination therapy (NCT02007044). Funding Pharmacyclics, Inc., Cancer Prevention and Research Institute of Texas (CPRIT), Leukemia & Lymphoma Society, NCI Grant P30 CA016672, MD Anderson’s Moon Shot Program in CLL, and MD Anderson Cancer Center Support Grant CA016672.

Purpose RG7112 is a small-molecule MDM2 antagonist. MDM2 is a negative regulator of the tumor suppressor p53 and frequently overexpressed in leukemias. Thus, a Phase I study of RG7112 in patients with hematologic malignancies was conducted. Experimental Design Primary study objectives included determination of the dose and safety profile of RG7112. Secondary objectives included evaluation of pharmacokinetics, pharmacodynamics, such as TP53-mutation status and MDM2 expression, and preliminary clinical activity. Patients were divided into 2 cohorts: Stratum A (relapsed/refractory AML (except APL), ALL, and CML) and Stratum B (relapsed/refractory CLL/sCLL). Some Stratum A patients were treated at the MTD to assess clinical activity. Results RG7112 was administered to 116 patients (96 patients in Stratum A and 20 patients in Stratum B). All patients experienced at least 1 adverse event, and 3 DLTs were reported. PK analysis indicated that twice-daily dosing enhanced daily exposure. Anti-leukemia activity was observed in the 30 patients with AML assessed at the MTD included 5 patients who met IWG criteria for response. Exploratory analysis revealed TP53 mutations in 14% of Stratum A patients and in 40% of Stratum B patients. Two patients with TP53 mutations exhibited clinical activity. p53 target genes were induced only in TP53 wild-type leukemic cells. Baseline expression levels of MDM2 correlated positively with clinical response. Conclusions RG7112 demonstrated clinical activity against relapsed/refractory AML and CLL/sCLL. MDM2 inhibition resulted in p53 stabilization and transcriptional activation of p53-target genes. We provide proof-of-concept that MDM2 inhibition restores p53 function and generates clinical responses in hematologic malignancies.

Background-Therapy-related myeloid neoplasms (t-MNs) are often fatal secondary malignancies. Risk factors for t-MNs are not well understood. Recent studies suggested that individuals with clonal hematopoiesis have higher risk of developing hematological malignancies. We hypothesized that cancer patients with clonal hematopoiesis have increased risk of developing t-MNs.

Current prognostic models for myelodysplastic syndromes (MDS) do not allow the identification of patients with lower risk disease and poor prognosis that may benefit from early therapeutic intervention. We evaluated the characteristics of 856 patients with low or intermediate-1 disease by the International Prognostic Scoring System. Mean follow-up was 19.6 months (range 1-262). Of these patients, 87 (10%) transformed to acute myelogenous leukemia, and 429 (50%) had died. By multivariate analysis, characteristics associated with worse survival (Po0.01) were low platelets, anemia, older age, higher percent of marrow blasts and poor-risk cytogenetics. Although not included in the model, higher ferritin (P ¼ 0.007) and b2-microglobulin (Po0.001) levels were associated with worse prognosis. This allowed the development of a scoring system in which patients could be grouped in three categories: category 1 (n ¼ 182, 21%) with a median survival of 80.3 months (95% CI 68-NA); category 2 (n ¼ 408, 48%) with a median survival of 26.6 months (95% CI 22-32) and category 3 (n ¼ 265, 31%) with a median survival of 14.2 months (95% CI 13-18). In summary, this analysis indicates that it is possible to identify patients with lower risk MDS and poor prognosis who may benefit from early intervention.

The clinical challenge posed by p53 abnormalities in hematological malignancies requires therapeutic strategies other than standard genotoxic chemotherapies. ONC201 is a first-in-class small molecule that activates p53-independent apoptosis, has a benign safety profile, and is in early clinical trials. We found that ONC201 caused p53-independent apoptosis and cell cycle arrest in cell lines and in mantle cell lymphoma (MCL) and acute myeloid leukemia (AML) samples from patients; these included samples from patients with genetic abnormalities associated with poor prognosis or cells that had developed resistance to the nongenotoxic agents ibrutinib and bortezomib. Moreover, ONC201 caused apoptosis in stem and progenitor AML cells and abrogated the engraftment of leukemic stem cells in mice while sparing normal bone marrow cells. ONC201 caused changes in gene expression similar to those caused by the unfolded protein response (UPR) and integrated stress responses (ISRs), which increase the translation of the transcription factor ATF4 through an increase in the phosphorylation of the translation initiation factor eIF2α. However, unlike the UPR and ISR, the increase in ATF4 abundance in ONC201-treated hematopoietic cells promoted apoptosis and did not depend on increased phosphorylation of eIF2α. ONC201 also inhibited mammalian target of rapamycin complex 1 (mTORC1) signaling, likely through ATF4-mediated induction of the mTORC1 inhibitor DDIT4. Overexpression of BCL-2 protected against ONC201-induced apoptosis, and the combination of ONC201 and the BCL-2 antagonist ABT-199 synergistically increased apoptosis. Thus, our results suggest that by inducing an atypical ISR and p53-independent apoptosis, ONC201 has clinical potential in hematological malignancies.

Background Controversy persists about optimal mammography screening strategies. Objective To evaluate mammography strategies considering screening and treatment advances. Design Collaboration of six simulation models. Data Sources National data on incidence, risk, breast density, digital mammography performance, treatment effects, and other-cause mortality. Target Population An average-risk cohort. Time Horizon Lifetime. Perspective Societal. Interventions Mammograms from age 40, 45 or 50 to 74 at annual or biennial intervals, or annually from 40 or 45 to 49 then biennially to 74, assuming 100% screening and treatment adherence. Outcome Measures Screening benefits (vs. no screening) include percent breast cancer mortality reduction, deaths averted, and life-years gained. Harms include number of mammograms, false-positives, benign biopsies, and overdiagnosis. Results for Average-Risk Women Biennial strategies maintain 79.8%-81.3% (range across strategies and models: 68.3–98.9%) of annual screening benefits with almost half the false-positives and fewer overdiagnoses. Screening biennially from ages 50–74 achieves a median 25.8% (range: 24.1%-31.8%) breast cancer mortality reduction; annual screening from ages 40–74 years reduces mortality an additional 12.0% (range: 5.7%-17.2%) vs. no screening, but yields 1988 more false-positives and 7 more overdiagnoses per 1000 women screened. Annual screening from ages 50–74 had similar benefits as other strategies but more harms, so would not be recommended. Sub-population Results Annual screening starting at age 40 for women who have a two- to four-fold increase in risk has a similar balance of harms and benefits as biennial screening of average-risk women from 50–74. Limitations We do not consider other imaging technologies, polygenic risk, or non-adherence. Conclusion These results suggest that biennial screening is efficient for average-risk groups, but decisions on strategies depend on the weight given to the balance of harms and benefits. Primary Funding Source National Institutes of Health