Efficacy and safety of ruxolitinib in patients with myelofibrosis and low platelet count (50 × 109/L to <100 × 109/L) at baseline: the final analysis of EXPAND.

Background: Thrombocytopenia is a common feature of myelofibrosis (MF), a myeloproliferative neoplasm driven by dysregulated JAK/STAT signaling; however, pivotal trials assessing the efficacy of ruxolitinib (a JAK1/2 inhibitor) excluded MF patients with low platelet counts (<100 × 109/L). Objectives: Determination of the maximum safe starting dose (MSSD) of ruxolitinib was the primary endpoint, with long-term safety and efficacy as secondary and exploratory endpoints, respectively. Design: EXPAND (NCT01317875) was a phase 1b, open-label, ruxolitinib dose-finding study in patients with MF and low platelet counts (50 to <100 × 109/L). Methods: Patients were stratified according to baseline platelet count into stratum 1 (S1, 75 to <100 × 109/L) or stratum 2 (S2, 50 to <75 × 109/L). Previous analyses established the MSSD at 10 mg twice daily (bid); long-term results are reported here. Results: Of 69 enrolled patients, 38 received ruxolitinib at the MSSD (S1, n = 20; S2, n = 18) and are the focus of this analysis. The incidence of adverse events was consistent with the known safety profile of ruxolitinib, with thrombocytopenia (S1, 50%; S2, 78%) and anemia (S1, 55%; S2, 44%) the most frequently reported adverse events and no new or unexpected safety signals. Substantial clinical benefits were observed for patients in both strata: 50% (10/20) and 67% (12/18) of patients in S1 and S2, respectively, achieved a spleen response (defined as ⩾50% reduction in spleen length from baseline) at any time during the study. Conclusion: The final safety and efficacy results from EXPAND support the use of a 10 mg bid starting dose of ruxolitinib in patients with MF and platelet counts 50 to <100 × 109/L. Registration: ClinicalTrials.gov NCT01317875.

Evaluation of drug-drug interactions between midostaurin and strong CYP3A4 inhibitors in patients with FLT-3-mutated acute myeloid leukemia (AML).

PURPOSE: Midostaurin, approved for the treatment of newly diagnosed, FLT3-mutated acute myeloid leukemia (AML), is metabolized by cytochrome P450 3A4 (CYP3A4). Midostaurin with concomitant strong CYP3A4 inhibitors use (e.g., antifungal azoles) may result in drug-drug interactions. This post hoc analysis of RATIFY phase 3 study data evaluated effects of strong CYP3A4 inhibitor use on the exposure and safety of midostaurin. METHODS: Trough concentrations were used to assess midostaurin and metabolite exposure in the presence and absence of strong CYP3A4 inhibitors. Adverse event (AE) frequency was assessed in patients who received concomitant strong CYP3A4 inhibitors vs those who did not. Time to first clinically notable AE (CNAE) was also assessed in patients with high midostaurin plasma exposure vs those of matched placebo controls. RESULTS: Use of concomitant strong CYP3A4 inhibitors was most frequent during the induction phase (60.8%). A 1.44-fold increase in midostaurin plasma exposure was observed in patients with concomitant strong CYP3A4 inhibitor use vs those without. Midostaurin-treated patients who received concomitant strong CYP3A4 inhibitors experienced grade 3/4 infection-related AEs more frequently vs those who did not. Patients with high levels of midostaurin exposure had a shorter median time to first grade 3/4 CNAE vs placebo controls (36 vs 41 days, respectively; P = .012). CONCLUSION: Although concomitantly administered strong CYP3A4 inhibitors increased midostaurin exposure 1.44-fold, no clinically relevant differences in safety were noted. Midostaurin dose adjustment is not necessary with concomitant strong CYP3A4 inhibitors in patients with FLT3-mutated AML; however, caution is advised, and patients should be closely monitored.

Pharmacokinetics of Nilotinib in Pediatric Patients with Philadelphia Chromosome-Positive Chronic Myeloid Leukemia or Acute Lymphoblastic Leukemia.

PURPOSE: We investigated nilotinib exposure in pediatric patients with chronic myeloid leukemia (CML) or Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL) resistant to, relapsed on, refractory to, or intolerant of previous treatment. PATIENTS AND METHODS: Fifteen patients (aged 1-<18 years) with CML resistant to or intolerant of imatinib and/or dasatinib (n = 11) or Ph+ ALL relapsed on or refractory to standard therapy (n = 4) enrolled in this phase I study. Nilotinib (230 mg/m2 twice daily; equivalent to the adult 400-mg twice-daily dose) was administered orally in 12 or 24 cycles of 28 days. The primary objective was to characterize the pharmacokinetics of nilotinib in pediatric patients. RESULTS: The area under the concentration-time curve at steady state was slightly lower in pediatric patients versus adults (14,751.4 vs. 17,102.9 ng/h/mL); the geometric mean ratio (GMR; pediatric:adult) was 0.86 [90% confidence interval (CI), 0.70-1.06]. Body surface area-adjusted systemic clearance was slightly higher in pediatric versus adult patients (GMR, 1.30; 90% CI, 1.04-1.62). Nilotinib was generally well tolerated. The most common adverse events were headache, vomiting, increased blood bilirubin, and rash. Three patients with CML achieved major molecular response, and three with Ph+ ALL achieved complete remission. CONCLUSIONS: Nilotinib 230 mg/m2 twice daily in pediatric patients provided a pharmacokinetics and safety profile comparable with the adult reference dose; clinical activity was demonstrated in both CML and Ph+ ALL. This dose is recommended for further evaluation in pediatric patients. The safety profile was consistent with that in adults.

[Premenstrual dysphoric disorder is often overlooked].

Premenstrual dysphoric disorder (PMDD) is a cluster of severe affective symptoms recurring during the luteal phase of the menstrual cycle, and it affects up to 8% of menstruating women. In Denmark, this disorder is often overlooked. Unlike in the treatment of anxiety and depression, selective serotonin reuptake inhibitors need not be given continuously but can be effective when used only in the luteal phase. This review provides an overview of the current knowledge on the diagnosis and treatment of PMDD in Denmark.

Modelling PK/QT relationships from Phase I dose-escalation trials for drug combinations and developing quantitative risk assessments of clinically relevant QT prolongations.

In current industry practice, it is difficult to assess QT effects at potential therapeutic doses based on Phase I dose-escalation trials in oncology due to data scarcity, particularly in combinations trials. In this paper, we propose to use dose-concentration and concentration-QT models jointly to model the exposures and effects of multiple drugs in combination. The fitted models then can be used to make early predictions for QT prolongation to aid choosing recommended dose combinations for further investigation. The models consider potential correlation between concentrations of test drugs and potential drug-drug interactions at PK and QT levels. In addition, this approach allows for the assessment of the probability of QT prolongation exceeding given thresholds of clinical significance. The performance of this approach was examined via simulation under practical scenarios for dose-escalation trials for a combination of two drugs. The simulation results show that invaluable information of QT effects at therapeutic dose combinations can be gained by the proposed approaches. Early detection of dose combinations with substantial QT prolongation is evaluated effectively through the CIs of the predicted peak QT prolongation at each dose combination. Furthermore, the probability of QT prolongation exceeding a certain threshold is also computed to support early detection of safety signals while accounting for uncertainty associated with data from Phase I studies. While the prediction of QT effects is sensitive to the dose escalation process, the sensitivity and limited sample size should be considered when providing support to the decision-making process for further developing certain dose combinations. Copyright © 2016 John Wiley & Sons, Ltd.

A Bayesian approach to dose-finding studies for cancer therapies: incorporating later cycles of therapy.

We consider phase I dose-finding studies for cytotoxic drugs in cancer, where the objective is identification of a target dose (TD100δ ) associated with the probability δ of a dose-limiting toxicity (DLT). Previous authors have presented a design utilising a Bayesian decision procedure based on a logistic regression model to describe the relationship between dose and the risk of a DLT (LRDP). A cautious prior, chosen to ensure that the first cohort of patients are given the lowest dose, is combined with binary observations of DLTs to update model parameters and choose a safe dose for the next cohort. This process continues with each new cohort of patients. Typically, only DLTs occurring in the first treatment cycle are included. To incorporate data from later cycles, a new Bayesian decision procedure based on an interval-censored survival model (ICSDP) has been developed. This models the probability that the first DLT occurs in each specific cycle via the probability of a DLT during a specific cycle, conditional on having no DLT in any previous cycle. The second cohort of patients start after responses have been obtained from the first cycle of the first cohort, and subsequently, dose selection for each new cohort is based on DLTs observed across all completed cycles for all patients. A simulation study comparing the ICSDP and LRDP showed that the ICSDP induces faster updating of the current estimate of the target dose, leading to shorter trials and fewer patients, whilst keeping the same level of accuracy.

Drug misuse by patients in an inner-city hospital.

AIM: To identify the prevalence of drug misuse (illicit, over-the-counter and prescribed) by patients at Bristol Royal Infirmary, an inner-city teaching hospital, and the problems encountered by ward staff in the management of these patients. METHOD: A prevalence survey was conducted in the A&E department of the hospital using an adapted version of the two-item conjoint screening test (TICS), a validated screening tool devised by Brown et al (1997). A qualitative survey of ward managers was used to identify the problems presented by drug misusers on the ward, and to gather suggestions for the role of a specialist substance misuse liaison worker. RESULTS: An 11 per cent prevalence of drug misuse was found among 64 patients attending the A&E department. In the survey of 18 ward managers, ten (55.5 per cent) wards admitted a minimum of one drug misuser each week and 15 wards (83 per cent) described negative behaviours among this patient group which had an effect on the management of the ward. CONCLUSION: Consideration should be given to routine screening for the presence of drug misuse among patients. Introduction of a specialist drug misuse liaison worker and guidelines for the management of this patient group would help to reduce the significant problems experienced by staff.