Anaplastic lymphoma kinase inhibition in non-small-cell lung cancer.

BACKGROUND: Oncogenic fusion genes consisting of EML4 and anaplastic lymphoma kinase (ALK) are present in a subgroup of non-small-cell lung cancers, representing 2 to 7% of such tumors. We explored the therapeutic efficacy of inhibiting ALK in such tumors in an early-phase clinical trial of crizotinib (PF-02341066), an orally available small-molecule inhibitor of the ALK tyrosine kinase. METHODS: After screening tumor samples from approximately 1500 patients with non-small-cell lung cancer for the presence of ALK rearrangements, we identified 82 patients with advanced ALK-positive disease who were eligible for the clinical trial. Most of the patients had received previous treatment. These patients were enrolled in an expanded cohort study instituted after phase 1 dose escalation had established a recommended crizotinib dose of 250 mg twice daily in 28-day cycles. Patients were assessed for adverse events and response to therapy. RESULTS: Patients with ALK rearrangements tended to be younger than those without the rearrangements, and most of the patients had little or no exposure to tobacco and had adenocarcinomas. At a mean treatment duration of 6.4 months, the overall response rate was 57% (47 of 82 patients, with 46 confirmed partial responses and 1 confirmed complete response); 27 patients (33%) had stable disease. A total of 63 of 82 patients (77%) were continuing to receive crizotinib at the time of data cutoff, and the estimated probability of 6-month progression-free survival was 72%, with no median for the study reached. The drug resulted in grade 1 or 2 (mild) gastrointestinal side effects. CONCLUSIONS: The inhibition of ALK in lung tumors with the ALK rearrangement resulted in tumor shrinkage or stable disease in most patients. (Funded by Pfizer and others; ClinicalTrials.gov number, NCT00585195.).

A study of the interaction potential of azithromycin and clarithromycin with atorvastatin in healthy volunteers.

Atorvastatin is a common option among the HMG-CoA reductase inhibitors for the treatment of lipid disorders because of its excellent lipid-lowering efficacy and overall safety profile. Although these agents can rarely cause rhabdomyolysis by themselves, macrolides, among other agents, have been demonstrated to increase the likelihood of this via inhibition of CYP metabolism of the lipid agent. This study investigated the potential for azithromycin and clarithromycin to inhibit the metabolism of atorvastatin. Although there was no interaction between azithromycin and atorvastatin, clarithromycin did have a significant effect on atorvastatin pharmacokinetic parameters. When coadministered, clarithromycin raised subject exposure (AUC24) by 82% and peak plasma concentrations by 56%. These data suggest that while azithromycin appears to be safe to coadminister with atorvastatin, clarithromycin should be avoided in patients taking this and similarly metabolized HMG-CoA inhibitors.

Evaluation of methods for improving precision of blood pressure measurements in phase I clinical trials.

Small sample sizes are typically incorporated in early Phase I clinical studies, which may lead to insignificant changes in safety parameters such as blood pressure. Therefore, it is paramount to identify an optimal, noninvasive method of accurately measuring blood pressure and an appropriate analysis strategy yielding the smallest variability. The goals of this study were (1) to compare the variability between automated and manual blood pressure measurements, (2) to determine whether triplicate blood pressure measurements were independent of one another, and (3) to assess how the number of blood pressure readings affects variability and study sample size. Twenty healthy volunteers were enrolled in this randomized, two-way crossover study. Each subject received three incremental infusions of phenylephrine or normal saline on separate days to simulate blood pressure variability. The mean systolic blood pressure readings with the automated device were consistently higher than the manual device by 3 to 5 mmHg. Conversely, the mean diastolic blood pressure readings with the automated device were consistently 3 to 5 mmHg lower than the manual device. However, the variability and absolute change in blood pressure were essentially identical with manual and automated methods. No systematic order effects such as the first blood pressure reading always being higher were detected, suggesting that the triplicate readings were independent of one another and that an interval of 2 minutes between readings is adequate. Compared to a single measurement, collecting blood pressure in triplicate results in a 40% lower sample size needed to detect a 5-mmHg difference in systolic blood pressure.

Alternative confidence intervals for the assessment of bioequivalence in four-period cross-over designs.

Bioequivalence studies are conducted to demonstrate equivalence in the bioavailability of the active ingredient in different formulations. The U.S. Food and Drug Administration (FDA) requires pharmaceutical companies to show bioequivalence between different formulations or generic companies to show bioequivalence between generic drugs and brand drugs before approval. A recent FDA guidance on bioequivalence proposes criteria for assessment of population bioequivalence (PBE) and individual bioequivalence (IBE) in a four-period cross-over design. In this paper, computer simulation is used to compare modified large sample (MLS) upper bounds with those proposed by the FDA to test for both PBE and IBE. The comparison criteria are the ability to maintain the stated test size and the simulated power of tests based on these bounds.