Challenges and Opportunities for Quantitative Clinical Pharmacology in Cancer Immunotherapy: Something Old, Something New, Something Borrowed, and Something Blue.

Cancer immunotherapy (CIT) initiates or enhances the host immune response against cancer. Following decades of development, patients with previously few therapeutic options may now benefit from CIT. Although the quantitative clinical pharmacology (qCP) of previous classes of anticancer drugs has matured during this time, application to CIT may not be straightforward since CIT acts via the immune system. Here we discuss where qCP approaches might best borrow or start anew for CIT.

Modeling Alzheimer's Disease Progression Using Disease Onset Time and Disease Trajectory Concepts Applied to CDR-SOB Scores From ADNI.

Disease-onset time (DOT) and disease trajectory concepts were applied to derive an Alzheimer's disease (AD) progression population model using the clinical dementia rating scale-sum of boxes (CDR-SOB) from the AD neuroimaging initiative (ADNI) database. The model enabled the estimation of a DOT and a disease trajectory for each patient. The model also allowed distinguishing fast and slow-progressing subpopulations according to the functional assessment questionnaire, normalized hippocampal volume, and CDR-SOB score at study entry. On the basis of these prognostic factors, 81% of the mild cognitive impairment (MCI) subjects could correctly be assigned to slow or fast progressers, and 77% of MCI to AD conversions could be predicted whereas the model described correctly 84% of the conversions. Finally, synchronization of the biomarker-time profiles on estimated individual DOT virtually expanded the population observation period from 3 to 8 years. DOT-disease trajectory model is a powerful approach that could be applied to many progressive diseases.CPT: Pharmacometrics & Systems Pharmacology (2013) 2, e78; doi:10.1038/psp.2013.54; advance online publication 2 October 2013.

Assessment of the bioequivalence of two nelfinavir tablet formulations under fed and fasted conditions in healthy subjects.

OBJECTIVES: This study was designed to assess the bioequivalence between the commercial 250 mg nelfinavir tablet and the new 625 mg nelfinavir tablet (Roche) which was developed to reduce the daily pill burden for patients from 10 to 4 tablets in a nelfinavir 1250 mg twice daily regimen. METHODS: A total of 52 healthy male subjects were enrolled in this randomized four-period crossover study to receive single oral doses of 1250 mg nelfinavir administered as five commercial 250 mg tablets (reference formulation) and as two new 625 mg tablets (test formulation). Each of the two formulations were taken after an overnight fast and immediately after intake of a standard breakfast (820 kcal) on separate occasions. Blood samples were collected pre-dose and at appropriate intervals after drug administration. Plasma concentrations of nelfinavir and its main metabolite M8 were assayed by a validated LC-MS/ MS assay and the pharmacokinetics of nelfinavir and M8 were derived using standard non-compartmental analysis. RESULTS: The primary parameters for bioequivalence testing were the logarithmically transformed AUC(0-inf) and C(max) of nelfinavir taken from 50 subjects who completed all four treatments. Bioequivalence was accepted if the 90% confidence interval (CI) was contained entirely in the equivalence region (80%, 125%). In the fed state, this criterion was met for AUC (effect ratio = 95%; CI = 87%, 103%) and Cmax (effect ratio = 101%; CI = 94%, 109%) and bioequivalence of the two treatments could be concluded. In the fasted state, AUC clearly failed to meet the bioequivalence criteria (effect ratio = 73%; CI = 59%, 90%) and Cmax was borderline outside the lower acceptance region (effect ratio = 97%; CI = 79.6%, 118%). Therefore, bioequivalence could not be concluded under fasted condition. Food increased the systemic exposure to nelfinavir (as reflected by comparison of the logarithmically transformed AUC(0-inf) values under fed and fasted conditions) by six- and eight-fold after dosing with the 250 mg and the 625 mg tablet, respectively. CONCLUSIONS: Bioequivalence of the new 625 mg nelfinavir tablet relative to the commercial 250 mg tablet, at a dose of 1250 mg, was confirmed in the fed state but not under fasted conditions. As nelfinavir is recommended to be taken with food, the new tablet is well-suited to decrease the daily pill burden for patients on a nelfinavir twice daily regimen and to enhance patient's compliance and adherence.