Model‐informed drug development (MIDD) has a long and rich history in infectious diseases. This review describes foundational principles of translational anti‐infective pharmacology, including choice ...of appropriate measures of exposure and pharmacodynamic (PD) measures, patient subpopulations, and drug‐drug interactions. Examples are presented for state‐of‐the‐art, empiric, mechanistic, interdisciplinary, and real‐world evidence MIDD applications in the development of antibacterials (review of minimum inhibitory concentration‐based models, mechanism‐based pharmacokinetic/PD (PK/PD) models, PK/PD models of resistance, and immune response), antifungals, antivirals, drugs for the treatment of global health infectious diseases, and medical countermeasures. The degree of adoption of MIDD practices across the infectious diseases field is also summarized. The future application of MIDD in infectious diseases will progress along two planes; “depth” and “breadth” of MIDD methods. “MIDD depth” refers to deeper incorporation of the specific pathogen biology and intrinsic and acquired‐resistance mechanisms; host factors, such as immunologic response and infection site, to enable deeper interrogation of pharmacological impact on pathogen clearance; clinical outcome and emergence of resistance from a pathogen; and patient and population perspective. In particular, improved early assessment of the emergence of resistance potential will become a greater focus in MIDD, as this is poorly mitigated by current development approaches. “MIDD breadth” refers to greater adoption of model‐centered approaches to anti‐infective development. Specifically, this means how various MIDD approaches and translational tools can be integrated or connected in a systematic way that supports decision making by key stakeholders (sponsors, regulators, and payers) across the entire development pathway.
Ripretinib is a switch control KIT kinase inhibitor approved for treatment of adults with advanced gastrointestinal stromal tumors who received prior treatment with 3 or more kinase inhibitors, ...including imatinib. Ripretinib and its active metabolite (DP‐5439) are cleared mainly via cytochrome P450 enzyme 3A4/5 (CYP3A4/5), and ripretinib solubility is pH‐dependent, thus the drug–drug interaction potentials of ripretinib with itraconazole (strong CYP3A inhibitor), rifampin (strong CYP3A inducer), and pantoprazole (proton pump inhibitor) were each evaluated in open‐label, fixed‐sequence study designs. Overall, 20 participants received ripretinib 50 mg alone and with itraconazole 200 mg once daily, 24 participants received ripretinib 100 mg alone and with rifampin 600 mg once daily, and 25 participants received ripretinib 50 mg alone and with pantoprazole 40 mg once daily. Ripretinib exposure increased with concomitant itraconazole, with geometric least‐squares (LS) mean ratios of ripretinib area under the concentration–time curve from 0 to ∞ (AUC0–∞) and maximum observed concentration (Cmax) of 199% and 136%. Ripretinib exposure decreased with concomitant rifampin: geometric LS mean ratios for ripretinib AUC0–∞ and Cmax were 39% and 82%. Pantoprazole coadministration had no effect on ripretinib pharmacokinetics. No unexpected safety signals occurred. No dose adjustment is required for ripretinib coadministered with gastric acid reducers and strong CYP3A inhibitors; patients also receiving strong CYP3A inhibitors should be monitored more frequently for adverse reactions. Concomitant ripretinib use with strong CYP3A inducers should be avoided. Prescribers should refer to approved labeling for specific dose recommendations with concomitant use of strong and moderate CYP3A inducers.
Zanamivir serum and pulmonary pharmacokinetics were characterized following intravenous (i.v.) or oral inhaled administration. I.v. zanamivir was given as intermittent doses of 100 mg, 200 mg, and ...600 mg every 12 h (q12h) for two doses or as a continuous infusion (6-mg loading dose followed by 3 mg/h for 12 h). Oral inhaled zanamivir (two 5-mg inhalations q12h for two doses) was evaluated as well. Each zanamivir regimen was administered to six healthy subjects with serial pharmacokinetic sampling. In addition, a single bronchoalveolar lavage (BAL) fluid sample was collected at various time points and used to calculate epithelial lining fluid (ELF) drug concentrations for each subject. For intermittent i.v. administration of 100 mg, 200 mg, and 600 mg zanamivir, the median zanamivir concentrations in ELF collected 12 h after dosing were 74, 146, and 419 ng/ml, respectively, each higher than the historic mean 50% inhibitory concentrations for the neuraminidases of wild-type strains of influenza A and B viruses. Median ELF/serum zanamivir concentration ratios ranged from 55 to 79% for intermittent i.v. administration (when sampled 12 h after the last dose) and 43 to 45% for continuous infusion (when sampled 6 to 12 h after the start of the infusion). For oral inhaled zanamivir, the median zanamivir concentrations in ELF were 891 ng/ml for the first BAL fluid collection and 326 ng/ml for subsequent BAL fluid collections (when sampled 12 h after the last dose); corresponding serum drug concentrations were undetectable. This study demonstrates zanamivir's penetration into the human pulmonary compartment and supports the doses selected for the continuing development of i.v. zanamivir in clinical studies of influenza.
Abstract Background Ganciclovir protects against hearing deterioration in infants with symptomatic congenital cytomegalovirus (CMV) disease involving the central nervous system (CNS). Objectives To ...assess the neurodevelopmental impact of ganciclovir therapy in this population. Study design 100 neonates were enrolled into a controlled Phase III study of symptomatic congenital CMV involving the CNS, and were randomized to either 6 weeks of intravenous ganciclovir or no treatment. Denver developmental tests were performed at 6 weeks, 6 months, and 12 months. For each age, developmental milestones that ≥90% of normal children would be expected to have achieved were identified. The numbers of milestones not met (“delays”) were determined for each subject. The average number of delays per subject was compared for each treatment group. Results At 6 months, the average number of delays was 4.46 and 7.51, respectively, for ganciclovir recipients and “no treatment” subjects ( p = 0.02). At 12 months, the average number of delays was 10.06 and 17.14, respectively ( p = 0.007). In a multivariate regression model, the effect of ganciclovir therapy remained statistically significant at 12 months ( p = 0.007). Conclusions Infants with symptomatic congenital CMV involving the CNS receiving intravenous ganciclovir therapy have fewer developmental delays at 6 and 12 months compared with untreated infants. Based on these data as well as the previously published data regarding ganciclovir treatment and hearing outcomes, 6 weeks of intravenous ganciclovir therapy can be considered in the management of babies with symptomatic congenital CMV disease involving the CNS. If treatment is initiated, it should be started within the first month of life and patients should be monitored closely for toxicity, especially neutropenia. Since existing data only address the treatment of symptomatic congenital CMV disease involving the CNS, these data cannot be extrapolated to neonates with other manifestations of CMV disease, including asymptomatic babies and symptomatic babies who do not have CNS involvement.
Objective To evaluate the efficacy and safety of ganciclovir therapy in neonates with congenital cytomegalovirus (CMV) disease.
Study design Neonates with symptomatic CMV disease involving the ...central nervous system were randomly assigned to receive 6 weeks of intravenous ganciclovir versus no treatment. The primary end point was improved brainstem-evoked response (BSER) between baseline and 6-month follow-up (or, for patients with normal baseline hearing, normal BSER at both time points).
Results From 1991 to 1999, 100 patients were enrolled. Of these, 42 patients had both a baseline and 6-month follow-up BSER audiometric examination and thus were evaluable for the primary end point. Twenty-one (84%) of 25 ganciclovir recipients had improved hearing or maintained normal hearing between baseline and 6 months versus 10 (59%) of 17 control patients (P=.06). None (0%) of 25 ganciclovir recipients had worsening in hearing between baseline and 6 months versus 7 (41%) of 17 control patients (P<.01). A total of 43 patients had a BSER at both baseline and at 1 year or beyond. Five (21%) of 24 ganciclovir recipients had worsening of hearing between baseline and ≥1 year versus 13 (68%) of 19 control patients (P<.01). A total of 89 patients had absolute neutrophil counts determined during the course of the study; 29 (63%) of 46 ganciclovir-treated patients had grade 3 or 4 neutropenia during treatment versus 9 (21%) of 43 control patients (P<.01).
Conclusions Ganciclovir therapy begun in the neonatal period in symptomatically infected infants with CMV infection involving the central nervous system prevents hearing deterioration at 6 months and may prevent hearing deterioration at ≥1 year. Almost two thirds of treated infants have significant neutropenia during therapy.
Fosamprenavir is one of the most recently approved HIV-1 protease inhibitors (PIs) and offers reductions in pill number and pill size, and omits the need for food and fluid requirements associated ...with the earlier-approved HIV-1 PIs. Three fosamprenavir dosage regimens are approved by the US FDA for the treatment of HIV-1 PI-naive patients, including fosamprenavir 1,400 mg twice daily, fosamprenavir 1,400 mg once daily plus ritonavir 200mg once daily, and fosamprenavir 700 mg twice daily plus ritonavir 100mg twice daily. Coadministration of fosamprenavir with ritonavir significantly increases plasma amprenavir exposure. The fosamprenavir 700 mg twice daily plus ritonavir 100mg twice daily regimen maintains the highest plasma amprenavir concentrations throughout the dosing interval; this is the only approved regimen for the treatment of HIV-1 PI-experienced patients and is the only regimen approved in the European Union. Fosamprenavir is the phosphate ester prodrug of the HIV-1 PI amprenavir, and is rapidly and extensively converted to amprenavir after oral administration. Plasma amprenavir concentrations are quantifiable within 15 minutes of dosing and peak at 1.5-2 hours after fosamprenavir dosing. Food does not affect the absorption of amprenavir following administration of the fosamprenavir tablet formulation; therefore, fosamprenavir tablets may be administered without regard to food intake. Amprenavir has a large volume of distribution, is 90% bound to plasma proteins and is a substrate of P-glycoprotein. With <1% of a dose excreted in urine, the renal route is not an important elimination pathway, while the principal route of amprenavir elimination is hepatic metabolism by cytochrome P450 (CYP) 3A4. Amprenavir is also an inhibitor and inducer of CYP3A4. Furthermore, fosamprenavir is commonly administered in combination with low-dose ritonavir, which is also extensively metabolised by CYP3A4, and is a more potent CYP3A4 inhibitor than amprenavir. This potent CYP3A4 inhibition contraindicates the coadministration of certain CYP3A4 substrates and requires others to be co-administered with caution. However, fosamprenavir can be co-administered with many other antiretroviral agents, including drugs of the nucleoside/nucleotide reverse transcriptase inhibitor, non-nucleoside reverse transcriptase inhibitor and HIV entry inhibitor classes. Coadministration with other HIV-1 PIs continues to be studied.The extensive fosamprenavir and amprenavir clinical drug interaction information provides guidance on how to co-administer fosamprenavir and fosamprenavir plus ritonavir with many other commonly co-prescribed medications, such as gastric acid suppressants, HMG-CoA reductase inhibitors, antibacterials and antifungal agents.
Micro-Abstract Progression-free survival (PFS), overall survival (OS), and time to disease progression were similar between eribulin with pemetrexed and pemetrexed monotherapy (P) in second-line ...treatment of nonsquamous, non–small-cell lung cancer (NSCLC). At the eribulin dose administered for this phase II study, the combination of eribulin and pemetrexed was well tolerated; there was no therapeutic advantage with the combination of eribulin at this dose.
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