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Chapagain, M.

Publications and source records attributed to Chapagain, M..

2 recordsLinked to original sources

Systematic and quantitative analyses of pre-clinical Mycobacterium avium Lung Disease Tools for Drug Development and Transition from Animal Models to New Approach Methodologies

Animal and new approach methodologies such as the hollow fiber system model [HFS] are used for Mycobacterium avium-complex [MAC] lung disease [LD] preclinical drug development. Our objective was to perform a systematic review to benchmark these pre-clinical tools. We performed a literature search to identify preclinical pharmacokinetics/pharmacodynamics [PK/PD] studies for MAC-LD. Preferred Reporting Items for Systematic Reviews and Meta-analyses was used for bias minimization. Twenty HFS-MAC and 3 mouse studies met PK/PD inclusion criteria. We created a novel quality score tool based on predictors of clinical response, design optimization, and information theory. The quality score was judged high in 10%, good in 50%, adequate in 30%, and poor in 10% of studies. Monte Carlo experiments for PK/PD target attainment were reported in 61% of studies. On repetitive sampling, the PK/PD target exposure estimate varied significantly between sampling days in 76% of studies. The solution was ordinary differential equations with parameter outputs such as {gamma} [nonlinear kill-slope] and time-to-extinction applied to both HFS-MAC and patients sputa CFU/mL output. Next, we ranked the antibiotics by extent of microbial kill as fold-improvement over guideline-based therapy. The three top ranked drugs for microbial kill were omadacycline [69-fold], tedizolid [19-fold], and ceftriaxone [8-fold]. We recommend the HFS-MAC as tractable for exposure-effect and dose-fractionation studies, ranking antibiotics effect, and for translation to clinical doses. The analyses inform us of HFS-MAC recommendations for regulatory authorities and drug developers, including quality scores for optimal PK/PD design for target identification, resistance suppression, and choice of the best novel regimen.

pharmacology and toxicology↗

Novel tuberculosis combination regimens of two and three-months therapy duration

The tuberculosis treatment duration is 4-6 months, but can be 18-20 months with multidrug resistance. Ultrashort regimens that cure regardless of resistance status ["pan-tuberculosis regimens"] would be a major step towards global tuberculosis control. Starting with seven drugs [bedaquiline, delamanid, pretomanid, OPC-167832, sutezolid, moxifloxacin, and pyrazinamide] in clinical testing, we calculated that there were thousands of possible novel combinations to evaluate. We used mathematical and pharmacokinetics/pharmacodynamic-based hollow fiber modeling to reduce this complexity to nine combinations, which we tested. Each regimens fast and slow growth bacteria kill-slope trajectories and times-to-extinction were estimated and translated to minimum required therapy duration in patients. Sputum microbial kill trajectories of two combination regimens that have undergone clinical testing were correctly predicted by this approach. Four pan-tuberculosis regimens were predicted to achieve relapse-free cure after 2-3 months therapy in patients. The kill-slopes were used to design expedited clinical trials that minimize patients risks.

pharmacology and toxicology↗