Supratherapeutic Tacrolimus Concentrations With Nirmatrelvir/Ritonavir in Solid Organ Transplant Recipients Requiring Hospitalization: A Case Series Using Rifampin for Reversal.

Nirmatrelvir/ritonavir was recently granted emergency use authorization for mild to moderate coronavirus disease 2019. Drug-drug interactions between ritonavir and tacrolimus are underappreciated by nontransplant providers. We describe 2 solid organ transplant recipients prescribed nirmatrelvir/ritonavir for outpatient use who developed tacrolimus toxicity requiring hospitalization and were managed with rifampin for toxicity reversal.

Pro-myogenic small molecules revealed by a chemical screen on primary muscle stem cells.

Satellite cells are the canonical muscle stem cells that regenerate damaged skeletal muscle. Loss of function of these cells has been linked to reduced muscle repair capacity and compromised muscle health in acute muscle injury and congenital neuromuscular diseases. To identify new pathways that can prevent loss of skeletal muscle function or enhance regenerative potential, we established an imaging-based screen capable of identifying small molecules that promote the expansion of freshly isolated satellite cells. We found several classes of receptor tyrosine kinase (RTK) inhibitors that increased freshly isolated satellite cell numbers in vitro. Further exploration of one of these compounds, the RTK inhibitor CEP-701 (also known as lestaurtinib), revealed potent activity on mouse satellite cells both in vitro and in vivo. This expansion potential was not seen upon exposure of proliferating committed myoblasts or non-myogenic fibroblasts to CEP-701. When delivered subcutaneously to acutely injured animals, CEP-701 increased both the total number of satellite cells and the rate of muscle repair, as revealed by an increased cross-sectional area of regenerating fibers. Moreover, freshly isolated satellite cells expanded ex vivo in the presence of CEP-701 displayed enhanced muscle engraftment potential upon in vivo transplantation. We provide compelling evidence that certain RTKs, and in particular RET, regulate satellite cell expansion during muscle regeneration. This study demonstrates the power of small molecule screens of even rare adult stem cell populations for identifying stem cell-targeting compounds with therapeutic potential.

Accelerating anticancer drug development - opportunities and trade-offs.

The traditional approach to drug development in oncology, with discrete phases of clinical testing, is becoming untenable owing to expansion of the precision medicine paradigm, whereby patients are stratified into multiple subgroups according to the underlying cancer biology. Seamless approaches to drug development in oncology hold great promise of accelerating the accessibility of novel therapeutic agents to the public but are also accompanied by important trade-offs, including the limited availability of information on the clinical benefit and safety of novel agents at the time of market entry. In this Perspectives article, we describe several opportunities, in the form of novel trial designs or modelling strategies, to improve the efficiency of drug development in oncology, as well as new mechanisms to obtain information about anticancer therapies throughout their life cycle, such as innovative functional imaging techniques or the use of real-world clinical data.

Inhibition of PIP4Kγ ameliorates the pathological effects of mutant huntingtin protein.

The discovery of the causative gene for Huntington's disease (HD) has promoted numerous efforts to uncover cellular pathways that lower levels of mutant huntingtin protein (mHtt) and potentially forestall the appearance of HD-related neurological defects. Using a cell-based model of pathogenic huntingtin expression, we identified a class of compounds that protect cells through selective inhibition of a lipid kinase, PIP4Kγ. Pharmacological inhibition or knock-down of PIP4Kγ modulates the equilibrium between phosphatidylinositide (PI) species within the cell and increases basal autophagy, reducing the total amount of mHtt protein in human patient fibroblasts and aggregates in neurons. In two Drosophila models of Huntington's disease, genetic knockdown of PIP4K ameliorated neuronal dysfunction and degeneration as assessed using motor performance and retinal degeneration assays respectively. Together, these results suggest that PIP4Kγ is a druggable target whose inhibition enhances productive autophagy and mHtt proteolysis, revealing a useful pharmacological point of intervention for the treatment of Huntington's disease, and potentially for other neurodegenerative disorders.

Improving the management of acute coronary syndrome for Aboriginal and non-Aboriginal patients in a regional hospital.

OBJECTIVES: To determine inequities in clinical adherence to national diagnostic and management guidelines for acute coronary syndrome (ACS) for Aboriginal and non-Aboriginal ACS patients at a regional hospital. METHODS: Covering two study periods (2011-12; 2013-14), records of Aboriginal (n=276) and a random selection of non-Aboriginal patients (n=333) presenting to the Emergency Department with chest pain were retrospectively reviewed using an audit protocol. Groups were compared using logistic regression, controlling for age, sex and comorbidity. RESULTS: Pathway utilisation improved overall, but risk stratification improved only for non-Aboriginal patients (OR=3.34, 95%CI 1.88-5.94). Performance of two troponin measurements increased to 88% for both Aboriginal and non-Aboriginal presentations. Although initially higher for non-Aboriginal presentations, the likelihood of admission was found to be similar in the repeat audit (75.6% vs 78.6%; p=0.60), reflecting a rise in Aboriginal presentations being admitted (OR=2.30, 95%CI 1.27-4.15). There was no significant difference in proportions transferred, receiving angiograms or for ST Elevation Acute Coronary Syndrome (a severe form of Acute Coronary Syndrome) being thrombolysed. Discharge against medical advice remained higher among Aboriginal presentations (OR=4.22, 95%CI 0.88-20.29). CONCLUSIONS AND IMPLICATIONS: Although there was a general improvement in adherence to the chest pain pathway and a reduction in inequity in the treatment of Aboriginal people, there is continuing need for improvement in adherence to guidelines to optimise the management of ACS in this regional setting.

A Multidisciplinary Children's Airway Center: Impact on the Care of Patients With Tracheostomy.

BACKGROUND: Children with complex airway problems see multiple specialists. To improve outcomes and coordinate care, we developed a multidisciplinary Children's Airway Center. For children with tracheostomies, aspects of care targeted for improvement included optimizing initial hospital discharge, promoting effective communication between providers and caregivers, and avoiding tracheostomy complications. METHODS: The population includes children up to 21 years old with tracheostomies. The airway center team includes providers from pediatric pulmonology, pediatric otolaryngology/head and neck surgery, and pediatric gastroenterology. Improvement initiatives included enhanced educational strategies, weekly care conferences, institutional consensus guidelines and care plans, personalized clinic schedules, and standardized intervals between airway examinations. A patient database allowed for tracking outcomes over time. RESULTS: We initially identified 173 airway center patients including 123 with tracheostomies. The median number of new patients evaluated by the center team each year was 172. Median hospitalization after tracheostomy decreased from 37 days to 26 days for new tracheostomy patients <1 year old discharged from the hospital. A median of 24 care plans was evaluated at weekly conferences. Consensus protocol adherence increased likelihood of successful decannulation from 68% to 86% of attempts. The median interval of 8 months between airway examinations aligned with published recommendations. CONCLUSIONS: For children with tracheostomies, our Children's Airway Center met and sustained goals of optimizing hospitalization, promoting communication, and avoiding tracheostomy complications by initiating targeted improvements in a multidisciplinary team setting. A multidisciplinary approach to management of these patients can yield measurable improvements in important outcomes.

Routine use of continuous, hyperfractionated, accelerated radiotherapy for non-small-cell lung cancer: a five-center experience.

PURPOSE: To report the results from continuous, hyperfractionated, accelerated radiotherapy (CHART) used as the standard fractionation for radical RT in the management of non-small cell lung cancer (NSCLC) in five United Kingdom centers. METHODS AND MATERIALS: In 2005, the CHART consortium identified six U.K. centers that had continued to use CHART after the publication of the CHART study in 1997. All centers had been using CHART for >5 years and agreed to use a common database to audit their results. Patients treated with CHART between 1998 and December 2003 were identified to allow a minimum of 2 years of follow-up. Patient demographics, tumor characteristics, treatment details, and survival were recorded retrospectively. Five centers completed the data collection. RESULTS: A total of 583 patients who had received CHART were identified. Of these patients, 69% were male, with a median age of 68 years (range, 31-89); 83% had performance status 0 or 1; and 43% had Stage I or II disease. Of the 583 patients, 99% received the prescribed dose. In only 4 patients was any Grade 4-5 toxicity documented. The median survival from the start of RT was 16.2 months, and the 2-year survival rate of 34% was comparable to that reported in the original study. CONCLUSION: The results of this unselected series have confirmed that CHART is deliverable in routine clinical practice, with low levels of toxicity. Importantly, this series has demonstrated that the results of CHART reported from the randomized trial can be reproduced in routine clinical practice.