Food and Drug Administration Public Workshop Summary-Development Considerations of Antifungal Drugs to Address Unmet Medical Need.

Pressing challenges in the treatment of invasive fungal infections (IFIs) include emerging and rare pathogens, resistant/refractory infections, and antifungal armamentarium limited by toxicity, drug-drug interactions, and lack of oral formulations. Development of new antifungal drugs is hampered by the limitations of the available diagnostics, clinical trial endpoints, prolonged trial duration, difficulties in patient recruitment, including subpopulations (eg, pediatrics), and heterogeneity of the IFIs. On 4 August 2020, the US Food and Drug Administration convened a workshop that included IFI experts from academia, industry, and other government agencies to discuss the IFI landscape, unmet need, and potential strategies to facilitate the development of antifungal drugs for treatment and prophylaxis. This article summarizes the key topics presented and discussed during the workshop, such as incentives and research support for drug developers, nonclinical development, clinical trial design challenges, lessons learned from industry, and potential collaborations to facilitate antifungal drug development.

FDA Public Workshop Summary-Addressing Challenges in Inhaled Antifungal Drug Development.

Allergic bronchopulmonary aspergillosis and invasive fungal diseases represent distinct infectious entities that cause significant morbidity and mortality. Currently, administered inhaled antifungal therapies are unapproved, have suboptimal efficacy, and are associated with considerable adverse reactions. The emergence of resistant pathogens is also a growing concern. Inhaled antifungal development programs are challenged by inadequate nonclinical infection models, highly heterogenous patient populations, low prevalence rates of fungal diseases, difficulties defining clinical trial enrollment criteria, and lack of robust clinical trial endpoints. On September 25, 2020, the US Food and Drug Administration (FDA) convened a workshop with experts in pulmonary medicine and infectious diseases from academia, industry, and other governmental agencies. Key discussion topics included regulatory incentives to facilitate development of inhaled antifungal drugs and combination inhalational devices, limitations of existing nonclinical models and clinical trial designs, patient perspectives, and industry insights.

A Regulatory Review Approach for Evaluation of Micafungin for Treatment of Neonatal Candidiasis.

Pathogenesis of neonatal candidiasis (NC) is distinct from systemic candidiasis in adults and older pediatric patients due to the significant incidence of central nervous system involvement in neonates. Thus, although adequate and well-controlled trials in NC are often unfeasible due to difficulty enrolling patients, extrapolation of efficacy from antifungal drug trials in adults is generally not appropriate. However, treatment of NC is an area of great unmet need. We describe a regulatory review approach that combined the assessment of limited clinical efficacy, pharmacokinetics, and safety data from neonates and young infants along with microbiology outcomes and pharmacokinetic data from relevant nonclinical models of candidemia/invasive candidiasis to inform the use of micafungin in pediatric patients younger than 4 months, while communicating areas of remaining uncertainty in labeling.

Effect of Body Weight and Age on the Pharmacokinetics of Dihydroartemisinin: Food and Drug Administration Basis for Dose Determination of Artesunate for Injection in Pediatric Patients With Severe Malaria.

For treatment of severe malaria, the World Health Organization recommends 3 mg/kg intravenous artesunate in pediatric patients weighing less than 20 kg. Here we describe the Food and Drug Administration's rationale for selecting 2.4 mg/kg in pediatric patients weighing less than 20 kg based on literature review and independent analyses.

Amoxicillin for postexposure inhalational anthrax in pediatrics: rationale for dosing recommendations.

We reviewed information about the safety and plasma pharmacokinetic data for amoxicillin, specifically related to its potential use for postexposure inhalational anthrax. Amoxicillin (45 mg/kg/d) given orally in 3 divided doses to pediatric patients <40 kg should yield an adequate time above the MIC for susceptible Bacillus anthracis (< or =0.5 microg/mL) over most of the dosing interval (75-100%). Doses <45 mg/kg/d and dosing intervals longer than 8 hours should not be used for postexposure inhalational anthrax.

New era in drug interaction evaluation: US Food and Drug Administration update on CYP enzymes, transporters, and the guidance process.

Predicting clinically significant drug interactions during drug development is a challenge for the pharmaceutical industry and regulatory agencies. Since the publication of the US Food and Drug Administration's (FDA's) first in vitro and in vivo drug interaction guidance documents in 1997 and 1999, researchers and clinicians have gained a better understanding of drug interactions. This knowledge has enabled the FDA and the industry to progress and begin to overcome these challenges. The FDA has continued its efforts to evaluate methodologies to study drug interactions and communicate recommendations regarding the conduct of drug interaction studies, particularly for CYP-based and transporter-based drug interactions, to the pharmaceutical industry. A drug interaction Web site was established to document the FDA's current understanding of drug interactions (http://www.fda.gov/cder/drug/drugInteractions/default.htm). This report provides an overview of the evolution of the drug interaction guidances, includes a synopsis of the steps taken by the FDA to revise the original drug interaction guidance documents, and summarizes and highlights updated sections in the current guidance document, Drug Interaction Studies-Study Design, Data Analysis, and Implications for Dosing and Labeling.