Lack of phototoxicity potential with delafloxacin in healthy male and female subjects: comparison to lomefloxacin

Study of the impurity profile of photodegradation in lomefloxacin hydrochloride ear drops using liquid chromatography combined with ion trap/time-of-flight mass spectrometry

RATIONALE

Lomefloxacin hydrochloride ear drops are highly unstable to light and prone to produce photodegradation impurities. These impurities might be related to the phototoxicity of lomefloxacin, which could seriously threaten the health of patients. In this article, the photodegradation impurity profile in lomefloxacin hydrochloride ear drops was studied for further improvement of quality control of the drug.

METHODS

By studying the chromatographic behavior of photodegradation impurities, the photodegradation impurities in lomefloxacin hydrochloride ear drops were separated and detected effectively. Liquid chromatography combined with ion trap/time-of-flight mass spectrometry was applied to characterize the structures of the photodegradation impurities in lomefloxacin hydrochloride ear drops.

RESULTS

The structures of 17 impurities in lomefloxacin hydrochloride ear drops were elucidated based on high-resolution MSn data in positive ion mode, 12 of them being unknown impurities.

CONCLUSIONS

The structural characteristics and fragmentation patterns of the photodegradation impurities were also studied. The study of the photodegradation impurity profile in lomefloxacin hydrochloride ear drops provides a scientific basis for quality control of these ear drops and ensures the safety of drug use by the public.

Phosphorus-modified copper ferrite (P-CuFe2O4) nanoparticles for photocatalytic ozonation of lomefloxacin

Phosphorus-modified copper ferrite (P-CuFe2O4) nanoparticles were prepared by a simple sol-gel auto-combustion process and used for the photocatalytic ozonation of lomefloxacin (LOM). The morphology, crystallinity, and structure of the synthesized CuFe2O4 and P-CuFe2O4 nanoparticles were investigated using various techniques. The high-performance liquid chromatography (HPLC) analysis revealed that the degradation of LOM achieved a 99% reduction after a duration of 90 min in the photocatalytic ozonation system. In accordance with the charge-to-mass ratio, four intermediates were proposed with the help of their fragments obtained in LC-MS/MS. The degradation kinetics of lomefloxacin followed a pseudo-first order reaction, and the degradation mechanism was proposed based on the results. P0.035Cu0.965Fe2O4 showed the highest total organic carbon (TOC) removal with 20.15% in 90 min, highest specific surface area and the highest fluoride and ammonium production using the ion chromatography (IC). The experimental results obtained from the electron paramagnetic resonance (EPR) analysis indicated that the modified P-CuFe2O4 samples exhibited significantly elevated levels of superoxide (.O2-) production compared to the CuFe2O4 samples. The findings of this study demonstrate that the introduction of phosphorus modification into the copper ferrite photocatalyst led to an augmentation of both the specific surface area and the total pore volume. Furthermore, the incorporation of phosphorus served to promote the efficient separation of electron-hole pairs by effectively trapping electrons in the conduction band, hence enhancing the degradation efficiency.

Universal response method for the quantitative analysis of photodegradation impurities in lomefloxacin hydrochloride ear drops by liquid chromatography coupled with charged aerosol detector

In terms of risk assessment especially for the impurities with different ultraviolet responses, quantitative analysis without the availability of corresponding reference substances currently poses a challenge. In this study, a universal response method was established for the quantitative analysis of photodegradable impurities in lomefloxacin hydrochloride ear drops by high performance liquid chromatography-charged aerosol detector (HPLC-CAD) for the first time. The chromatographic conditions and CAD parameters were optimized for a good separation and sensitivity. The uniform response of developed method was validated by impurity reference substances with different ultraviolet responses. In the gradient compensation HPLC-CAD method validation, good linearities were obtained with coefficient of determination (R2) all greater than 0.999 for lomefloxacin and impurity reference substances. The average recoveries of the impurities were 98.63%- 102.18% by UV and 97.92%- 102.57% by CAD, respectively. RSDs all were less than 2.5% for intra-day and inter-day precision by UV and CAD, with good precision and accuracy. The correction factor experimental results showed that the developed method provided a uniform response to the impurities with differences chromophores in lomefloxacin. The effects of packaging materials and excipients on the photodegradation were also investigated using the developed method. The results of correlation analysis showed that the packaging materials with low light transmittance and the organic excipients (glycerol and ethanol) could significantly improve the stability of lomefloxacin hydrochloride ear drops. The developed HPLC-CAD quantification method was a reliable and universal response method for quantitative analysis of impurities in the lomefloxacin. This study also revealed the key factors affecting the photodegradation of lomefloxacin hydrochloride ear drops, which guided enterprises to improve drug prescription and packaging materials and ensure the public medication safety.

Overview of Side-Effects of Antibacterial Fluoroquinolones: New Drugs versus Old Drugs, a Step Forward in the Safety Profile?

Antibacterial fluoroquinolones (FQs) are frequently used in treating infections. However, the value of FQs is debatable due to their association with severe adverse effects (AEs). The Food and Drug Administration (FDA) issued safety warnings concerning their side-effects in 2008, followed by the European Medicine Agency (EMA) and regulatory authorities from other countries. Severe AEs associated with some FQs have been reported, leading to their withdrawal from the market. New systemic FQs have been recently approved. The FDA and EMA approved delafloxacin. Additionally, lascufloxacin, levonadifloxacin, nemonoxacin, sitafloxacin, and zabofloxacin were approved in their origin countries. The relevant AEs of FQs and their mechanisms of occurrence have been approached. New systemic FQs present potent antibacterial activity against many resistant bacteria (including resistance to FQs). Generally, in clinical studies, the new FQs were well-tolerated with mild or moderate AEs. All the new FQs approved in the origin countries require more clinical studies to meet FDA or EMA requirements. Post-marketing surveillance will confirm or infirm the known safety profile of these new antibacterial drugs. The main AEs of the FQs class were addressed, highlighting the existing data for the recently approved ones. In addition, the general management of AEs when they occur and the rational use and caution of modern FQs were outlined.

Preclinical safety evaluation of levonadifloxacin, a novel anti-methicillin-resistant Staphyloccocus aureus benzoquinolizine fluoroquinolone by intravenous and oral administration

Fluoroquinolone (FQ) antibacterials have drawn heightened attention from various international regulatory agencies due to their class-specific side effects. Levonadifloxacin is a novel broad spectrum benzoquinolizine FQ active against methicillin-resistant Staphyloccocus aureus (MRSA). Owing to FQ-associated safety concerns, extensive preclinical safety pharmacology (central nervous system and cardiac safety) and toxicology studies (subacute repeat-dose toxicity, genotoxicity, phototoxicity and chondrotoxicity) of levonadifloxacin were performed at relatively high doses. Intravenous (IV) and oral studies were conducted using WCK 771 (l-arginine salt of levonadifloxacin) and WCK 2349 (l-alanine ester prodrug of levonadifloxacin), respectively. Safety pharmacology studies following single dose revealed no adverse effects on central nervous system (including seizure) in mice and cardiovascular system (hERG and monkey telemetry). In repeat-dose toxicity studies, except for IV bolus dosing related effects in rat (hyperactivity, mild convulsion, polypnoea and injection site irritation) and dog (emesis and salivation), no other adverse findings limiting the dosing duration were observed. No major biochemical, haematological, gross or histopathological changes suggestive of damage to vital organs were observed in either WCK 771- or WCK 2349-treated groups. WCK 771 and WCK 2349 were found to be nongenotoxic; however, they showed weak phototoxicity that was comparable with levofloxacin. WCK 771 showed chondrotoxicity in the Beagle dog pups on repeat-dose administration; however, the severity level was lower than ofloxacin. Overall, preclinical safety studies helped establish wider safety margin for WCK 771 and WCK 2349 that supports administration of higher therapeutic doses in humans by both IV and oral routes, thereby enabling safe anti-MRSA treatment.

A profile of delafloxacin in the treatment of adults with community-acquired bacterial pneumonia

INTRODUCTION

Community-acquired bacterial pneumonia (CABP) is the most common infectious cause of hospital admission in adults, and poses a significant clinical and economic burden. At the same time, antimicrobial resistance is increasing worldwide with only a few new antibiotics developed in recent years. Delafloxacin is an anionic fluoroquinolone available in intravenous and oral formulations and with a broad spectrum of activity targeting Gram-positives, including methicillin-resistant Staphylococcus aureus (MRSA), gram-negative organisms, and atypical and anaerobic organisms. It also has a better adverse event profile compared to other fluoroquinolones.

AREAS COVERED

This article reviews the current epidemiology of CABP, etiologic agents and current resistance rates, current treatment guidelines, characteristics of delafloxacin (chemistry, microbiology, PK/PD), clinical efficacy and safety in pneumonia and other indications, and regulatory affairs.

EXPERT OPINION

: Delafloxacin's susceptibility profile against respiratory pathogens, bioequivalent intravenous and oral formulations and favorable safety profile, support its use for the treatment of CABP. It could be useful as empirical treatment in countries with high rates of penicillin-resistant S. pneumoniae and in patients with suspected or documented pneumonia due to MRSA. In post-influenza staphylococcal bacterial pneumonia, MRSA could be also considered an important pathogen.

Delafloxacin: A Review in Community-Acquired Pneumonia

Delafloxacin (BAXDELA^® in the USA; Quofenix^® in the EU) is an anionic fluoroquinolone antibacterial that is approved for the treatment of community-acquired pneumonia (CAP) and acute bacterial skin and skin structure infections in adults. Delafloxacin demonstrated in vitro activity against Gram-positive and Gram-negative pathogens, including drug-resistant isolates. In a phase III trial in adults with CAP, delafloxacin was noninferior to moxifloxacin when assessed against FDA- and EMA-defined primary endpoints, with both fluoroquinolones achieving high treatment success rates. A prespecified subgroup analysis suggested that delafloxacin may be more efficacious than moxifloxacin in patients with a history of asthma or chronic obstructive pulmonary disease (COPD). Delafloxacin was generally well tolerated in patients with CAP, with most treatment-emergent adverse events graded as mild or moderate in severity. Fluoroquinolone-associated adverse events of special interest occurred infrequently, with no events of QT prolongation or phototoxicity reported with delafloxacin. Delafloxacin is an effective and generally well-tolerated treatment that increases the number of available treatments for CAP and, although further research is required, may be a useful option for patients with CAP and comorbid asthma or COPD.

Ciprofloxacin-Resistant Pseudomonas aeruginosa Lung Abscess Complicating COVID-19 Treated with the Novel Oral Fluoroquinolone Delafloxacin

Purpose

We report the development of a lung abscess caused by a ciprofloxacin-resistant Pseudomonas aeruginosa in a patient with COVID-19 on long-term corticosteroid therapy. Successful antimicrobial treatment included the novel oral fluoroquinolone delafloxacin suggesting an oral administration option for ciprofloxacin-resistant Pseudomonas aeruginosa lung abscess. Case Presentation. An 86-year-old male was admitted to the hospital with fever, dry cough, and fatigue. PCR testing from a nasopharyngeal swab confirmed SARS-CoV-2 infection. An initial CT scan of the chest showed COVID-19 typical peripheral ground-glass opacities of both lungs. The patient required supplemental oxygen, and anti-inflammatory treatment with corticosteroids was initiated. After four weeks of corticosteroid therapy, the follow-up CT scan of the chest suddenly showed a new cavernous formation in the right lower lung lobe. The patient's condition deteriorated requiring high-flow oxygen support. Consequently, the patient was transferred to the intensive care unit. Empiric therapy with intravenous piperacillin/tazobactam was started. Mycobacterial and fungal infections were excluded, while all sputum samples revealed cultural growth of P. aeruginosa. Antimicrobial susceptibility testing showed resistance to meropenem, imipenem, ciprofloxacin, gentamicin, and tobramycin. After two weeks of treatment with intravenous piperacillin/tazobactam, the clinical condition improved significantly, and supplemental oxygen could be stopped. Subsequently antimicrobial treatment was switched to oral delafloxacin facilitating an outpatient management.

Conclusion

Our case demonstrates that long-term corticosteroid administration in severe COVID-19 can result in severe bacterial coinfections including P. aeruginosa lung abscess. To our knowledge, this is the first reported case of a P. aeruginosa lung abscess whose successful therapy included oral delafloxacin. This is important because real-life data for the novel drug delafloxacin are scarce, and fluoroquinolones are the only reliable oral treatment option for P. aeruginosa infection. Even more importantly, our case suggests an oral therapy option for P. aeruginosa lung abscess in case of resistance to ciprofloxacin, the most widely used fluoroquinolone in P. aeruginosa infection.

Efficacy and safety of delafloxacin, ceftaroline, ceftobiprole, and tigecycline for the empiric treatment of acute bacterial skin and skin structure infections: A network meta-analysis of randomized controlled trials

Background

Method

Results

Conclusion

Current pharmacotherapy for methicillin-resistant Staphylococcus aureus (MRSA) pneumonia

INTRODUCTION

Currently, several antibiotics are active against methicillin-resistant Staphylococcus aureus (MRSA) and can be used for the treatment of pneumonia. They show great variability in terms of antibiotic class, indication, pharmacodynamic/pharmacokinetic properties, type of available formulations, spectrum of activity against bacteria other than MRSA, and toxicity profile.

AREAS COVERED

In this narrative review, the authors discuss the characteristics of currently available agents for the treatment of MRSA pneumonia.

EXPERT OPINION

The availability of different agents with anti-MRSA activity, and approved for the treatment of pneumonia can allow a personalized approach for any given patient based on the severity of the disease, the setting of occurrence, the patient's baseline risk of toxicity and drug interactions, and the possibility of oral therapy whenever early discharge or outpatient treatment are possible. Although some gray areas still remain, like the lack of high certainty evidence on the efficacy of some old agents and on the precise role of companion agents with toxin inhibitory activity in the case of necrotizing pneumonia, the frequent availability of different treatment choices, each with peculiar characteristics, is already allowing an important step toward a precision medicine approach for the treatment of MRSA pneumonia.

Photodiagnostic services in the UK and Republic of Ireland: a British Photodermatology Group Workshop Report

BACKGROUND

Photodiagnostic investigations are essential for the accurate diagnosis of abnormal cutaneous photosensitivity and provide important information for the management of patients with photodermatoses (cutaneous photosensitivity disorders). Although photodiagnosis has been undertaken since the early 1970s, specialist services in the United Kingdom (UK) and Republic of Ireland are limited and there is no formal guidance on diagnostic approach. Indeed, there is a limited literature in this area of methodology and diagnostic practice.

OBJECTIVES

The primary objective was to undertake a British Photodermatology Group Workshop to review the role and activities of specialist centres in the UK and Republic of Ireland in order to ascertain whether there were consensus practices. Secondary objectives were to identify key priorities for service, training and research.

METHODS

An initial detailed survey review of current activities was undertaken prior to the Workshop and data from this survey were used to inform discussion at the Workshop, which was attended by key photodermatology experts from the UK and Republic of Ireland.

RESULTS/CONCLUSIONS

We have undertaken a detailed review of current Photodiagnostic Services in the UK and Republic of Ireland and report on our findings from the 12 centres and we have identified key areas of consensus practice. This is an important step in the process of standardising and optimising procedures and protocols and defining minimum clinical standards for photodiagnostic investigations, which are of such diagnostic importance in Dermatology.

Delafloxacin as a treatment option for community-acquired pneumonia infection

Community-acquired pneumonia (CAP) is a leading cause of morbidity and mortality in adults. Bacterial pathogens are recognized to be frequent causative agents, which makes antibacterial treatment crucial for the evolution of these patients. There are several antimicrobial options available in daily practice. However, bacterial resistance is a problem. The chemical, pharmacokinetic, pharmacodynamics, and safety characteristics of delafloxacin, a fluoroquinolone, are discussed. The data from one phase 3 clinical trial evaluating the use of delafloxacin in adults with community-acquired pneumonia is also discussed, along with findings from other meaningful studies. In vitro data have shown that delafloxacin has broad spectrum activity. Results from phase 2 and phase 3 studies have demonstrated that delafloxacin use is safe. International guidelines have recommended respiratory fluoroquinolones as second option for non-severe cases and must be considered in very severe patients not improving to a betalactam/macrolide combination. Delafloxacin was compared to moxifloxacin in the phase 3 community-acquired pneumonia trial. Serious and life-long adverse events due to fluoroquinolones use have been recently reported. Delafloxacin may possibly replace currently available fluoroquinolones, particularly in the treatment of resistant pathogens, such as ciprofloxacin-resistant P. aeruginosa isolates when other drugs are inefficient.

Delafloxacin: A Review in Acute Bacterial Skin and Skin Structure Infections

The global spread of antibacterial-resistant strains, especially methicillin-resistant Staphylococcus aureus (MRSA) for acute bacterial skin and skin structure infections (ABSSSIs), has driven the need for novel antibacterials. Delafloxacin [Quofenix™ (EU); Baxdela^® (USA)], a new fluoroquinolone (FQ), has a unique chemical structure that enhances its antibacterial activity in acidic environments such as occurs in ABSSSIs (including S. aureus infections). Delafloxacin (intravenous and oral formulations) is approved in several countries for the treatment of adults with ABSSSIs (featured indication). In intent-to-treat analyses in pivotal phase 3 trials in adults with ABSSSIs, including those with comorbid disease, intravenous delafloxacin monotherapy (± oral switch after six doses) twice daily was noninferior to intravenous vancomycin + aztreonam for primary endpoints, as specified by the FDA (objective response rate at 48–78 h after initiation of therapy) and the EMA [investigator-assessed clinical cure rate at the follow-up visit at day 14 (± 1 day)]. Delafloxacin was generally well tolerated, with most treatment-related adverse events mild to moderate in severity and few patients discontinuing treatment because of these events. Relative to vancomycin + aztreonam (a non-FQ regimen), delafloxacin treatment was not associated with an increased risk of FQ-associated AEs of special interest. Given its unique chemical structure that confers novel properties relative to other FQ and its broad spectrum of activity against common clinically relevant Gram-positive pathogens, including against MRSA strains (± FQ-resistance mutations), and Gram-negative pathogens, intravenous delafloxacin (± oral switch) provides a novel emerging option for the treatment of adult patients with ABSSSIs.

New Antibiotics for Multidrug-Resistant Bacterial Strains: Latest Research Developments and Future Perspectives

The present work aims to examine the worrying problem of antibiotic resistance and the emergence of multidrug-resistant bacterial strains, which have now become really common in hospitals and risk hindering the global control of infectious diseases. After a careful examination of these phenomena and multiple mechanisms that make certain bacteria resistant to specific antibiotics that were originally effective in the treatment of infections caused by the same pathogens, possible strategies to stem antibiotic resistance are analyzed. This paper, therefore, focuses on the most promising new chemical compounds in the current pipeline active against multidrug-resistant organisms that are innovative compared to traditional antibiotics: Firstly, the main antibacterial agents in clinical development (Phase III) from 2017 to 2020 are listed (with special attention on the treatment of infections caused by the pathogens Neisseria gonorrhoeae, including multidrug-resistant isolates, and Clostridium difficile), and then the paper moves on to the new agents of pharmacological interest that have been approved during the same period. They include tetracycline derivatives (eravacycline), fourth generation fluoroquinolones (delafloxacin), new combinations between one β-lactam and one β-lactamase inhibitor (meropenem and vaborbactam), siderophore cephalosporins (cefiderocol), new aminoglycosides (plazomicin), and agents in development for treating drug-resistant TB (pretomanid). It concludes with the advantages that can result from the use of these compounds, also mentioning other approaches, still poorly developed, for combating antibiotic resistance: Nanoparticles delivery systems for antibiotics.

Analysis of Pooled Phase 3 Safety Data for Delafloxacin in Acute Bacterial Skin and Skin Structure Infections

Background

Through improved understanding of the structure-activity relationship attributes of fluoroquinolones, molecule development has improved efficacy, safety, and tolerability of the class. Adverse events (AEs) associated with the fluoroquinolones are well defined and a prospective part of the development process. However, not all fluoroquinolones have the same AE profile with different substitutions on the core molecule resulting in differences in side effects and spectrum of activity. Unique structural attributes of delafloxacin (DLX) may differentiate its AE profile compared to other fluoroquinolones. This analysis compared the incidence of AEs between DLX and vancomycin/aztreonam across two phase 3 ABSSSI studies in order to provide a broader overview of DLX safety.

Methods

Safety events occurring in all subjects in the pivotal phase 3 trials were pooled to provide a broad overview of DLX safety.

Results

DLX was safe and well-tolerated in the pooled phase 3 ABSSSI trial population of 741 subjects. Treatment-emergent AEs (TEAEs) were seen in the DLX group versus the comparator group at 45.1% and 47.7%, respectively. Most were mild or moderate in severity. Treatment-related TEAEs were reported in the DLX group versus the comparator group at rates of 22.1% and 26.1%, respectively.

Conclusions

Available data show DLX is well tolerated in both intravenous and oral formulation for the treatment of ABSSSI and does not appear to be associated with increased risk of AEs associated with other fluoroquinolones. It remains important to monitor for potential AEs that have been observed with other fluoroquinolones.

Photosensitivity induced by lomefloxacin versus other fluoroquinolones: A meta-analysis

Lomefloxacin may be more likely than other fluoroquinolones to cause photosensitivity. However, the rate of photosensitivity is variable and a meta-analysis has yet to be performed. The aim of this meta-analysis is to compare the rate of photosensitivity between outpatients who received lomefloxacin and those who received other fluoroquinolones. PubMed, EMBASE, Cochrane Library databases and trial registries were searched for randomized controlled trials (RCTs) of outpatients through June 12, 2019. The study outcome was the rate of photosensitivity based on the intention-to-treat principle, estimated by risk difference (RD) as the primary analysis and Peto odds ratio (Peto OR) as the secondary analysis, with 95% confidence intervals (CIs) using random-effects models. Four RCTs (total of 2295 patients) were included in this meta-analysis. A statistically higher risk of photosensitivity was found with lomefloxacin than with other fluoroquinolones (RD, 3.4%; 95% CI, 0.7%-6.2%; P-value = 0.013; I² = 10.9%). The odds of photosensitivity was also significantly higher with lomefloxacin (Peto OR, 5.81; 95% CI, 3.34 to 10.11; P-value <0.001; I² = 0%). This meta-analysis of RCTs found significantly higher photosensitivity with lomefloxacin compared to other fluoroquinolones. Considering this finding and given its lack of additional efficacy compared to other fluoroquinolones, lomefloxacin as a fluoroquinolone option should potentially be reconsidered.

The safety of treatment options for acute bacterial skin and skin structure infections

INTRODUCTION

Acute bacterial skin and skin-structure infections (ABSSSI) may develop in both in-patients and out-patients, possibly with a severe clinical presentation. Since most phase 3 randomized clinical trials have shown non-inferiority in efficacy across different agents, considerations regarding their different safety profiles inevitably play a crucial role in the everyday choice about which of them should be employed for the treatment of ABSSSI.

AREAS COVERED

In this review, the authors discuss the safety profile of different treatment options for ABSSSI.

EXPERT OPINION

The spread of methicillin-resistant Staphylococcus aureus (MRSA) in the last decades has inevitably influenced the therapeutic approach to ABSSSI. Adequate knowledge of the peculiar toxicity profile of each drug active against MRSA is essential for guiding, monitoring and managing adverse events, in turn reducing any unfavorable impact of toxicity on patients' outcomes. In the next five years, potential toxicity will play a critical role in establishing the best available therapy for each specific patient, together with consideration regarding the possibility of avoiding hospitalization or allowing a switch from intravenous to oral therapy and early discharge.

Delafloxacin for the Treatment of Acute Bacterial Skin and Skin Structure Infections

Objective: To review the microbiological activity, safety, and efficacy of the new fluoroquinolone delafloxacin for the treatment of acute bacterial skin and skin structure infections (ABSSSIs). Data Sources: A PubMed search from 1945 to September 2018 was done using the terms delafloxacin, acute bacterial skin and skin structure infections, skin and soft tissue infections, and fluoroquinolone. Additional sources include the Food and Drug Administration website, ClinicalTrials.gov, and the Melinta Therapeutics website. Study Selection and Data Extraction: The literature search was limited to those published in the English language and included in vitro and human studies that evaluated microbiological coverage, pharmacokinetics, pharmacodynamics, safety, and/or efficacy. Data Synthesis: Delafloxacin is a new fluoroquinolone with a unique structure for its class that covers both methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas. This new antibiotic has demonstrated noninferiority to vancomycin plus aztreonam for the treatment of ABSSSIs in both an intravenous-only regimen and an intravenous to an oral regimen. Relevance to Patient Care and Clinical Practice: ABSSSIs are infections that are most often caused by Staphylococcus and represent one of the most common types of hospital infections. MRSA represents about half of all staphylococcal skin infections, and along with gram-negative infections, increase the rates of patient morbidity and health care costs. Delafloxacin is an additional treatment option that covers both of these types of microorganisms. Conclusions: Delafloxacin is a safe and effective treatment option for ABSSSIs, particularly in those with polymicrobial infections and those with MRSA.

Perspectives on synthetic pharmacotherapy for the treatment of nosocomial pneumonia

Introduction: Nosocomial pneumonia is the second most common infection in hospital settings, resulting in substantial increases in morbidity, mortality, and length of hospital stay. The rapid increase in resistance of nosocomial pathogens to many antibiotics and the high dissemination of resistance genes highlight the need for innovative approaches to combat difficult-to-treat nosocomial respiratory infections. Areas covered: This review summarizes the synthetic antimicrobials that are currently in development for the treatment of nosocomial pneumonia, focusing on antibiotics in the final phases of clinical development and on the strategies employed by novel synthetic antimicrobial peptides. Expert opinion: Several novel synthetic antimicrobials are currently in the pipeline, and it appears that new antimicrobial peptides or mimetics will soon be made available, expanding the opportunities to treat nosocomial pneumonia. However, the approval process for use in the treatment of nosocomial pneumonia is arduous. Given that significant investments by pharmaceutical companies have ended in failure to obtain the approval of regulatory agencies, novel platforms for antimicrobial discovery are needed. The identification of new and fully synthetic chemical structures with activity against nosocomial pathogens needs to be followed by preclinical studies in large animals and by pharmacokinetic and pharmacodynamic studies in specific critically ill populations to assess lung penetration.

Profile of a Novel Anionic Fluoroquinolone-Delafloxacin

Fluoroquinolones have been in clinical use for over 50 years with significant efficacy. However, increasing resistance and emergence of some marked adverse events have limited their usage. The most recently approved class member, delafloxacin, is the only available anionic (non-zwitterionic) fluoroquinolone. Its unique molecular structure provides improved in vitro activity against most Gram-positive pathogens, including quinolone-resistant strains, which is further enhanced at acid pH. Delafloxacin shows favorable pharmacological properties, with about 60% bioavailability after oral administration, only mild inhibition of cytochrome P450 3A, and no evidence of cardiac- or phototoxicity in healthy volunteers (tested against positive controls). Its twice daily dosing, suitability for intravenous, oral, or switch dosing, the lack of many clinically significant drug-drug interactions, and acceptable adverse event profile in registration clinical trials supports its use in the treatment of acute bacterial skin and skin structure infections, and potentially in other infections, where resistance to other agents, safety, and/or the need for early discharge is of concern.

Drug and chemical induced photosensitivity from a clinical perspective

Drug photosensitivity is a relatively common occurrence and a range of mechanisms may be involved. Some of these mechanisms will be discussed, including the most common, that of drug phototoxicity. Different types of photosensitivity are addressed with respect to clinical presentation, mechanisms and additionally the contribution to our understanding through clinically directed investigations and regulatory requirements. Repeated controlled therapeutic use of drug phototoxicity, with psoralen-UVA (PUVA) photochemotherapy and photodynamic therapy (PDT) will also be discussed. Finally, the potential for drug-induced photocarcinogenesis will also be covered.

Safety of Delafloxacin: Focus on Adverse Events of Special Interest

Background

Fluoroquinolones have been widely used for a variety of Gram-positive and Gram-negative infections, and by 2002 they had become the most commonly prescribed class of antibiotics for adults in the United States. With widespread use, the class has become associated with a range of adverse events. Delafloxacin is a fluoroquinolone approved in the United States for the treatment of adults with acute bacterial skin and skin structure infections (ABSSSIs). Delafloxacin is differentiated from other fluoroquinolones due to structural differences and in its activity against methicillin-resistant Staphylococcus aureus, including quinolone-resistant strains. This paper reviews the safety profile of delafloxacin across clinical studies with an emphasis on the incidence of adverse events of special interest that are associated with fluoroquinolones.

Methods

Data from 2 completed phase III studies of delafloxacin for the treatment of ABSSSIs were pooled and are the primary focus of this paper. Additional support from the full safety analysis set (30 completed phase I to phase III clinical studies) is included where applicable.

Results

Fewer patients in the pooled delafloxacin group had AESIs than in the comparator group (7.0% vs 9.2%, respectively). Delafloxacin had a low rate of discontinuations due to treatment-related adverse events (<1%). Serious adverse events occurred at similar rates in patients treated with delafloxacin vs comparators.

Conclusions

Serious adverse events occurred at similar rates in patients treated with delafloxacin vs nonquinolone comparators used to treat ABSSSIs.

Clinicaltrials.gov identifier

NCT01984684 and NCT01811732