Amikacin Liposome Inhalation Suspension for Mycobacterium avium Complex Lung Disease: A 12-Month Open-Label Extension Clinical Trial

Intrapulmonary pharmacokinetics of SPR719 following oral administration of SPR720 to healthy volunteers

SPR720 is a phosphate ester prodrug that is converted rapidly in vivo to SPR719, the active moiety, which exhibits potent in vitro activity against clinically relevant mycobacterial species including Mycobacterium avium complex (MAC) and Mycobacterium abscessus. SPR720 is in clinical development for the treatment of nontuberculous mycobacterial pulmonary disease (NTM-PD) due to MAC. This study evaluated the safety and the intrapulmonary pharmacokinetics of SPR719 in healthy volunteers. A total of 30 subjects received oral SPR720 1,000 mg once daily for 7 days followed by bronchoscopy and bronchoalveolar lavage, with blood samples collected for plasma pharmacokinetic assessments. Mean SPR719 area under the concentration-time curve from time 0 to 24 hours (AUC0-24) and maximum concentration (Cmax) for plasma, epithelial lining fluid (ELF), and alveolar macrophages (AM) were 52,418 ng·h/mL and 4,315 ng/mL, 59,880 ng·h/mL and 5,429 ng/mL, and 128,105 ng·h/mL and 13,033 ng/mL, respectively. The ratios of ELF to total plasma concentrations of SPR719 based on AUC0-24 and Cmax were 1.14 and 1.26, and the ratios of AM to total plasma concentrations of SPR719 based on AUC0-24 and Cmax were 2.44 and 3.02, respectively. When corrected for protein binding, the ratios of ELF to unbound plasma concentrations of SPR719 for AUC0-24 and Cmax were 19.87 and 21.88, and the ratios of AM to unbound plasma concentrations of SPR719 for AUC0-24 and Cmax were 42.50 and 52.53, respectively. No unexpected safety findings were observed. Results from this study of the intrapulmonary disposition of SPR719 support further investigation of SPR720 as a potential oral agent for the treatment of patients with NTM-PD.This study is registered with Clinicaltrials.gov as NCT05955586.

Toward better cures for Mycobacterium abscessus lung disease

SUMMARYThe opportunistic pathogen Mycobacterium abscessus (Mab) causes fatal lung infections that bear similarities-and notable differences-with tuberculosis (TB) pulmonary disease. In contrast to TB, no antibiotic is formally approved to treat Mab disease, there is no reliable cure, and the discovery and development pipeline is incredibly thin. Here, we discuss the factors behind the unsatisfactory cure rates of Mab disease, namely intrinsic resistance and persistence of the pathogen, and the use of underperforming, often parenteral and toxic, repurposed drugs. We propose preclinical strategies to build injectable-free sterilizing and safe regimens: (i) prioritize oral bactericidal antibiotic classes, with an initial focus on approved agents or advanced clinical candidates to provide immediate options for desperate patients, (ii) test drug combinations early, (iii) optimize novel leads specifically for M. abscessus, and (iv) consider pharmacokinetic-pharmacodynamic targets at the site of disease, the lung lesions in which drug tolerant bacterial populations reside. Knowledge and tool gaps in the preclinical drug discovery process are identified, including validated mouse models and computational platforms to enable in vitro mouse-human translation. We briefly discuss recent advances in clinical development, the need for readouts and biomarkers that correlate with cure, and clinical trial concepts adapted to the uniqueness of Mab patient populations for new regimen development. In an era when most pharmaceutical firms have withdrawn from antimicrobial drug discovery, the breakthroughs needed to fill the regimen development pipeline will likely come from partnerships between academia, biotech, pharma, non-profit organizations, and governments, with incentives that reward cooperation.

Research Progress on Liposome Pulmonary Delivery of Mycobacterium tuberculosis Nucleic Acid Vaccine and Its Mechanism of Action

Traditional vaccines have played an important role in the prevention and treatment of infectious diseases, but they still have problems such as low immunogenicity, poor stability, and difficulty in inducing lasting immune responses. In recent years, the nucleic acid vaccine has emerged as a relatively cheap and safe new vaccine. Compared with traditional vaccines, nucleic acid vaccine has some unique advantages, such as easy production and storage, scalability, and consistency between batches. However, the direct administration of naked nucleic acid vaccine is not ideal, and safer and more effective vaccine delivery systems are needed. With the rapid development of nanocarrier technology, the combination of gene therapy and nanodelivery systems has broadened the therapeutic application of molecular biology and the medical application of biological nanomaterials. Nanoparticles can be used as potential drug-delivery vehicles for the treatment of hereditary and infectious diseases. In addition, due to the advantages of lung immunity, such as rapid onset of action, good efficacy, and reduced adverse reactions, pulmonary delivery of nucleic acid vaccine has become a hot spot in the field of research. In recent years, lipid nanocarriers have become safe, efficient, and ideal materials for vaccine delivery due to their unique physical and chemical properties, which can effectively reduce the toxic side effects of drugs and achieve the effect of slow release and controlled release, and there have been a large number of studies using lipid nanocarriers to efficiently deliver target components into the body. Based on the delivery of tuberculosis (TB) nucleic acid vaccine by lipid carrier, this article systematically reviews the advantages and mechanism of liposomes as a nucleic acid vaccine delivery carrier, so as to lay a solid foundation for the faster and more effective development of new anti-TB vaccine delivery systems in the future.

Effectiveness of Amikacin liposome inhalation suspension for refractory Mycobacterium avium complex pulmonary disease at 6 months post initiation

BACKGROUND

Amikacin  liposome inhalation suspension (ALIS) improved sputum culture conversion rate at 6 months for patients with refractory Mycobacterium avium complex pulmonary disease (MAC-PD) in an international phase 3 trial. Patient characteristics and chest high-resolution CT (HRCT) findings associated with ALIS effectiveness are poorly documented.

OBJECTIVE

We aimed to clarify ALIS effectiveness for refractory MAC-PD at 6 months, elucidating associated patient characteristics and chest CT findings.

METHODS

We reviewed medical records of 12 patients with refractory MAC-PD for whom ALIS treatment was initiated at Toho University Omori Medical Center from November 2021 through September 2022. All patients demonstrated treatment persistence for at least 3 months. They were divided into culture conversion and non-conversion groups using sputum culture conversion status after 6-month ALIS treatment initiation. Clinical and radiological characteristics were compared.

RESULTS

Seven of the 12 patients (58.3%) achieved sputum culture conversion within 6 months. The culture conversion group had shorter pre-ALIS initiation treatment duration [21 months (16-25) vs. 62 months (32-69); p = 0.045]; lower cavitary lesion incidence on HRCT (28.6% vs. 100%; p = 0.028); and fewer clarithromycin (CLA)-resistant strains [0/7 (0%) vs. 3/5 (60%); p = 0.045]. Chest HRCT findings improved in 4 of 7 (57.1%) and 1 of 5 (20%) patients in the culture conversion and non-conversion groups, respectively.

CONCLUSION

ALIS facilitated sputum culture conversion within 6 months in 58.3% of patients with refractory MAC-PD. Sputum culture conversion was significantly more frequent for CLA-susceptible strains and patients with fewer cavitary lesions. Improved CT findings after ALIS did not always correspond to sputum culture conversion.

Current challenges in pulmonary nontuberculous mycobacterial infection: a case series with literature review

BACKGROUND

The prevalence of nontuberculous mycobacteria pulmonary disease (NTM-PD), particularly caused by Mycobacterium avium complex (MAC), is rising due to improved diagnostics, increased awareness, and more susceptible populations. NTM-PD significantly affects quality of life and imposes substantial economic costs. Understanding its clinical features, risk factors, and treatment challenges is vital for enhancing patient outcomes.

PATIENTS AND METHODS

A convenience sample from the University of Connecticut Health Center and Wayne State University involving patients with NTM-PD from 2021 to 2024 was studied retrospectively. Cases were selected to demonstrate typical diagnostic and treatment challenges, followed by a multidisciplinary roundtable discussion to examine patient-centered care strategies.

RESULTS

Analysis of six cases pinpointed chronic lung conditions and immunomodulatory therapy as key risk factors. Standard treatment, involving extensive multi-drug regimens, frequently results in poor adherence due to side effects and complex management requirements. The discussions underlined the importance of a customized, interdisciplinary approach to improve treatment effectiveness and patient quality of life.

CONCLUSIONS

NTM-PD is an escalating public health issue with notable clinical and economic consequences. Managing this disease effectively demands a comprehensive, patient-centered strategy that includes precise diagnosis, flexible treatment plans, and collaborative care.

Qualitative Interviews Exploring Adverse Event Mitigation Strategies in Adults Receiving Amikacin Liposome Inhalation Suspension

INTRODUCTION

This study aimed to gain insight from patients with refractory Mycobacterium avium complex lung disease (MAC-LD) into strategies used to manage adverse events (AEs) associated with amikacin liposome inhalation suspension (ALIS).

METHODS

We conducted semi-structured interviews with US patients with refractory MAC-LD prescribed ALIS in a real-world setting. Interview transcripts were analyzed and coded to identify patterns in participants' descriptions of their ALIS treatment experiences, including AEs and their disruptiveness, and AE mitigation strategies, including participants' ratings of strategies' effectiveness. Concept saturation was also assessed.

RESULTS

Twenty participants (mean age 48.7 years; 80% women; mean ALIS duration 5.45 months) were interviewed. At the time of the interview, 15 participants (75%) had received ALIS for > 1 month and 13 (65%) were currently receiving ALIS. Participants described 44 unique AE mitigation strategies, which can be categorized into three groups: prepare for treatment; prevent increased emergence of AEs; and persist on treatment by mitigating AEs. Common strategies (reported by ≥ 50% of participants) included use of educational materials from the patient support program, localized management of throat irritation, and symptom management to reduce fatigue. Evidence of concept saturation was observed: no new strategies were identified in the last five interviews, which suggests the sample was robust enough to identify all mitigation strategies likely to be used by the broader patient population.

CONCLUSIONS

This real-world study identified a diverse set of potential AE mitigation strategies intended to help individual patients prepare for ALIS treatment, prevent the increased emergence of certain AEs, and mitigate the impact of AEs on treatment persistence. Developing a comprehensive accounting of the types of mitigation strategies in use among patients in real-world settings can inform future investigation of the effectiveness of such strategies, and support evidence-based recommendations for treatment management.

Nano-Proteolysis Targeting Chimeras (Nano-PROTACs) in Cancer Therapy

Proteolysis-targeting chimeras (PROTACs) are heterobifunctional molecules that have the capability to induce specific protein degradation. While playing a revolutionary role in effectively degrading the protein of interest (POI), PROTACs encounter certain limitations that impede their clinical translation. These limitations encompass off-target effects, inadequate cell membrane permeability, and the hook effect. The advent of nanotechnology presents a promising avenue to surmount the challenges associated with conventional PROTACs. The utilization of nano-proteolysis targeting chimeras (nano-PROTACs) holds the potential to enhance specific tissue accumulation, augment membrane permeability, and enable controlled release. Consequently, this approach has the capacity to significantly enhance the controllable degradation of target proteins. Additionally, they enable a synergistic effect by combining with other therapeutic strategies. This review comprehensively summarizes the structural basis, advantages, and limitations of PROTACs. Furthermore, it highlights the latest advancements in nanosystems engineered for delivering PROTACs, as well as the development of nano-sized PROTACs employing nanocarriers as linkers. Moreover, it delves into the underlying principles of nanotechnology tailored specifically for PROTACs, alongside the current prospects of clinical research. In conclusion, the integration of nanotechnology into PROTACs harbors vast potential in enhancing the anti-tumor treatment response and expediting clinical translation.

Treatment for non-tuberculous mycobacteria: challenges and prospects

Non-Tuberculous mycobacteria (NTM) are opportunistic environmental bacteria. Globally, NTM incidence is increasing and modeling suggests that, without new interventions, numbers will continue to rise. Effective treatments for NTM infections remain suboptimal. Standard therapy for Mycobacterium avium complex, the most commonly isolated NTM, requires a 3-drug regime taken for approximately 18 months, with rates of culture conversion reported between 45 and 70%, and high rates of relapse or reinfection at up to 60%. New therapeutic options for NTM treatment are urgently required. A survey of ongoing clinical trials for new NTM therapy listed on ClinicalTrials.Gov using the terms 'Mycobacterium avium', 'Mycobacterium abscessus', 'Mycobacterium intracellulare', 'Non tuberculous Mycobacteria' and 'Nontuberculous Mycobacteria' and a selection criterion of interventional studies using antibiotics demonstrates that most trials involve dose and combination therapy of the guideline based therapy or including one or more of; Amikacin, Clofazimine, Azithromycin and the anti-TB drugs Bedaquiline and Linezolid. The propensity of NTMs to form biofilms, their unique cell wall and expression of both acquired and intrinsic resistance, are all hampering the development of new anti-NTM therapy. Increased investment in developing targeted treatments, specifically for NTM infections is urgently required.

Amikacin liposome inhalation suspension for Mycobacterium avium complex pulmonary disease: A subgroup analysis of Japanese patients in the randomized, phase 3, CONVERT study

BACKGROUND

CONVERT, a randomized, active-controlled, global, Phase 3 trial demonstrated that patients with treatment-refractory Mycobacterium avium complex (MAC) pulmonary disease were more likely to achieve culture conversion with amikacin liposome inhalation suspension (ALIS) plus guideline-based therapy (GBT) versus those continuing on GBT alone. This subgroup analysis reports the efficacy and safety of ALIS in Japanese patients enrolled in CONVERT.

METHODS

Japanese patients aged ≥20 years with treatment-refractory MAC pulmonary disease from Japanese sites were included. Patients were randomized to receive once-daily 590 mg ALIS + GBT or GBT alone; patients converting by Month 6 remained in the study to complete 12-month treatment followed by a 12-month off-treatment period. Nonconverters exited the study at Month 8. The primary endpoint was the proportion of patients achieving culture conversion by Month 6.

RESULTS

Of the 59 Japanese patients screened, 48 were randomized to receive ALIS + GBT (n = 34) or GBT alone (n = 14), and 41/48 (85.4 %) were women. The mean (standard deviation) age of patients was 64.5 (8.6) years, and 83.3 % of patients had bronchiectasis at baseline. By Month 6, sputum culture conversion was cumulatively achieved in 9/34 (26.5 %) patients receiving ALIS + GBT versus none receiving GBT alone. Treatment-emergent adverse events were reported in 94.1 % and 100.0 % of patients receiving ALIS + GBT and GBT alone, respectively. No deaths were reported.

CONCLUSIONS

The efficacy observed in the Japanese subpopulation was largely consistent with that in the overall CONVERT study population, with more patients achieving culture conversion with ALIS + GBT versus GBT alone. Safety profiles were similar between the overall population and the Japanese subpopulation.

CLINICAL TRIAL REGISTRATION

NCT02344004.

Amikacin Liposome Inhalation Suspension in the Real-World Management of Refractory Mycobacterium avium Complex Pulmonary Disease

The increasing prevalence of Mycobacterium avium complex (MAC) pulmonary disease poses a significant therapeutic challenge, particularly due to the limited efficacy and systemic toxicity associated with conventional guideline-based therapy. Amikacin liposome inhalation suspension (ALIS) has been developed, yet its real-world application remains underreported. This retrospective analysis, conducted from March 2021 to February 2024, examined ALIS's clinical use in patients aged 20 years or older with refractory MAC pulmonary disease at our institution. The primary objective of this study is to describe the patient characteristics and clinical trajectories associated with the initiation of ALIS therapy in real-world settings for individuals diagnosed with MAC pulmonary disease. Of 11 patients initiated on ALIS, one was excluded due to financial constraints impacting continuation. The analysis proceeded with the remaining 10 subjects. The mean age of participants was 70.2 years, with a predominance of female patients (n = 7, 70%) and a higher incidence of M. avium infections (n = 6, 60%). Forty percent of the cohort (n = 4) had a history of ethambutol-induced optic neuritis leading to the cessation of the drug. The average interval from the initiation of guideline-based therapy to the start of ALIS was 8.5 ± 6.9 years (mean ± standard deviation). The majority (80%) presented with positive Gaffky scores at ALIS initiation, and a significant proportion exhibited resistance to clarithromycin and ethambutol. Comorbid conditions, including diabetes and previous cancer, were noted. The study also observed elevated anti-MAC antibody levels. Treatment duration varied, with fatigue leading to discontinuation in two cases. Treatment-emergent adverse events were documented in individual patients, each presenting with grade 1 severity: hemoptysis (n = 1, 10%), elevated creatinine levels (n = 1, 10%), and dysphonia (n = 2, 20%) were observed, respectively. Correlation analysis revealed a significant inverse relationship between body mass index (BMI) and ALIS discontinuation due to fatigue, and a positive correlation between Gaffky scores and C-reactive protein (CRP) levels. These results underscore the potential benefits and limitations of ALIS, suggesting that timely intervention and comprehensive healthcare support are crucial for optimal outcomes in the treatment of advanced MAC pulmonary disease.

Lipid-based nanomedicines for the treatment of bacterial respiratory infections: current state and new perspectives

The global threat posed by antimicrobial resistance demands urgent action and the development of effective drugs. Lower respiratory tract infections remain the deadliest communicable disease worldwide, often challenging to treat due to the presence of bacteria that form recalcitrant biofilms. There is consensus that novel anti-infectives with reduced resistance compared with conventional antibiotics are needed, leading to extensive research on innovative antibacterial agents. This review explores the recent progress in lipid-based nanomedicines developed to counteract bacterial respiratory infections, especially those involving biofilm growth; focuses on improved drug bioavailability and targeting and highlights novel strategies to enhance treatment efficacy while emphasizing the importance of continued research in this dynamic field.

Nano-Formulations for Pulmonary Delivery: Past, Present, and Future Perspectives

With the development of nanotechnology and confronting the problems of traditional pharmaceutical formulations in treating lung diseases, inhalable nano-formulations have attracted interest. Inhalable nano-formulations for treating lung diseases allow for precise pulmonary drug delivery, overcoming physiological barriers, improving aerosol lung deposition rates, and increasing drug bioavailability. They are expected to solve the difficulties faced in treating lung diseases. However, limited success has been recorded in the industrialization translation of inhalable nano-formulations. Only one relevant product has been approved by the FDA to date, suggesting that there are still many issues to be resolved in the clinical application of inhalable nano-formulations. These systems are characterized by a dependence on inhalation devices, while the adaptability of device formulation is still inconclusive, which is the most important issue impeding translational research. In this review, we categorized various inhalable nano-formulations, summarized the advantages of inhalable nano-formulations over conventional inhalation formulations, and listed the inhalable nano-formulations undergoing clinical studies. We focused on the influence of inhalation devices on nano-formulations and analyzed their adaptability. After extensive analysis of the drug delivery mechanisms, technical processes, and limitations of different inhalation devices, we concluded that vibrating mesh nebulizers might be most suitable for delivering inhalable nano-formulations, and related examples were introduced to validate our view. Finally, we presented the challenges and outlook for future development. We anticipate providing an informative reference for the field.

Diagnosis and Management of Drug-Induced Interstitial Lung Disease Associated with Amikacin Liposome Inhalation Suspension in Refractory Mycobacterium Avium Complex Pulmonary Disease: A Case Report

Amikacin liposome inhalation suspension (ALIS) is a key drug for the treatment of refractory Mycobacterium avium complex pulmonary disease (MAC-PD). Although cases of drug-induced interstitial lung disease (DIILD) by ALIS have been reported, its diagnosis is challenging due to overlapping existing pulmonary shadows, airway bleeding, exacerbation of underlying conditions, and the potential for various concurrent infections. A 72-year-old woman started treatment with ALIS for refractory MAC-PD. Three weeks later, she had a fever, cough, and appetite loss. She was hospitalized because multiple infiltrative opacities were observed on chest X-ray and chest computed tomography. Because the opacities worsened after empiric antibiotic therapy with broad-spectrum antibiotics, we initiated corticosteroid therapy, suspecting DIILD caused by ALIS, although drug lymphocyte stimulation tests for ALIS and amikacin were negative. Three days later, we found signs of improvement and quickly tapered the corticosteroids. After obtaining informed consent, we performed a drug provocation test of ALIS. Seven days later, she exhibited fever, an increased peripheral white blood cell count, and elevated serum C-reactive protein level, all of which returned to baseline 4 days after stopping ALIS, leading to a diagnosis of DIILD caused by ALIS in this patient. DIILD caused by ALIS is rare but should be carefully diagnosed to ensure that patients with refractory MAC-PD do not miss the opportunity to receive ALIS treatment.

Advancing the pipeline of cystic fibrosis clinical trials: a new roadmap with a global trial network perspective

The growing use of modulator therapies aimed at restoring cystic fibrosis transmembrane conductance regulator (CFTR) protein function in people with cystic fibrosis has fundamentally altered clinical trial strategies needed to advance new therapeutics across an orphan disease population that is now divided by CFTR modulator eligibility. The development of a robust pipeline of nucleic acid-based therapies (NABTs)-initially directed towards the estimated 10% of the cystic fibrosis population who are genetically ineligible for, or intolerant of, CFTR modulators-is dependent on the optimisation of restricted trial participant resources across multiple development programmes, a challenge that will preclude the use of gold standard placebo-controlled trials. Advancement of a full pipeline of symptomatic therapies across the entire cystic fibrosis population will be challenged by smaller effect sizes and uncertainty regarding their clinical importance in a growing modulator-treated population with more mild and stable pulmonary disease. In this Series paper, we aim to lay the foundation for clinical trial strategy and community partnership that must deviate from established and familiar precedent to advance the future pipeline of cystic fibrosis therapeutics.

Recent Advances in Strategies to Combat Bacterial Drug Resistance: Antimicrobial Materials and Drug Delivery Systems

Bacterial infection is a common clinical disease. Antibiotics have saved countless lives since their discovery and are a powerful weapon in the fight against bacteria. However, with the widespread use of antibiotics, the problem of drug resistance now poses a great threat to human health. In recent years, studies have investigated approaches to combat bacterial resistance. Several antimicrobial materials and drug delivery systems have emerged as promising strategies. Nano-drug delivery systems for antibiotics can reduce the resistance to antibiotics and extend the lifespan of novel antibiotics, and they allow targeting drug delivery compared to conventional antibiotics. This review highlights the mechanistic insights of using different strategies to combat drug-resistant bacteria and summarizes the recent advancements in antimicrobial materials and drug delivery systems for different carriers. Furthermore, the fundamental properties of combating antimicrobial resistance are discussed, and the current challenges and future perspectives in this field are proposed.

Pulmonary drug delivery for acute respiratory distress syndrome

The acute respiratory distress syndrome (ARDS) is a life-threatening condition that causes respiratory failure. Despite numerous clinical trials, there are no molecularly targeted pharmacologic therapies to prevent or treat ARDS. Drug delivery during ARDS is challenging due to the heterogenous nature of lung injury and occlusion of lung units by edema fluid and inflammation. Pulmonary drug delivery during ARDS offers several potential advantages including limiting the off-target and off-organ effects and directly targeting the damaged and inflamed lung regions. In this review we summarize recent ARDS clinical trials using both systemic and pulmonary drug delivery. We then discuss the advantages of pulmonary drug delivery and potential challenges to its implementation. Finally, we discuss the use of nanoparticle drug delivery and surfactant-based drug carriers as potential strategies for delivering therapeutics to the injured lung in ARDS.

Liposomes loaded with quercetin for resolution of lung inflammation in a lipopolysaccharide-induced mouse model of sepsis

Quercetin (QU) has been widely used as a dietary supplement and proved useful to treat lung diseases. However, the therapeutic potential of QU may be restricted because of its low bioavailability and poor water solubility. In this study, we investigated the effects of developed QU-loaded liposomes on macrophage-mediated lung inflammation.In vivo, a mouse model of sepsis induced by lipopolysaccharide challenge was used to detect the anti-inflammatory effects of liposomal QU. Hematoxylin/eosin staining and immunostaining were utilized to reveal pathological damage and leukocyte infiltration into the lung tissues. Quantitative reverse transcription-polymerase chain reaction and immunoblotting were used to determine cytokine production in the mouse lungs.In vitro, mouse RAW 264.7 macrophages were treated with free QU and liposomal QU. Cell viability assay and immunostaining were utilized to detect cytotoxicity and distribution of QU in the cells. Thein vivoresults showed that liposomal encapsulation promoted the inhibitory effects of QU on lung inflammation. Liposomal QU decreased mortality in septic mice with no obvious toxicity on vital organs. Mechanistically, the anti-inflammatory effects of liposomal QU were associated with inhibition of nuclear factor-kappa B-dependent cytokine production and inflammasome activation in macrophages. Collectively, the results showed that QU liposomes mitigated lung inflammation in septic mice through inhibition of macrophage inflammatory signaling.

Health state utility estimation of Mycobacterium Avium complex pulmonary disease using a time trade-off approach

AIMS

To obtain appropriate health state utility values for cost-effectiveness analyses of new Mycobacterium avium complex pulmonary disease (MAC-PD) treatments. The impact of MAC-PD severity and symptoms on quality of life (QoL) also were quantified.

METHODS

A questionnaire describing four health states, MAC-positive severe, MAC-positive moderate, MAC-positive mild, and MAC-negative, was developed based on St. George's Respiratory Questionnaire (SGRQ) Symptom and Activity scores from the CONVERT trial. The time trade-off (TTO) method with ping-pong titration procedure was used to estimated health state utilities. Regression analyses assessed impacts of covariates.

RESULTS

Of 319 Japanese adults (49.8% female, mean age 44.8 years), mean (95% CI) health state utility scores (MAC-positive severe, MAC-positive moderate, MAC-positive mild, and MAC-negative) were 0.252 (0.194-0.310), 0.535 (0.488-0.582), 0.816 (0.793-0.839), and 0.881 (0.866-0.896), respectively. MAC-negative state utility scores were significantly higher than MAC-positive severe (mean difference [95% CI], 0.629 [0.574-0.684]), MAC-positive moderate (0.346 [0.304-0.389]), and MAC-positive mild (0.065 [0.048-0.082]) scores (p < 0.001 each). Most participants would trade survival duration to avoid MAC-positive states (97.5% to avoid MAC-positive severe; 88.7% MAC-positive moderate; 61.4% MAC-positive mild). Regression analyses to investigate the impact of background characteristics showed similar utility differences between health states when not adjusted for covariates.

LIMITATIONS

Some participant demographics differed from the general population; however, this did not impact utility differences among health states as regression analyses adjusting for demographics did not affect these differences. Similar investigations are needed among patients with MAC-PD and in other countries.

CONCLUSIONS

This study evaluating the impact of MAC-PD on utilities using the TTO method demonstrates that differences in utilities are dependent on the severity of respiratory symptoms and their impacts on daily activities and QoL. These results could contribute to better quantification of the value of MAC-PD treatments and improve assessments of cost-effectiveness.

Advances in inhaled antibiotics for management of respiratory tract infections

PURPOSE OF REVIEW

The incidence of bacterial respiratory tract infections is growing. In a context of increasing antibiotic resistance and lack of new classes of antibiotics, inhaled antibiotics emerge as a promising therapeutic strategy. Although they are generally used for cystic fibrosis, their use in other conditions is becoming more frequent, including no-cystic fibrosis bronchiectasis, pneumonia and mycobacterial infections.

RECENT FINDINGS

Inhaled antibiotics exert beneficial microbiological effects in bronchiectasis and chronic bronchial infection. In nosocomial and ventilator-associated pneumonia, aerosolized antibiotics improve cure rates and bacterial eradication. In refractory Mycobacterium avium complex infections, amikacin liposome inhalation suspension is more effective in achieving long-lasting sputum conversion. In relation to biological inhaled antibiotics (antimicrobial peptides, interfering RNA and bacteriophages), currently in development, there is no still enough evidence that support their use in clinical practice.

SUMMARY

The effective antimicrobiological activity of inhaled antibiotics, added to their potential to overcoming resistances to systemic antibiotics, make inhaled antibiotics a plausible alternative.

Amikacin liposome and Mycobacterium avium complex: A systematic review

INTRODUCTION

The prevalence of Mycobacterium avium complex (MAC) is increasing globally. Macrolide-based multidrug regimens have been recommended as the first-line treatment for patients with MAC pulmonary disease. However, developing macrolide resistance was associated with poor treatment outcomes and increased mortality. In 2018, the U.S. Food and Drug Administration approved liposomal amikacin for inhalation (LAI) to treat refractory MAC pulmonary disease. The current systematic review aimed to evaluate LAI's outcomes and adverse events in MAC pulmonary disease.

METHODS

The systematic search was performed in PubMed/Medline, EMBASE, and the Cochrane Controlled Register of Trials (CENTRAL) up to March 8, 2022. The search terms included Mycobacterium avium complex, MAC, amikacin, and liposomal amikacin.

RESULTS

After reviewing 1284 records, four papers met the inclusion criteria, including three clinical trials and one prospective cohort study. These studies showed that adding LAI to guideline-based therapies can increase sputum culture conversion rate and achieve early sustained (negative sputum culture results for 12 months with treatment) and durable (negative sputum culture results for three months after treatment) negative sputum culture. In addition, extended LAI use was a potential benefit in patients considered refractory to initial treatment. The most prevalent treatment-emergent adverse events (TEAE) reported in the LAI group were the respiratory TEAE.

CONCLUSIONS

LAI could increase the sputum culture conversion rate and achieve early sustainable, durable negative sputum culture. However, additional large-scale research is required to confirm the results.

Liposomal amikacin and Mycobacterium abscessus: intimate interactions inside eukaryotic cells

BACKGROUND

Mycobacterium abscessus (Mabs), a rapidly growing Mycobacterium species, is considered an MDR organism. Among the standard antimicrobial multi-drug regimens against Mabs, amikacin is considered as one of the most effective. Parenteral amikacin, as a consequence of its inability to penetrate inside the cells, is only active against extracellular mycobacteria. The use of inhaled liposomal amikacin may yield improved intracellular efficacy by targeting Mabs inside the cells, while reducing its systemic toxicity.

OBJECTIVES

To evaluate the colocalization of an amikacin liposomal inhalation suspension (ALIS) with intracellular Mabs, and then to measure its intracellular anti-Mabs activity.

METHODS

We evaluated the colocalization of ALIS with Mabs in eukaryotic cells such as macrophages (THP-1 and J774.2) or pulmonary epithelial cells (BCi-NS1.1 and MucilAir), using a fluorescent ALIS and GFP-expressing Mabs, to test whether ALIS reaches intracellular Mabs. We then evaluated the intracellular anti-Mabs activity of ALIS inside macrophages using cfu and/or luminescence.

RESULTS

Using confocal microscopy, we demonstrated fluorescent ALIS and GFP-Mabs colocalization in macrophages and epithelial cells. We also showed that ALIS was active against intracellular Mabs at a concentration of 32 to 64 mg/L, at 3 and 5 days post-infection. Finally, ALIS intracellular activity was confirmed when tested against 53 clinical Mabs isolates, showing intracellular growth reduction for nearly 80% of the isolates.

CONCLUSIONS

Our experiments demonstrate the intracellular localization and intracellular contact between Mabs and ALIS, and antibacterial activity against intracellular Mabs, showing promise for its future use for Mabs pulmonary infections.

Treatment strategies with alternative treatment options for patients with Mycobacterium avium complex pulmonary disease

Diseases caused by Mycobacterium avium complex (MAC) infection in the lungs are increasing worldwide. The recurrence rate of MAC-pulmonary disease (PD) has been reported to be as high as 25-45%. A significant percentage of recurrences occurs because of reinfection with a new genotype from the environment. A focus on reducing exposure to MAC organisms from the environment is therefore an essential component of the management of this disease as well as standard MAC-PD treatment. A macrolide-containing three-drug regimen is recommended over a two-drug regimen as a standard treatment, and azithromycin is recommended rather than clarithromycin. Both the 2007 and 2020 guidelines recommend a treatment duration of MAC-PD of at least one year after the culture conversion. Previous clinical studies have reported that ethambutol could prevent macrolide resistance. Furthermore, the concomitant use of aminoglycoside, amikacin liposomal inhalation, clofazimine, linezolid, bedaquiline, and fluoroquinolone with modification of guideline-based therapy has been studied. Long-term management of MAC-PD remains challenging because of the discontinuation of multi-drug regimens and the acquisition of macrolide resistance. Moreover, the poor compliance of guideline-based therapy for MAC-PD treatment worldwide is concerning since it causes macrolide resistance. Therefore, in this review, we focus on MAC-PD treatment and summarize various treatment options when standard treatment cannot be maintained, with reference to the latest ATS/ERS/ESCMID/IDSA clinical practice guidelines revised in 2020.

Contemporary Concise Review 2021: COVID-19 and other respiratory infections

Bats are likely the primary source of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2).

Minks are highly susceptible to infection by SARS‐CoV‐2.

Transmission from asymptomatic individuals was estimated to account for over 50% of all transmissions of coronavirus disease 2019 (COVID‐19) cases.

SARS‐CoV‐2 is evolving towards more efficient aerosol transmission.

Remdesivir, baricitinib, tocilizumab and dexamethasone are frequently used for the treatment of patients with respiratory failure due to COVID‐19.

There is a rising incidence of non‐tuberculous Mycobacterium pulmonary disease globally, with a higher prevalence in Asian countries than in the Western world.

Protracted bacterial bronchitis is a common cause of chronic productive cough in childhood.

Re‐emergence of respiratory syncytial virus may occur after the relaxation of infection control measures and the reopening of borders during COVID‐19 pandemic.

Beyond antibiotics: recent developments in the diagnosis and management of nontuberculous mycobacterial infection

Nontuberculous mycobacteria (NTM) pulmonary disease represents a significant clinical challenge with suboptimal therapy and increasing prevalence globally. Although clinical practice guidelines seek to standardise the approach to diagnosis and treatment of NTM disease, a lack of robust evidence limits their utility and significant variability exists in clinical practice. Here we walk through some novel approaches in diagnosis and therapy that are under development to tackle a disease where traditional strategies are failing.

Prevalence of NTM disease is rising globally, yet current diagnostic and therapeutic strategies are lacking. This review describes some burgeoning diagnostic and therapeutic approaches, but it is clear that real progress will need more focused attention.https://bit.ly/3O0K2SP

Management of Mycobacterium avium complex and Mycobacterium abscessus pulmonary disease: therapeutic advances and emerging treatments

Nontuberculous mycobacterial pulmonary disease (NTM-PD) remains a challenging condition to diagnose and treat effectively. Treatment of NTM-PD is prolonged, frequently associated with adverse effects and has variable success. In this review, we consider the factors influencing clinicians when treating NTM-PD and discuss outcomes from key studies on the pharmacological management of Mycobacterium avium complex pulmonary disease and M. abscessus pulmonary disease. We highlight issues relating to treatment-related toxicity and provide an overview of repurposed and emerging therapies for NTM-PD.

Amikacin Liposome Inhalation Suspension Clinical Benefit-Risk Assessment for Refractory MAC Lung Disease

Mycobacterium avium complex (MAC) is the leading cause of nontuberculous mycobacterial lung disease, which can be associated with progressive lung damage and increased mortality [1]. Patients with MAC lung disease have substantial disease burden and limited treatment options [1]. Up to 40% of patients experience failure, with lengthy multidrug treatments, relapse or reinfection [2]. For patients with treatment-refractory MAC lung disease (persistent MAC-positive sputum despite ≥6 months of guideline-based therapy (GBT)), international guidelines recommend the addition of amikacin liposome inhalation suspension (ALIS) to GBT regimens [3]. In clinical trials, patients with treatment-refractory MAC lung disease had improved culture conversion with ALIS+GBT versus GBT [4, 5].

Marraset al. report a low number needed to treat and high number needed to harm supporting addition of amikacin liposome inhalation suspension to guideline-based treatments in patients with treatment-refractory Mycobacterium avium complex lung diseasehttps://bit.ly/3tPFW7D

Strategies to Overcome Biological Barriers Associated with Pulmonary Drug Delivery

While the inhalation route has been used for millennia for pharmacologic effect, the biological barriers to treating lung disease created real challenges for the pharmaceutical industry until sophisticated device and formulation technologies emerged over the past fifty years. There are now several inhaled device technologies that enable delivery of therapeutics at high efficiency to the lung and avoid excessive deposition in the oropharyngeal region. Chemistry and formulation technologies have also emerged to prolong retention of drug at the active site by overcoming degradation and clearance mechanisms, or by reducing the rate of systemic absorption. These technologies have also been utilized to improve tolerability or to facilitate uptake within cells when there are intracellular targets. This paper describes the biological barriers and provides recent examples utilizing formulation technologies or drug chemistry modifications to overcome those barriers.

The Optimized Delivery of Triterpenes by Liposomal Nanoformulations: Overcoming the Challenges

The last decade has witnessed a sustained increase in the research development of modern-day chemo-therapeutics, especially for those used for high mortality rate pathologies. However, the therapeutic landscape is continuously changing as a result of the currently existing toxic side effects induced by a substantial range of drug classes. One growing research direction driven to mitigate such inconveniences has converged towards the study of natural molecules for their promising therapeutic potential. Triterpenes are one such class of compounds, intensively investigated for their therapeutic versatility. Although the pharmacological effects reported for several representatives of this class has come as a well-deserved encouragement, the pharmacokinetic profile of these molecules has turned out to be an unwelcomed disappointment. Nevertheless, the light at the end of the tunnel arrived with the development of nanotechnology, more specifically, the use of liposomes as drug delivery systems. Liposomes are easily synthesizable phospholipid-based vesicles, with highly tunable surfaces, that have the ability to transport both hydrophilic and lipophilic structures ensuring superior drug bioavailability at the action site as well as an increased selectivity. This study aims to report the results related to the development of different types of liposomes, used as targeted vectors for the delivery of various triterpenes of high pharmacological interest.

Anti-Mycobacterial Drug Resistance in Japan: How to Approach This Problem?

Mycobacteriosis is mainly caused by two groups of species: Mycobacterium tuberculosis and non-tuberculosis mycobacteria (NTM). The pathogens cause not only respiratory infections, but also general diseases. The common problem in these pathogens as of today is drug resistance. Tuberculosis (TB) is a major public health concern. A major challenge in the treatment of TB is anti-mycobacterial drug resistance (AMR), including multidrug-resistant tuberculosis and extensively drug-resistant tuberculosis. Recently, the success rate of the treatment of drug-resistant tuberculosis (DR-TB) has improved significantly with the introduction of new and repurposed drugs, especially in industrialized countries such as Japan. However, long-term treatment and the adverse events associated with the treatment of DR-TB are still problematic. To solve these problems, optimal treatment regimens designed/tailor-made for each patient are necessary, regardless of the location in the world. In contrast to TB, NTM infections are environmentally oriented. Mycobacterium avium-intracellulare complex (MAC) and Mycobacterium abscessus species (MABS) are the major causes of NTM infections in Japan. These bacteria are naturally resistant to a wide variation of antimicrobial agents. Macrolides, represented by clarithromycin (CLR) and amikacin (AMK), show relatively good correlation with treatment success. However, the efficacies of potential drugs for the treatment of macrolide-resistant MAC and MABS are currently under evaluation. Thus, it is particularly difficult to construct an effective treatment regimen for macrolide-resistant MAC and MABS. AMR in NTM infections are rather serious in Japan, even when compared with challenges associated with DR-TB. Given the AMR problems in TB and NTM, the appropriate use of drugs based on accurate drug susceptibility testing and the development of new compounds/regimens that are strongly bactericidal in a short-time course will be highly expected.

Nontuberculous mycobacterial lung disease caused by Mycobacterium avium complex - disease burden, unmet needs, and advances in treatment developments

INTRODUCTION

Nontuberculous mycobacterial (NTM) lung disease (LD) is the most common clinical manifestation of NTM infection and is a growing health concern. Up to 85% of NTM-LD cases are caused by Mycobacterium avium complex (MAC). Increased awareness of NTM-LD caused by MAC is needed as patients with this disease experience substantial burden and unmet treatment needs.

AREAS COVERED

This review provides clinicians and regulatory and healthcare decision makers an overview of the clinical, economic, and humanistic burden of NTM-LD and the unmet treatment needs faced by patients and clinicians. The review focuses on NTM-LD caused by MAC. A summary of the 2020 NTM guidelines specifically for MAC-LD and an overview of novel treatment options, including amikacin liposome inhalation suspension (ALIS) as the first approved therapy for refractory MAC-LD, and investigational drugs in testing phase are provided.

EXPERT OPINION

Key advancements in NTM-LD management include recent updates to clinical practice guidelines, approval of ALIS for the treatment of refractory MAC-LD, and ongoing clinical trials of investigational treatments. Yet opportunities still exist to improve patient outcomes, including development of better screening tools, such as reliable and responsive biomarkers to help identify high-risk patients, and addressing unmet treatment needs.

The role of amikacin in the treatment of nontuberculous mycobacterial disease

Introduction: Guidelines recommend the use of amikacin in the treatment of nontuberculous mycobacterial (NTM) disease. The authors have evaluated the evidence for the position of amikacin in NTM disease treatment.Areas covered: The authors performed a literature search for original research on amikacin in NTM disease, including its mechanism of action, emergence of resistance, pre-clinical and clinical investigations.Expert opinion: Amikacin shows moderate in vitro activity against the clinically most relevant NTM species (M. avium complex and M. abscessus). It is synergistic with ethambutol, clofazimine, and macrolides and these combinations are effective in animal models. Liposomal encapsulation increases amikacin efficacy. Clinically, the recommended dose of 15 mg/kg intravenous amikacin does not lead to PK/PD target attainment in all patients and a positive impact on long-term treatment outcomes remains unproven in both M. avium complex and M. abscessus disease. Adding the amikacin liposome inhalation suspension did prove to be effective in short and long term in patients not responding to recommended treatment for M. avium complex pulmonary disease. Its optimal use in M. avium complex and M. abscessus pulmonary disease warrants further evaluation.

Amikacin Liposome Inhalation Suspension in Refractory Mycobacterium avium Complex Lung Disease: A Profile of Its Use

Amikacin liposome inhalation suspension (ALIS) [Arikayce^® Liposomal (EU); Arikayce^® (USA)], a liposomal suspension of the aminoglycoside amikacin (590 mg) for nebulization via the Lamira^® Nebulizer System, is available as add-on therapy for treatment-refractory Mycobacterium avium complex (MAC) lung disease in adults who have little or no alternative treatment options. Its addition to guideline-based therapy (GBT) significantly improved the likelihood of achieving sputum culture conversion (defined as three consecutive monthly MAC-negative sputum cultures) by month 6 relative to GBT alone in adults with treatment-refractory MAC lung disease, with the conversion response maintained over up to 12 months' therapy and at 3 months' post treatment in significantly higher proportions of ALIS plus GBT than GBT alone recipients. ALIS as an add-on therapy to GBT was associated with an increased risk of respiratory adverse reactions compared with GBT alone, but treatment-emergent adverse events associated with systemic amikacin exposure were uncommon.