Two cases of severe pulmonary toxicity from highly active mesothelin-directed CAR T cells.

Multiple clinical studies have treated mesothelin (MSLN)-positive solid tumors by administering MSLN-directed chimeric antigen receptor (CAR) T cells. Although these products are generally safe, efficacy is limited. Therefore, we generated and characterized a potent, fully human anti-MSLN CAR. In a phase 1 dose-escalation study of patients with solid tumors, we observed two cases of severe pulmonary toxicity following intravenous infusion of this product in the high-dose cohort (1-3 × 108 T cells per m2). Both patients demonstrated progressive hypoxemia within 48 h of infusion with clinical and laboratory findings consistent with cytokine release syndrome. One patient ultimately progressed to grade 5 respiratory failure. An autopsy revealed acute lung injury, extensive T cell infiltration, and accumulation of CAR T cells in the lungs. RNA and protein detection techniques confirmed low levels of MSLN expression by benign pulmonary epithelial cells in affected lung and lung samples obtained from other inflammatory or fibrotic conditions, indicating that pulmonary pneumocyte and not pleural expression of mesothelin may lead to dose-limiting toxicity. We suggest patient enrollment criteria and dosing regimens of MSLN-directed therapies consider the possibility of dynamic expression of mesothelin in benign lung with a special concern for patients with underlying inflammatory or fibrotic conditions.

Sedation and Analgesia in Patients Undergoing Tracheostomy in COVID-19, a Multi-Center Registry.

INTRODUCTION: Patients with COVID-19 ARDS require significant amounts of sedation and analgesic medications which can lead to longer hospital/ICU length of stay, delirium, and has been associated with increased mortality. Tracheostomy has been shown to decrease the amount of sedative, anxiolytic and analgesic medications given to patients. The goal of this study was to assess whether tracheostomy decreased sedation and analgesic medication usage, improved markers of activity level and cognitive function, and clinical outcomes in patients with COVID-19 ARDS. STUDY DESIGN AND METHODS: A retrospective registry of patients with COVID-19 ARDS who underwent tracheostomy creation at the University of Pennsylvania Health System or the Johns Hopkins Hospital from 3/2020 to 12/2020. Patients were grouped into the early (≤14 days, n = 31) or late (15 + days, n = 97) tracheostomy groups and outcome data collected. RESULTS: 128 patients had tracheostomies performed at a mean of 19.4 days, with 66% performed percutaneously at bedside. Mean hourly dose of fentanyl, midazolam, and propofol were all significantly reduced 48-h after tracheostomy: fentanyl (48-h pre-tracheostomy: 94.0 mcg/h, 48-h post-tracheostomy: 64.9 mcg/h, P = .000), midazolam (1.9 mg/h pre vs. 1.2 mg/h post, P = .0012), and propofol (23.3 mcg/kg/h pre vs. 8.4 mcg/kg/h post, P = .0121). There was a significant improvement in mobility score and Glasgow Coma Scale in the 48-h pre- and post-tracheostomy. Comparing the early and late groups, the mean fentanyl dose in the 48-h pre-tracheostomy was significantly higher in the late group than the early group (116.1 mcg/h vs. 35.6 mcg/h, P = .03). ICU length of stay was also shorter in the early group (37.0 vs. 46.2 days, P = .012). INTERPRETATION: This data supports a reduction in sedative and analgesic medications administered and improvement in cognitive and physical activity in the 48-h period post-tracheostomy in COVID-19 ARDS. Further, early tracheostomy may lead to significant reductions in intravenous opiate medication administration, and ICU LOS.

Neoadjuvant Gene-Mediated Cytotoxic Immunotherapy for Non-Small-Cell Lung Cancer: Safety and Immunologic Activity.

Gene-mediated cytotoxic immunotherapy (GMCI) is an immuno-oncology approach involving local delivery of a replication-deficient adenovirus expressing herpes simplex thymidine kinase (AdV-tk) followed by anti-herpetic prodrug activation that promotes immunogenic tumor cell death, antigen-presenting cell activation, and T cell stimulation. This phase I dose-escalation pilot trial assessed bronchoscopic delivery of AdV-tk in patients with suspected lung cancer who were candidates for surgery. A single intra-tumoral AdV-tk injection in three dose cohorts (maximum 1012 viral particles) was performed during diagnostic staging, followed by a 14-day course of the prodrug valacyclovir, and subsequent surgery 1 week later. Twelve patients participated after appropriate informed consent. Vector-related adverse events were minimal. Immune biomarkers were evaluated in tumor and blood before and after GMCI. Significantly increased infiltration of CD8+ T cells was found in resected tumors. Expression of activation, inhibitory, and proliferation markers, such as human leukocyte antigen (HLA)-DR, CD38, Ki67, PD-1, CD39, and CTLA-4, were significantly increased in both the tumor and peripheral CD8+ T cells. Thus, intratumoral AdV-tk injection into non-small-cell lung cancer (NSCLC) proved safe and feasible, and it effectively induced CD8+ T cell activation. These data provide a foundation for additional clinical trials of GMCI for lung cancer patients with potential benefit if combined with other immune therapies.

Outcomes After Tracheostomy in COVID-19 Patients.

OBJECTIVE: To determine the outcomes of patients undergoing tracheostomy for COVID-19 and of healthcare workers performing these procedures. BACKGROUND: Tracheostomy is often performed for prolonged endotracheal intubation in critically ill patients. However, in the context of COVID-19, tracheostomy placement pathways have been altered due to the poor prognosis of intubated patients and the risk of transmission to providers through this highly aerosolizing procedure. METHODS: A prospective single-system multi-center observational cohort study was performed on patients who underwent tracheostomy after acute respiratory failure secondary to COVID-19. RESULTS: Of the 53 patients who underwent tracheostomy, the average time from endotracheal intubation to tracheostomy was 19.7 days ±â€Š6.9 days. The most common indication for tracheostomy was acute respiratory distress syndrome, followed by failure to wean ventilation and post-extracorporeal membrane oxygenation decannulation. Thirty patients (56.6%) were liberated from the ventilator, 16 (30.2%) have been discharged alive, 7 (13.2%) have been decannulated, and 6 (11.3%) died. The average time from tracheostomy to ventilator liberation was 11.8 days ±â€Š6.9 days (range 2-32 days). Both open surgical and percutaneous dilational tracheostomy techniques were performed utilizing methods to mitigate aerosols. No healthcare worker transmissions resulted from performing the procedure. CONCLUSIONS: Alterations to tracheostomy practices and processes were successfully instituted. Following these steps, tracheostomy in COVID-19 intubated patients seems safe for both patients and healthcare workers performing the procedure.

Phase I Study of Lentiviral-Transduced Chimeric Antigen Receptor-Modified T Cells Recognizing Mesothelin in Advanced Solid Cancers.

This phase I study investigated the safety and activity of lentiviral-transduced chimeric antigen receptor (CAR)-modified autologous T cells redirected against mesothelin (CART-meso) in patients with malignant pleural mesothelioma, ovarian carcinoma, and pancreatic ductal adenocarcinoma. Fifteen patients with chemotherapy-refractory cancer (n = 5 per indication) were treated with a single CART-meso cell infusion. CART-meso cells were engineered by lentiviral transduction with a construct composed of the anti-mesothelin single-chain variable fragment derived from the mouse monoclonal antibody SS1 fused to intracellular signaling domains of 4-1BB and CD3zeta. Patients received 1-3 × 107 or 1-3 × 108 CART-meso cells/m2 with or without 1.5 g/m2 cyclophosphamide. Lentiviral-transduced CART-meso cells were well tolerated; one dose-limiting toxicity (grade 4, sepsis) occurred at 1-3 × 107/m2 CART-meso without cyclophosphamide. The best overall response was stable disease (11/15 patients). CART-meso cells expanded in the blood and reached peak levels by days 6-14 but persisted transiently. Cyclophosphamide pre-treatment enhanced CART-meso expansion but did not improve persistence beyond 28 days. CART-meso DNA was detected in 7/10 tumor biopsies. Human anti-chimeric antibodies (HACA) were detected in the blood of 8/14 patients. CART-meso cells were well tolerated and expanded in the blood of all patients but showed limited clinical activity. Studies evaluating a fully human anti-mesothelin CAR are ongoing.

Bidirectional transfer of Anelloviridae lineages between graft and host during lung transplantation.

Solid organ transplantation disrupts virus-host relationships, potentially resulting in viral transfer from donor to recipient, reactivation of latent viruses, and new viral infections. Viral transfer, colonization, and reactivation are typically monitored using assays for specific viruses, leaving the behavior of full viral populations (the "virome") understudied. Here we sought to investigate the temporal behavior of viruses from donor lungs and transplant recipients comprehensively. We interrogated the bronchoalveolar lavage and blood viromes during the peritransplant period and 6-16 months posttransplant in 13 donor-recipient pairs using shotgun metagenomic sequencing. Anelloviridae, ubiquitous human commensal viruses, were the most abundant human viruses identified. Herpesviruses, parvoviruses, polyomaviruses, and bacteriophages were also detected. Anelloviridae populations were complex, with some donor organs and hosts harboring multiple contemporaneous lineages. We identified transfer of Anelloviridae lineages from donor organ to recipient serum in 4 of 7 cases that could be queried, and immigration of lineages from recipient serum into the allograft in 6 of 10 such cases. Thus, metagenomic analyses revealed that viral populations move between graft and host in both directions, showing that organ transplantation involves implantation of both the allograft and commensal viral communities.

Malignant Mesothelioma: Has Anything Changed?

Malignant pleural mesothelioma is a rare cancer associated with asbestos exposure and portends a dismal prognosis. Its worldwide incidence has been increasing, and treatment options are currently suboptimal and noncurative. However, since the turn of the century, several encouraging steps have been made toward improving outcomes for mesothelioma patients. An increased understanding of disease pathophysiology has led to more accurate diagnosis and staging, and the establishment of the standard of care first-line pemetrexed/platin doublet chemotherapy regimen in 2003 initially revolutionized treatment. While significant debate remains regarding the preferred approach to surgical and radiation therapy in the context of multimodal therapy, recent breakthroughs in immunotherapy offer hope for another paradigm shift in the near future. This review will summarize the current clinical approach to diagnosis, staging, and treatment of malignant pleural mesothelioma.

Phase I Study of Intrapleural Gene-Mediated Cytotoxic Immunotherapy in Patients with Malignant Pleural Effusion.

Gene-mediated cytotoxic immunotherapy (GMCI) is an immune strategy implemented through local delivery of an adenovirus-based vector expressing the thymidine kinase gene (aglatimagene besadenovec, AdV-tk) followed by anti-herpetic prodrug valacyclovir. A phase I dose escalation trial of GMCI followed by chemotherapy was conducted in patients with malignant pleural effusion (MPE). AdV-tk was administered intrapleurally (IP) in three cohorts at a dose of 1 × 1012 to 1013 vector particles. Primary endpoint was safety; secondary endpoints included response rate, progression-free survival, and overall survival. Nineteen patients were enrolled: median age 67 years; 14 with malignant mesothelioma, 4 non-small-cell lung cancer (NSCLC), and 1 breast cancer. There were no dose limiting toxicities. All 3 patients in cohort 2 experienced transient cytokine release syndrome (CRS). Addition of celecoxib in cohort 3 reduced the incidence and severity of CRS (none > grade 2). Three patients are alive (23-33 months after GMCI), and 3 of 4 NSCLC patients had prolonged disease stabilization; one is alive 29 months after GMCI, 3.6 years after initial diagnosis. GMCI was safe and well tolerated in combination with chemotherapy in patients with MPE and showed encouraging response. Further studies are warranted to determine efficacy.

Intravenous delivery of a multi-mechanistic cancer-targeted oncolytic poxvirus in humans.

The efficacy and safety of biological molecules in cancer therapy, such as peptides and small interfering RNAs (siRNAs), could be markedly increased if high concentrations could be achieved and amplified selectively in tumour tissues versus normal tissues after intravenous administration. This has not been achievable so far in humans. We hypothesized that a poxvirus, which evolved for blood-borne systemic spread in mammals, could be engineered for cancer-selective replication and used as a vehicle for the intravenous delivery and expression of transgenes in tumours. JX-594 is an oncolytic poxvirus engineered for replication, transgene expression and amplification in cancer cells harbouring activation of the epidermal growth factor receptor (EGFR)/Ras pathway, followed by cell lysis and anticancer immunity. Here we show in a clinical trial that JX-594 selectively infects, replicates and expresses transgene products in cancer tissue after intravenous infusion, in a dose-related fashion. Normal tissues were not affected clinically. This platform technology opens up the possibility of multifunctional products that selectively express high concentrations of several complementary therapeutic and imaging molecules in metastatic solid tumours in humans.

Intra-procedural Bronchoscopy to Prevent Bronchial Compression During Pulmonary Artery Stent Angioplasty.

Stenosis of the pulmonary arteries frequently occurs during staged palliation of hypoplastic left heart syndrome and variants, often necessitating stent angioplasty. A complication of stent angioplasty is compression of the ipsilateral mainstem bronchus. Following such a case, we re-evaluated our approach to PA stent angioplasty in these patients. The incident case is described. A retrospective observational study of children and adults with superior (SCPC) and/or total cavopulmonary connection (TCPC) undergoing left pulmonary artery (LPA) stent angioplasty between January 1, 2005 and January 5, 2014 and subsequent chest CT was performed to assess the incidence of bronchial compression. The current strategy of employing bronchoscopy to assess bronchial compression during angioplasty is described with short-term results. Sixty-five children and adults underwent LPA stent angioplasty. Other than the incident case, none had symptomatic bronchial compression. Of the total study population, 12 % had subsequent CT, of which one subject had moderate bronchial compression. To date, seven subjects have undergone angioplasty of LPA stenosis and bronchoscopy. In one case, stent angioplasty was not performed because of baseline bronchial compression, exacerbated during angioplasty. In the rest of cases, mild-moderate compression was seen during angioplasty. Following stent angioplasty, the resultant compression was not worse than that seen on test angioplasty. Bronchial compression is a rare complication of stent angioplasty of the pulmonary arteries in children and adults with SCPC/TCPC. Angioplasty of the region of interest with procedural bronchoscopy can help to identify patients at risk of this complication.

Diagnostic yield of endobronchial ultrasound and virtual CT navigational bronchoscopy for biopsy of pulmonary nodules, mediastinal lymph nodes, and thoracic tumors in children.

OBJECTIVE: Endobronchial ultrasound-guided transbronchial biopsy and needle aspiration (EBUS-TBB/EBUS-TBNA) are first line investigative modalities for lung and mediastinal pathology in adults. We aimed to characterize and assess the diagnostic yield of EBUS and virtual CT navigation guided biopsies in children. STUDY DESIGN: This single center, retrospective cohort study included patients who underwent radial or linear EBUS procedures (+/- CT navigation) for biopsy of mediastinal lymph nodes, tumors, and pulmonary nodules. Demographic, procedural, and outcome were collected. RESULTS: Sixty procedures were performed in 56 patients aged 2-22 years of age between January 2015 and May 2023. The most common indications for biopsy were pulmonary nodules (45%) and hilar/mediastinal lymphadenopathy (33%). For cases in which a final diagnosis was ascertained by any means, the diagnostic yield for linear EBUS (mediastinal pathology) was 76% and the diagnostic yield from radial EBUS (pulmonary nodules and lung masses) was 85%. The most common diagnoses were infection (45%), malignancy (17%), and sarcoidosis (11%). Among patients in whom infection was the final diagnosis, a total of 31 pathogens were identified. Eighteen were identified on bronchoalveolar lavage and an additional 14 pathogens identified on EBUS-TBB, representing an increase of 77% (p < .005). The sensitivity, specificity, negative and positive predictive values for malignancy detection were 73%, 100%, 94%, and 100%, respectively. CONCLUSION: EBUS-TBB/TBNA is a safe and effective way to diagnose lung and mediastinal pathology in children. Pediatric interventional pulmonology is a growing field offering minimally-invasive diagnostic opportunities for children in whom more invasive procedures were previously the only option.

Microbiome Profiling Demonstrates Concordance of Endotracheal Tube Aspirates With Direct Lower Airway Sampling in Intubated Patients.

BACKGROUND: Endotracheal aspirates (ETAs) are widely used for microbiologic studies of the respiratory tract in intubated patients. However, they involve sampling through an established endotracheal tube using suction catheters, both of which can acquire biofilms that may confound results. RESEARCH QUESTION: Does standard clinical ETA in intubated patients accurately reflect the authentic lower airway bacterial microbiome? STUDY DESIGN AND METHODS: Comprehensive quantitative bacterial profiling using 16S rRNA V1-V2 gene sequencing was applied to compare bacterial populations captured by standard clinical ETA vs contemporaneous gold standard samples acquired directly from the lower airways through a freshly placed sterile tracheostomy tube. The study included 13 patients undergoing percutaneous tracheostomy following prolonged (median, 15 days) intubation. Metrics of bacterial composition, diversity, and relative quantification were applied to samples. RESULTS: Pre-tracheostomy ETAs closely resembled the gold standard immediate post-tracheostomy airway microbiomes in bacterial composition and community features of diversity and quantification. Endotracheal tube and suction catheter biofilms also resembled cognate ETA and fresh tracheostomy communities. INTERPRETATION: Unbiased molecular profiling shows that standard clinical ETA sampling has good concordance with the authentic lower airway microbiome in intubated patients.

Lung-enriched organisms and aberrant bacterial and fungal respiratory microbiota after lung transplant.

RATIONALE: Long-term survival after lung transplantation is limited by infectious complications and by bronchiolitis obliterans syndrome (BOS), a form of chronic rejection linked in part to microbial triggers. OBJECTIVES: To define microbial populations in the respiratory tract of transplant patients comprehensively using unbiased high-density sequencing. METHODS: Lung was sampled by bronchoalveolar lavage (BAL) and upper respiratory tract by oropharyngeal wash (OW). Bacterial 16S rDNA and fungal internal transcribed spacer sequencing was used to profile organisms present. Outlier analysis plots defining taxa enriched in lung relative to OW were used to identify bacteria enriched in lung against a background of oropharyngeal carryover. MEASUREMENTS AND MAIN RESULTS: Lung transplant recipients had higher bacterial burden in BAL than control subjects, frequent appearance of dominant organisms, greater distance between communities in BAL and OW indicating more distinct populations, and decreased respiratory tract microbial richness and diversity. Fungal populations were typically dominated by Candida in both sites or by Aspergillus in BAL but not OW. 16S outlier analysis identified lung-enriched taxa indicating bacteria replicating in the lower respiratory tract. In some cases this confirmed respiratory cultures but in others revealed enrichment by anaerobic organisms or mixed outgrowth of upper respiratory flora and provided quantitative data on relative abundances of bacteria found by culture. CONCLUSIONS: Respiratory tract microbial communities in lung transplant recipients differ in structure and composition from healthy subjects. Outlier analysis can identify specific bacteria replicating in lung. These findings provide novel approaches to address the relationship between microbial communities and transplant outcome and aid in assessing lung infections.

Diagnostic Yield of Cone-beam-Derived Augmented Fluoroscopy and Ultrathin Bronchoscopy Versus Conventional Navigational Bronchoscopy Techniques.

BACKGROUND: Pulmonary nodules suspicious for lung cancer are frequently diagnosed. Evaluating and optimizing the diagnostic yield of lung nodule biopsy is critical as innovation in bronchoscopy continues to progress. METHODS: This is a retrospective cohort study. Consecutive patients undergoing guided bronchoscopy for suspicious pulmonary nodule(s) between February 2020 and July 2021 were included. The cone-beam computed tomography (CBCT)+ radial endobronchial ultrasound (r-EBUS) group had their procedure using CBCT-derived augmented fluoroscopy along with r-EBUS. The CBCT+ ultrathin bronchoscope (UTB)+r-EBUS group had the same procedure but with the use of an ultrathin bronchoscope. The r-EBUS group underwent r-EBUS guidance without CBCT or augmented fluoroscopy. We used multivariable logistic regression to compare diagnostic yield, adjusting for confounding variables. RESULTS: A total of 116 patients were included. The median pulmonary lesion diameter was 19.5 mm (interquartile range, 15.0 to 27.5 mm), and 91 (78.4%) were in the peripheral half of the lung. Thirty patients (25.9%) underwent CBCT+UTB, 27 (23.3%) CBCT, and 59 (50.9%) r-EBUS alone with unadjusted diagnostic yields of 86.7%, 70.4%, and 42.4%, respectively ( P <0.001). The adjusted diagnostic yields were 85.0% (95% CI, 68.6% to 100%), 68.3% (95% CI, 50.1% to 86.6%), and 44.5% (95% CI, 31.0% to 58.0%), respectively. There was significantly more virtual navigational bronchoscopy use in the r-EBUS group (45.8%) compared with the CBCT+UTB (13.3%) and CBCT (18.5%) groups, respectively. CBCT procedures required dose area product radiation doses of 7602.5 µGym 2 . CONCLUSION: Compared with the r-EBUS group, CBCT + UTB + r-EBUS was associated with higher navigational success, fewer nondiagnostic biopsy results, and a higher diagnostic yield. CBCT procedures are associated with a considerable radiation dose.

The Performance of an Extended Next Generation Sequencing Panel Using Endobronchial Ultrasound-Guided Fine Needle Aspiration Samples in Non-Squamous Non-Small Cell Lung Cancer: A Pragmatic Study.

INTRODUCTION/BACKGROUND: Samples from endobronchial ultrasound-guided fine needle aspiration (EBUS-TBNA) are frequently used for next generation sequencing (NGS) in patients with non-small cell lung cancer (NSCLC) to look for genetic driver mutations. The objective of the current study was to evaluate the performance of extended NGS panels using EBUS-TBNA samples in a real-world setting and identify factors associated with the success of NGS. MATERIALS AND METHODS: This study included all patients who underwent EBUS and were diagnosed with non-squamous NSCLC with mediastinal metastasis from 2016 to 2019 at the University of Pennsylvania. We reviewed demographic information, imaging studies, procedure reports, pathology and NGS reports. Logistic regression was used to analyze factors associated with the success of NGS panels. RESULTS: The success rates of NGS using EBUS-TBNA samples were 92.5%, and 91.5% for DNA and RNA NGS panels respectively. Samples from higher N stage (N2 and N3 lymph nodes) and with higher tumor cellularity (>25%) resulted in higher success rate for DNA NGS. The effect of tumor cellularity remained borderline significant after entering multivariable logistic regression. The short-axis diameter of the sampled lymph node on CT scan, FDG-avidity on PET CT and >3 EBUS passes per lymph node during the procedure were not associated with NGS success. CONCLUSION: Both DNA and RNA extended-panel NGS had high performance using EBUS-TBNA samples. Sampling more advanced nodal stations and obtaining samples with higher tumor cellularity were associated with higher success rate of DNA NGS. Other imaging or procedural factors did not affect NGS performance.

Clinical Outcomes Associated With Pembrolizumab Monotherapy Among Adults With Diffuse Malignant Peritoneal Mesothelioma.

Importance: Diffuse malignant peritoneal mesothelioma (DMPM) represents a rare and clinically distinct entity among malignant mesotheliomas. Pembrolizumab has activity in diffuse pleural mesothelioma but limited data are available for DMPM; thus, DMPM-specific outcome data are needed. Objective: To evaluate outcomes after the initiation of pembrolizumab monotherapy in the treatment of adults with DMPM. Design, Setting, and Participants: This retrospective cohort study was conducted in 2 tertiary care academic cancer centers (University of Pennsylvania Hospital Abramson Cancer Center and Memorial Sloan Kettering Cancer Center). All patients with DMPM treated between January 1, 2015, and September 1, 2019, were retrospectively identified and followed until January 1, 2021. Statistical analysis was performed between September 2021 and February 2022. Exposures: Pembrolizumab (200 mg or 2 mg/kg every 21 days). Main Outcomes and Measures: Median progression-free survival (PFS) and median overall survival (OS) were assessed using Kaplan-Meier estimates. The best overall response was determined using RECIST (Response Evaluation Criteria in Solid Tumors) criteria, version 1.1. The association of disease characteristics with partial response was evaluated using the Fisher exact test. Results: This study included 24 patients with DMPM who received pembrolizumab monotherapy. Patients had a median age of 62 years (IQR, 52.4-70.6 years); 14 (58.3%) were women, 18 (75.0%) had epithelioid histology, and most (19 [79.2%]) were White. A total of 23 patients (95.8%) received systemic chemotherapy prior to pembrolizumab, and the median number of lines of prior therapy was 2 (range, 0-6 lines). Of the 17 patients who underwent programmed death ligand 1 (PD-L1) testing, 6 (35.3%) had positive tumor PD-L1 expression (range, 1.0%-80.0%). Of the 19 evaluable patients, 4 (21.0%) had a partial response (overall response rate, 21.1% [95% CI, 6.1%-46.6%]), 10 (52.6%) had stable disease, and 5 (26.3%) had progressive disease (5 of 24 patients [20.8%] were lost to follow-up). There was no association between a partial response and the presence of a BAP1 alteration, PD-L1 positivity, or nonepithelioid histology. With a median follow-up of 29.2 (95% CI, 19.3 to not available [NA]) months, the median PFS was 4.9 (95% CI, 2.8-13.3) months and the median OS was 20.9 (95% CI, 10.0 to NA) months from pembrolizumab initiation. Three patients (12.5%) experienced PFS of more than 2 years. Among patients with nonepithelioid vs epithelioid histology, there was a numeric advantage in median PFS (11.5 [95% CI, 2.8 to NA] vs 4.0 [95% CI, 2.8-8.8] months) and median OS (31.8 [95% CI, 8.3 to NA] vs 17.5 [95% CI, 10.0 to NA] months); however, this did not reach statistical significance. Conclusions and Relevance: The results of this retrospective dual-center cohort study of patients with DMPM suggest that pembrolizumab had clinical activity regardless of PD-L1 status or histology, although patients with nonepithelioid histology may have experienced additional clinical benefit. The partial response rate of 21.0% and median OS of 20.9 months in this cohort with 75.0% epithelioid histology warrants further investigation to identify those most likely to respond to immunotherapy.

Novel intrapleural therapies for malignant diseases.

Pleural malignancies, either primary or metastatic, are common and problematic clinical issues in thoracic oncology and pulmonary medicine. Malignant pleural mesothelioma and metastatic pleural effusions often present late in the course of a disease and have a dramatic impact on the patient's quality of life and survival. Novel approaches to manage mesothelioma and malignant pleural effusions are desperately needed and the pleural space provides a unique platform as an easily accessible body cavity for developing and assessing these treatments and their responses. In this review, we discuss the unique intrapleural chemotherapeutic, immunotherapeutic and genetic treatments that have been investigated, as well as those under current clinical development. While responses have been demonstrated to variable degrees with all these approaches, an integrated multimodality approach incorporating these methods with other anti-neoplastic interventions ultimately will ensure the best responses and patient outcomes.

Topographical continuity of bacterial populations in the healthy human respiratory tract.

RATIONALE: Defining the biogeography of bacterial populations in human body habitats is a high priority for understanding microbial-host relationships in health and disease. The healthy lung was traditionally considered sterile, but this notion has been challenged by emerging molecular approaches that enable comprehensive examination of microbial communities. However, studies of the lung are challenging due to difficulties in working with low biomass samples. OBJECTIVES: Our goal was to use molecular methods to define the bacterial microbiota present in the lungs of healthy individuals and assess its relationship to upper airway populations. METHODS: We sampled respiratory flora intensively at multiple sites in six healthy individuals. The upper tract was sampled by oral wash and oro-/nasopharyngeal swabs. Two bronchoscopes were used to collect samples up to the glottis, followed by serial bronchoalveolar lavage and lower airway protected brush. Bacterial abundance and composition were analyzed by 16S rDNA Q-PCR and deep sequencing. MEASUREMENTS AND MAIN RESULTS: Bacterial communities from the lung displayed composition indistinguishable from the upper airways, but were 2 to 4 logs lower in biomass. Lung-specific sequences were rare and not shared among individuals. There was no unique lung microbiome. CONCLUSIONS: In contrast to other organ systems, the respiratory tract harbors a homogenous microbiota that decreases in biomass from upper to lower tract. The healthy lung does not contain a consistent distinct microbiome, but instead contains low levels of bacterial sequences largely indistinguishable from upper respiratory flora. These findings establish baseline data for healthy subjects and sampling approaches for sequence-based analysis of diseases.