Treatment Characteristics and Real-World Progression-Free Survival in Patients With Unresectable Stage III NSCLC Who Received Durvalumab After Chemoradiotherapy: Findings From the PACIFIC-R Study.

INTRODUCTION: The phase 3 PACIFIC trial established consolidation therapy with durvalumab as standard of care for patients with unresectable, stage III NSCLC and no disease progression after definitive chemoradiotherapy (CRT). The observational PACIFIC-R study assesses the real-world effectiveness of durvalumab in patients from an early access program. Here, we report treatment characteristics and a preplanned analysis of real-world progression-free survival (rwPFS). METHODS: PACIFIC-R (NCT03798535) is an ongoing, international, retrospective study of patients who started durvalumab (intravenously; 10 mg/kg every 2 wk) within an early access program between September 2017 and December 2018. The primary end points are investigator-assessed rwPFS and overall survival (analyzed by Kaplan-Meier method). RESULTS: As of November 30, 2020, the full analysis set comprised 1399 patients from 11 countries (median follow-up duration, 23.5 mo). Patients received durvalumab for a median of 11.0 months. Median rwPFS was 21.7 months (95% confidence interval: 19.1-24.5). RwPFS was numerically longer among patients who received concurrent versus sequential CRT (median, 23.7 versus 19.3 mo) and among patients with programmed cell death-ligand 1 expression greater than or equal to 1% versus less than 1% (22.4 versus 15.6 mo). Overall, 16.5% of the patients had adverse events leading to treatment discontinuation; 9.5% of all patients discontinued because of pneumonitis or interstitial lung disease. CONCLUSIONS: Consolidation durvalumab after definitive CRT was well tolerated and effective in this large, real-world cohort study of patients with unresectable, stage III NSCLC. As expected, rwPFS was longer among patients who received concurrent versus sequential CRT and patients with higher programmed cell death-ligand 1 expression. Nevertheless, favorable rwPFS outcomes were observed regardless of these factors.

Using a peptide-based mass spectrometry approach to quantitate proteolysis of an intact heterogeneous procollagen substrate by BMP1 for antagonistic antibody screening.

Proteases are critical proteins involved in cleaving substrates that may impact biological pathways, cellular processes, or disease progression. In the biopharmaceutical industry, modulating the levels of protease activity is an important strategy for mitigating many types of diseases. While a variety of analytical tools exist for characterizing substrate cleavages, in vitro functional screening for antibody inhibitors of protease activity using physiologically relevant intact protein substrates remains challenging. In addition, detecting such large protein substrates with high heterogeneity using high-throughput mass spectrometry screening has rarely been reported in the literature with concerns for assay robustness and sensitivity. In this study, we established a peptide-based in vitro functional screening assay for antibody inhibitors of mouse bone morphogenic protein 1 (mBMP1) metalloprotease using a heterogeneous recombinant 66-kDa mouse Procollagen I alpha 1 chain (mProcollagen) substrate. We compared several analytical tools including capillary gel electrophoresis Western blot (CE-Western blot), as well as both intact protein and peptide-based mass spectrometry (MS) to quantitate the mBMP1 proteolytic activity and its inhibition by antibodies using this heterogeneous mProcollagen substrate. We concluded that the peptide-based mass spectrometry screening assay was the most suitable approach in terms of throughput, sensitivity, and assay robustness. We then optimized our mBMP1 proteolysis reaction after characterizing the enzyme kinetics using the peptide-based MS assay. This assay resulted in Z' values ranging from 0.6 to 0.8 from the screening campaign. Among over 1200 antibodies screened, IC50 characterization was performed on the top candidate hits, which showed partial or complete inhibitory activities against mBMP1.

CAR T Cell Locomotion in Solid Tumor Microenvironment.

The promising outcomes of chimeric antigen receptor (CAR) T cell therapy in hematologic malignancies potentiates its capability in the fight against many cancers. Nevertheless, this immunotherapy modality needs significant improvements for the treatment of solid tumors. Researchers have incrementally identified limitations and constantly pursued better CAR designs. However, even if CAR T cells are armed with optimal killer functions, they must overcome and survive suppressive barriers imposed by the tumor microenvironment (TME). In this review, we will discuss in detail the important role of TME in CAR T cell trafficking and how the intrinsic barriers contribute to an immunosuppressive phenotype and cancer progression. It is of critical importance that preclinical models can closely recapitulate the in vivo TME to better predict CAR T activity. Animal models have contributed immensely to our understanding of human diseases, but the intensive care for the animals and unreliable representation of human biology suggest in vivo models cannot be the sole approach to CAR T cell therapy. On the other hand, in vitro models for CAR T cytotoxic assessment offer valuable insights to mechanistic studies at the single cell level, but they often lack in vivo complexities, inter-individual heterogeneity, or physiologically relevant spatial dimension. Understanding the advantages and limitations of preclinical models and their applications would enable more reliable prediction of better clinical outcomes.

A homogeneous high-DAR antibody-drug conjugate platform combining THIOMAB antibodies and XTEN polypeptides.

The antibody-drug conjugate (ADC) is a well-validated modality for the cell-specific delivery of small molecules with impact expanding rapidly beyond their originally-intended purpose of treating cancer. However, antibody-mediated delivery (AMD) remains inefficient, limiting its applicability to targeting highly potent payloads to cells with high antigen expression. Maximizing the number of payloads delivered per antibody is one key way in which delivery efficiency can be improved, although this has been challenging to carry out; with few exceptions, increasing the drug-to-antibody ratio (DAR) above ∼4 typically destroys the biophysical properties and in vivo efficacy for ADCs. Herein, we describe the development of a novel bioconjugation platform combining cysteine-engineered (THIOMAB) antibodies and recombinant XTEN polypeptides for the unprecedented generation of homogeneous, stable "TXCs" with DAR of up to 18. Across three different bioactive payloads, we demonstrated improved AMD to tumors and Staphylococcus aureus bacteria for high-DAR TXCs relative to conventional low-DAR ADCs.

Treatment Patterns in Patients with Locally Advanced or Metastatic Non-Small-Cell Lung Cancer Treated with Epidermal Growth Factor Receptor-Tyrosine Kinase Inhibitors: Analysis of US Insurance Claims Databases.

BACKGROUND: Most patients with epidermal growth factor receptor mutation-positive (EGFRm) non-small-cell lung cancer (NSCLC) acquire resistance to first-line (1L) first- or second-generation (1G/2G) EGFR-TKIs; therefore, it is important to optimize 1L treatment to improve patient outcomes. OBJECTIVE: To retrospectively examine treatment patterns in locally advanced/metastatic NSCLC using MarketScan® Commercial and Medicare Supplemental Databases (all US census regions). PATIENTS AND METHODS: Adults with a lung cancer diagnosis code between 1 January 2015-31 March 2018 were analyzed from diagnosis (index) through a variable-length follow-up. Patients had ≥ 1 pharmacy claim for 1G/2G EGFR-TKIs on or within 60 days post-index. Data were stratified by presence or absence of central nervous system (CNS) metastases (30 days pre-index through study end). RESULTS: 578 patients were included (median age 63 years, 64% female). Median follow-up was 13.5 months. The most frequently prescribed 1L EGFR-TKI was erlotinib (414/578, 72%). Median time to 1L treatment discontinuation was 8.2 (95% confidence interval (CI) 6.9, 9.0) months in patients diagnosed with CNS metastases at any time, and 7.7 (95% CI 6.9, 8.9) months in patients without CNS metastases. 270/578 patients (47%) discontinued 1L EGFR-TKIs; 209/270 (77%) initiated second-line (2L) therapy, most frequently osimertinib (96/209, 46%). CONCLUSIONS: In an analysis of US claims data, nearly half of patients discontinued 1L EGFR-TKIs, and 46% who initiated 2L received osimertinib. As nearly a quarter of patients who discontinued 1L EGFR-TKIs did not receive 2L treatment, this study highlights the need for optimal 1L treatment in EGFRm locally advanced/metastatic NSCLC.

DUART: durvalumab after radiotherapy in patients with unresectable, stage III NSCLC who are ineligible for chemotherapy.

Consolidation durvalumab is standard of care in patients with unresectable, stage III non-small-cell lung cancer (NSCLC) without disease progression following chemoradiotherapy (the 'PACIFIC regimen'). However, many patients with poor performance status, older age or comorbidities may be ineligible for chemotherapy due to expected high toxicity. These patients typically receive radiotherapy alone, with poor survival outcomes. Based on the PACIFIC trial data, and the strong biological rationale for combining radiotherapy with anti-programmed cell death ligand-1 therapy, durvalumab following radiotherapy could provide additional survival benefit versus radiotherapy alone. Here, we describe the DUART trial, a Phase II, open-label, single-arm study assessing the safety and tolerability of durvalumab following radiotherapy in patients with unresectable, stage III NSCLC who are ineligible for chemotherapy (ClinicalTrials.gov Identifier: NCT04249362).

Lay abstract The current standard treatment for patients with stage III non-small-cell lung cancer whose cancer cannot be removed by surgery is chemotherapy plus radiotherapy; if their disease gets no worse after this, patients also receive durvalumab ­ altogether this is known as the 'PACIFIC regimen'. However, some patients who are older or who have existing health conditions cannot tolerate chemotherapy, so instead of the PACIFIC regimen they receive radiotherapy only. The DUART study described here is an ongoing, Phase II clinical trial looking at the safety and tolerability of durvalumab after radiotherapy in patients with stage III non-small-cell lung cancer who are unsuitable for chemotherapy and whose cancer cannot be removed by surgery. Clinical Trial Registration: NCT04249362.

European and US Real-World Treatment Patterns in Patients with Epidermal Growth Factor Receptor Mutation-Positive Non-Small Cell Lung Cancer: A Retrospective Medical Record Review.

BACKGROUND: Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) are the preferred first-line (1L) therapy for EGFR mutation-positive (EGFRm) advanced/metastatic non-small cell lung cancer (NSCLC). OBJECTIVE: Our objective was to describe real-world treatment patterns and T790M testing practices in patients with 1L disease progression (Europe/USA) following treatment with first- or second-generation EGFR-TKIs. METHODS: This was a retrospective, non-interventional medical record review of patients with EGFRm locally advanced/metastatic NSCLC from routine clinical practice (EGFR-TKI initiation: 1 January 2015 to 31 December 2017; follow-up: last available medical record). Endpoints were demographic/clinical characteristics, incidence of central nervous system (CNS) metastases/leptomeningeal disease, second-line (2L) treatment, T790M mutation testing, and osimertinib treatment prevalence. RESULTS: Among 469 patients, 73% (n = 341/469) progressed on 1L EGFR-TKI treatment. Of those who progressed, 74% (n = 252/341) were tested for T790M, with 50% (n = 126/252) testing positive; 75% (n = 94/126) of T790M-positive patients received osimertinib (mostly 2L). Of the patients with progression, 24% (n = 83/341) did not receive 2L treatment, and 88% (n = 73/83) of these patients died. At diagnosis of advanced disease, 9% of patients (n = 41) had CNS metastases; at EGFR-TKI initiation, 14% of patients (n = 68) had CNS metastases. Over the study period, 11% of patients (n = 42) developed CNS metastases not detected at NSCLC diagnosis. CONCLUSIONS: Rates of resistance mutation testing and subsequent utilization of recommended 2L therapies could be improved. As more targeted therapies are developed, it will be crucial to improve the molecular testing rates to ensure patients receive appropriate, effective, and timely treatment.

Ligated aluminum cluster anions, LAln- (n = 1-14, L = N[Si(Me)3]2).

A wide range of low oxidation state aluminum-containing cluster anions, LAln- (n = 1-14, L = N[Si(Me)3]2), were produced via reactions between aluminum cluster anions and hexamethyldisilazane (HMDS). These clusters were identified by mass spectrometry, with a few of them (n = 4, 6, and 7) further characterized by a synergy of anion photoelectron spectroscopy and density functional theory (DFT) based calculations. As compared to a previously reported method which reacts anionic aluminum hydrides with ligands, the direct reactions between aluminum cluster anions and ligands promise a more general synthetic scheme for preparing low oxidation state, ligated aluminum clusters over a large size range. Computations revealed structures in which a methyl-group of the ligand migrated onto the surface of the metal cluster, thereby resulting in "two metal-atom" insertion between Si-CH3 bond.

Antibody-Mediated Delivery of Chimeric BRD4 Degraders. Part 2: Improvement of In Vitro Antiproliferation Activity and In Vivo Antitumor Efficacy.

Heterobifunctional compounds that direct the ubiquitination of intracellular proteins in a targeted manner via co-opted ubiquitin ligases have enormous potential to transform the field of medicinal chemistry. These chimeric molecules, often termed proteolysis-targeting chimeras (PROTACs) in the chemical literature, enable the controlled degradation of specific proteins via their direction to the cellular proteasome. In this report, we describe the second phase of our research focused on exploring antibody-drug conjugates (ADCs), which incorporate BRD4-targeting chimeric degrader entities. We employ a new BRD4-binding fragment in the construction of the chimeric ADC payloads that is significantly more potent than the corresponding entity utilized in our initial studies. The resulting BRD4-degrader antibody conjugates exhibit potent and antigen-dependent BRD4 degradation and antiproliferation activities in cell-based experiments. Multiple ADCs bearing chimeric BRD4-degrader payloads also exhibit strong, antigen-dependent antitumor efficacy in mouse xenograft assessments that employ several different tumor models.

Topoisomerase Inhibitors Addressing Fluoroquinolone Resistance in Gram-Negative Bacteria.

Since their discovery over 5 decades ago, quinolone antibiotics have found enormous success as broad spectrum agents that exert their activity through dual inhibition of bacterial DNA gyrase and topoisomerase IV. Increasing rates of resistance, driven largely by target-based mutations in the GyrA/ParC quinolone resistance determining region, have eroded the utility and threaten the future use of this vital class of antibiotics. Herein we describe the discovery and optimization of a series of 4-(aminomethyl)quinolin-2(1H)-ones, exemplified by 34, that inhibit bacterial DNA gyrase and topoisomerase IV and display potent activity against ciprofloxacin-resistant Gram-negative pathogens. X-ray crystallography reveals that 34 occupies the classical quinolone binding site in the topoisomerase IV-DNA cleavage complex but does not form significant contacts with residues in the quinolone resistance determining region.

Adverse events in women switching from olaparib capsules to tablets: retrospective observational study of US claims data.

Aim: Describe rates of prespecified adverse events in patients who switched from olaparib capsules to tablets. Patients & methods: Retrospective, observational cohort analysis using self-controlled, pre-post design. Data on patients with ovarian cancer who switched from olaparib capsules to tablets between January 2015 and February 2019 were obtained from a US claims database. Results: Among all patients (n = 48), proportion with any prespecified adverse event was 45.8% (95% confidence interval: 31.4-60.8) during initial 90 days' capsule use and 35.4% (22.2-50.5) during initial 90 days' tablets use; difference -10.4% (-28.8-9.0). Conclusion: Switching from olaparib capsules to tablets was manageable with no evidence of increased toxicity. This real-world study supports the manageable tolerability of olaparib in women with ovarian cancer.

Microbial Signatures and Innate Immune Gene Expression in Lamina Propria Phagocytes of Inflammatory Bowel Disease Patients.

BACKGROUND & AIMS: The interaction between intestinal microbiota and the immune system plays a vital role in inflammatory bowel disease (IBD). Although numerous deep-sequencing studies have suggested dysbiosis in IBD, identifying specific bacteria from the stool or mucosa that are responsible for disease susceptibility or severity has remained a challenge. Lamina propria phagocytes ideally are localized to interact with bacteria that are in close proximity to, or have invaded, the tissue. Thus, we examined the microbial populations associated with the lamina propria phagocytes in 20 Crohn's disease and 12 ulcerative colitis patients. Specifically, we aimed to address whether the phagocyte-associated microbiota differed from the mucosa-associated microbiota and whether this varied based on IBD type or the state of inflammation. METHODS: 16S ribosomal RNA gene sequencing and innate immune gene expression profiling was done on CD11b+ lamina propria phagocytes isolated from the biopsies obtained from IBD patients. RESULTS: Phagocyte-associated microbiota was enriched in bacterial species belonging to phylum Proteobacteria, whereas species belonging to phylum Bacteroidetes were enriched in the mucosal microbiota of IBD patients. Disease type was the most influential factor in driving differences in the microbiota of both the mucosa and the lamina propria phagocytes, irrespective of inflammation state o`r anatomic location. Crohn's disease and ulcerative colitis specimens showed similar patterns of increased inflammatory gene expression in phagocytes isolated from inflamed areas compared with those isolated from uninflamed regions. CONCLUSIONS: This pilot study shows the feasibility of using lamina propria phagocytes to characterize the microbiota in IBD patients. The approach used in this study can narrow the spectrum of potentially dysbiotic bacterial populations and clinically relevant gene expression signatures in IBD patients.

Low oxidation state aluminum-containing cluster anions: Cp(∗)AlnH(-), n = 1-3.

Three new, low oxidation state, aluminum-containing cluster anions, Cp*AlnH(-), n = 1-3, were prepared via reactions between aluminum hydride cluster anions, AlnHm (-), and Cp*H ligands. These were characterized by mass spectrometry, anion photoelectron spectroscopy, and density functional theory based calculations. Agreement between the experimentally and theoretically determined vertical detachment energies and adiabatic detachment energies validated the computed geometrical structures. Reactions between aluminum hydride cluster anions and ligands provide a new avenue for discovering low oxidation state, ligated aluminum clusters.

Boston type 1 keratoprosthesis combined with silicone oil for treatment of hypotony in prephthisical eyes.

PURPOSE: To present the outcomes of Boston type I keratoprosthesis (KPro) implantation in combination with pars plana vitrectomy (PPV) and silicone oil for the treatment of hypotony in prephthisical eyes. METHODS: Interventional case series. Thirteen eyes of 13 patients underwent Boston type I KPro implantation, pars plana vitrectomy, and silicone oil placement. Concurrent retinal detachment repair, membrane peel, or intraocular lens explantation were performed if necessary. Inclusion criteria for surgery were eyes with visual acuity worse than 20/400, previous failed penetrating keratoplasty, corneal opacification, visually significant or worsening hypotony, and visual acuity 20/200 or worse in the fellow eye. Outcome measures included Snellen best-corrected visual acuity, anatomic retinal attachment, and complications. RESULTS: At the final follow-up (mean, 24 months; range, 5-66 months), visual acuity was improved in 10 of 13 eyes (77%), stable in 2 of 13 eyes (15%), and decreased in 1 of 13 eyes (8%). All eyes had attached retina with no progression to phthisis bulbi. No intraoperative complications occurred. Postoperative complications included retroprosthetic membrane (7 of 13), KPro melt (1 of 13), KPro leak (1 of 13), KPro infection (1 of 13), vitreous hemorrhage (1 of 13), and retinal detachment (1 of 13). CONCLUSIONS: Boston type I KPro implantation in combination with pars plana vitrectomy and intraocular silicone oil fill can improve vision in most prephthisical eyes with hypotony. Structural findings can also improve.

Unfolding of class A amphipathic peptides on a lipid surface.

The folding of polypeptides associated with biomembranes is a ubiquitous phenomenon, yet the thermodynamics underlying the process are poorly understood. In the present work we examine the unfolding of a series of alpha-helical amphipathic membrane-associated peptides using guanidine hydrochloride as a denaturant. The peptides are based on the class A amphipathic helix motif, and each contains a single tryptophan at sequence position 2, 3, 7, 12, or 14. The isothermal unfolding process was monitored by circular dichroism ellipticity at 222 nm to monitor changes in the helical structure of the peptide. Tryptophan fluorescence was used to probe the local changes in the environment about the indole fluorophore. The unfolding curves generated from the two experimental techniques for each peptide-lipid complex were non-coincidental, suggesting the presence of stable intermediate(s) in the unfolding. A three-state model could adequately account for the data and yielded parameters which were consistent with the presence of a partially folded intermediate structure which (i) is closer in Gibb's free energy to the folded state than the unfolded state and (ii) retains much of the interfacial and amphipathic character of the folded state. Denaturant-induced peptide dissociation from the peptide-lipid complexes was found to be negligible as confirmed by size exclusion chromatography. The results are compared with related thermodynamic data and discussed in terms of current models of peptide folding at membrane interfaces.

Site-specific tryptophan fluorescence spectroscopy as a probe of membrane peptide structure and dynamics.

The fluorescence from tryptophan contains valuable information about the environment local to the indole side-chain. This environment sensitivity coupled with the ability to synthetically or genetically incorporate a single tryptophan residue at specific sites in a polypeptide sequence has provided the membrane biophysicist with powerful tools for examining the structure and dynamics of membrane peptides and proteins. Here we briefly review the use of site-specific tryptophan fluorescence spectroscopy to probe aspects of peptide orientation, structure, and dynamics in lipid bilayers, focusing on recent developments in the literature.

The central domain of Escherichia coli TyrR is responsible for hexamerization associated with tyrosine-mediated repression of gene expression.

TyrR from Escherichia coli regulates the expression of genes for aromatic amino acid uptake and biosynthesis. Its central ATP-hydrolyzing domain is similar to conserved domains of bacterial regulatory proteins that interact with RNA polymerase holoenzyme associated with the alternative sigma factor, sigma(54). It is also related to the common module of the AAA+ superfamily of proteins that is involved in a wide range of cellular activities. We expressed and purified two TyrR central domain polypeptides. The fragment comprising residues 188-467, called TyrR-(188-467), was soluble and stable, in contrast to that corresponding to the conserved core from residues 193 to 433. TyrR-(188-467) bound ATP and rhodamine-ATP with association constants 2- to 5-fold lower than TyrR and hydrolyzed ATP at five times the rate of TyrR. In contrast to TyrR, which is predominantly dimeric at protein concentrations less than 10 microm in the absence of ligands, or in the presence of ATP or tyrosine alone, TyrR-(188-467) is a monomer, even at high protein concentrations. Tyrosine in the presence of ATP or ATPgammaS promotes the oligomerization of TyrR-(188-467) to a hexamer. Tyrosine-dependent repression of gene transcription by TyrR therefore depends on ligand binding and hexamerization determinants located in the central domain polypeptide TyrR-(188-467).

Patient-specific factors affecting patient-controlled analgesia dosing.

A study was conducted to evaluate the effect of characteristics patients' gender, age, weight, height, and body surface area, as well as the concurrent or recent use of opioids, ethanol and tobacco, on opioid dose requirements during administration of patient-controlled analgesia (PCA). Data were collected retrospectively from the medical records of 150 patients who underwent open cholecystectomies during an 18 month period at one institution. Demonstrable inter-patient variability in patterns of PCA use was observed. The results of the study demonstrate that during the first 48 hours of PCA therapy, patient age, height, weight, body surface area, gender, smoking, alcohol use, and preoperative opioid use may have significant influence on opioid analgesic use (p < 0.05). The data support the hypothesis that patient-specific factors may contribute to the variability observed in patients' PCA analgesic dose requirements, and these factors should be considered when selecting a proper demand (bolus) dose for PCA therapy.