Tolerability and antitumor activity of cemiplimab, a human monoclonal anti-PD-1, as monotherapy in patients with pretreated non-small cell lung cancer (NSCLC): Data from the Phase 1 NSCLC expansion cohort.

OBJECTIVES: Blockade of programmed cell death-1 (PD-1) and its ligand (PD-L1) has transformed the treatment of NSCLC. In a first-in-human, Phase 1, dose escalation and cohort expansion study, cemiplimab, a monoclonal antibody directed against PD-1, was evaluated for the treatment of patients with advanced solid tumors (NCT02383212). Here, we report results in patients with advanced NSCLC from the dose expansion cohort. MATERIALS AND METHODS: Immune-checkpoint inhibitor naive patients with advanced NSCLC (stage III/IV), irrespective of PD-L1 status, who had progressed after, or were refractory to first- or later-line therapy were enrolled and received cemiplimab 200 mg every 2 weeks intravenously for up to 48 weeks. Primary study objectives were to assess safety and tolerability, and to evaluate clinical activity of cemiplimab. RESULTS: Twenty patients with NSCLC were enrolled. Median age was 64.0 years (range: 50-82); 65.0 % were male; 80.0 % had an ECOG performance status of 1; 60.0 % had a histology of adenocarcinoma. Median number of prior lines of systemic therapy was 2 (range: 1-4). Median duration of follow-up was 7.0 months (range: 1.0-18.2). All patients experienced ≥1 treatment-emergent adverse event (TEAE) of any grade. Most common TEAEs were arthralgia, asthenia, cough, and dyspnea (each 4/20; 20.0 %). Grade ≥3 TEAEs occurred in 60.0 % (12/20) of patients. Of patients with measurable disease per independent central review (ICR), five had partial response (PR), four had stable disease (SD) and 10 had progressive disease. Objective response rate (ORR; complete response + PR) was 25.0 % (95 % CI: 8.7-49.1 %). Duration of response exceeded 8 months in four of the five responding patients at the time of data cut-off (April 30, 2019). The disease control rate per ICR (ORR + SD) was 50.0 % (95 % CI: 27.2-72.8 %). CONCLUSION: Cemiplimab showed an acceptable safety profile and demonstrated antitumor activity in pretreated patients with NSCLC.

Immunogenic membrane-associated proteins of Mycobacterium tuberculosis revealed by proteomics.

Membrane-associated proteins of Mycobacterium tuberculosis offer a challenge, as well as an opportunity, in the quest for better therapeutic and prophylactic interventions against tuberculosis. The authors have previously reported that extraction with the detergent Triton X-114 (TX-114) is a useful step in proteomic analysis of mycobacterial cell membranes, and detergent-soluble membrane proteins of mycobacteria are potent stimulators of human T cells. In this study 1-D and 2-D gel electrophoresis-based protocols were used for the analysis of proteins in the TX-114 extract of M. tuberculosis membranes. Peptide mass mapping (using MALDI-TOF-MS, matrix assisted laser desorption/ionization time of flight mass spectrometry) of 116 samples led to the identification of 105 proteins, 9 of which were new to the M. tuberculosis proteome. Functional orthologues of 73 of these proteins were also present in Mycobacterium leprae, suggesting their relative importance. Bioinformatics predicted that as many as 73% of the proteins had a hydrophobic disposition. 1-D gel electrophoresis revealed more hydrophobic/transmembrane and basic proteins than 2-D gel electrophoresis. Identified proteins fell into the following major categories: protein synthesis, cell wall biogenesis/architecture and conserved hypotheticals/unknowns. To identify immunodominant proteins of the detergent phase (DP), 14 low-molecular-mass fractions prepared by continuous-elution gel electrophoresis were subjected to T cell activation assays using blood samples from BCG-vaccinated healthy donors from a tuberculosis endemic area. Analysis of the responses (cell proliferation and IFN-gamma production) showed that the immunodominance of certain DP fractions was most probably due to ribosomal proteins, which is consistent with both their specificity for mycobacteria and their abundance. Other membrane-associated proteins, including transmembrane proteins/lipoproteins and ESAT-6, did not appear to contribute significantly to the observed T cell responses.

Proteome analysis of the plasma membrane of Mycobacterium tuberculosis.

The plasma membrane of Mycobacterium tuberculosis is likely to contain proteins that could serve as novel drug targets, diagnostic probes or even components of a vaccine against tuberculosis. With this in mind, we have undertaken proteome analysis of the membrane of M. tuberculosis H37Rv. Isolated membrane vesicles were extracted with either a detergent (Triton X114) or an alkaline buffer (carbonate) following two of the protocols recommended for membrane protein enrichment. Proteins were resolved by 2D-GE using immobilized pH gradient (IPG) strips, and identified by peptide mass mapping utilizing the M. tuberculosis genome database. The two extraction procedures yielded patterns with minimal overlap. Only two proteins, both HSPs, showed a common presence. MALDI-MS analysis of 61 spots led to the identification of 32 proteins, 17 of which were new to the M. tuberculosis proteome database. We classified 19 of the identified proteins as 'membrane-associated'; 14 of these were further classified as 'membrane-bound', three of which were lipoproteins. The remaining proteins included four heat-shock proteins and several enzymes involved in energy or lipid metabolism. Extraction with Triton X114 was found to be more effective than carbonate for detecting 'putative' M. tuberculosis membrane proteins. The protocol was also found to be suitable for comparing BCG and M. tuberculosis membranes, identifying ESAT-6 as being expressed selectively in M. tuberculosis. While this study demonstrates for the first time some of the membrane proteins of M. tuberculosis, it also underscores the problems associated with proteomic analysis of a complex membrane such as that of a mycobacterium.

An automated annotation tool for genomic DNA sequences using GeneScan and BLAST.

Genomic sequence data are often available well before the annotated sequence is published. We present a method for analysis of genomic DNA to identify coding sequences using the GeneScan algorithm and characterize these resultant sequences by BLAST. The routines are used to develop a system for automated annotation of genome DNA sequences.