Immuno-PET identifies the myeloid compartment as a key contributor to the outcome of the antitumor response under PD-1 blockade.

Immunotherapy using checkpoint-blocking antibodies against PD-1 has produced impressive results in a wide range of cancers. However, the response remains heterogeneous among patients. We used noninvasive immuno-positron emission tomography (PET), using 89Zr-labeled PEGylated single-domain antibody fragments (nanobodies or VHHs), to explore the dynamics and distribution of intratumoral CD8+ T cells and CD11b+ myeloid cells in response to anti-PD-1 treatment in the MC38 colorectal mouse adenocarcinoma model. Responding and nonresponding tumors showed consistent differences in the distribution of CD8+ and CD11b+ cells. Anti-PD-1 treatment mobilized CD8+ T cells from the tumor periphery to a more central location. Only those tumors fully infiltrated by CD8+ T cells went on to complete resolution. All tumors contained CD11b+ myeloid cells from the outset of treatment, with later recruitment of additional CD11b+ cells. As tumors grew, the distribution of intratumoral CD11b+ cells became more heterogeneous. Shrinkage of tumors in responders correlated with an increase in the CD11b+ population in the center of the tumors. The changes in distribution of CD8+ and CD11b+ cells, as assessed by PET, served as biomarkers to gauge the efficacy of anti-PD-1 treatment. Single-cell RNA sequencing of RNA from intratumoral CD45+ cells showed that CD11b+ cells in responders and nonresponders were markedly different. The responders exhibited a dominant population of macrophages with an M1-like signature, while the CD45+ population in the nonresponders displayed an M2-like transcriptional signature. Thus, by using immuno-PET and single-cell RNA sequencing, we show that anti-PD-1 treatment not only affects interactions of CD8+ T cells with the tumor but also impacts the intratumoral myeloid compartment.

Greater variability in lipid measurements associated with cardiovascular disease and mortality: A 10-year diabetes cohort study.

AIM: To examine the associations between variability in lipids and the risk of cardiovascular disease (CVD) and mortality in patients with type 2 diabetes based on low-density lipoprotein-cholesterol (LDL-C), the total cholesterol (TC) to high-density lipoprotein-cholesterol (HDL-C) ratio and triglycerides (TG). MATERIALS AND METHODS: A retrospective cohort study included 125 047 primary care patients with type 2 diabetes aged 45-84 years without CVD during 2008-2012. The variability of LDL-C, TC to HDL-C and TG was determined using the standard deviation of variables in a mixed effects model to minimize regression dilution bias. The associations between variability in lipids and CVD and mortality risk were assessed by Cox regression. Subgroup analyses based on patients' baseline characteristics were also conducted. RESULTS: A total of 19 913 CVD events and 15 329 mortalities were recorded after a median follow-up period of 77.5 months (0.8 million person-years), suggesting a positive linear relationship between variability in lipids and the risk of CVD and mortality. Each unit increase in the variability of LDL-C (mmol/L), the TC to HDL-C ratio and TG (mmol/L) was associated with a 27% (HR: 1.27 [95% CI: 1.20-1.34]), 31% (HR:1.31 [95% CI: 1.25-1.38]) and 9% (HR: 1.09 [95% CI: 1.04-1.15]) increase in the risk of composite endpoint of CVD and mortality, respectively. Age-specific effects were also found when comparing LDL-C variability, with patients aged 45-54 years (HR: 1.70 [95% CI: 1.42-2.02]) exhibiting a 53% increased risk for the composite endpoints than those aged 75-84 years (HR: 1.11 [95% CI: 1.01-1.23]). Similar age effects were observed for both the TC to HDL-C ratio and TG variability. Significant associations remained consistent among most of the subgroups. CONCLUSIONS: Variability in respective lipids are significant factors in predicting CVD and mortality in primary care patients with type 2 diabetes, with the strongest effects related to LDL-C and the TC to HDL-C ratio and most significant in the younger age group of patients aged 45-54 years. Further study is warranted to confirm these findings.

Combination of Type I and Type II MET Tyrosine Kinase Inhibitors as Therapeutic Approach to Prevent Resistance.

MET-targeted therapies are clinically effective in MET-amplified and MET exon 14 deletion mutant (METex14) non-small cell lung cancers (NSCLCs), but their efficacy is limited by the development of drug resistance. Structurally distinct MET tyrosine kinase inhibitors (TKIs) (type I/II) have been developed or are under clinical evaluation, which may overcome MET-mediated drug resistance mechanisms. In this study, we assess secondary MET mutations likely to emerge in response to treatment with single-agent or combinations of type I/type II MET TKIs using TPR-MET transformed Ba/F3 cell mutagenesis assays. We found that these inhibitors gave rise to distinct secondary MET mutant profiles. However, a combination of type I/II TKI inhibitors (capmatinib and merestinib) yielded no resistant clones in vitro The combination of capmatinib/merestinib was evaluated in vivo and led to a significant reduction in tumor outgrowth compared with either MET inhibitor alone. Our findings demonstrate in vitro and in vivo that a simultaneous treatment with a type I and type II MET TKI may be a clinically viable approach to delay and/or diminish the emergence of on target MET-mediated drug-resistance mutations.

Greater variability in lipid measurements associated with kidney diseases in patients with type 2 diabetes mellitus in a 10-year diabetes cohort study.

This study aimed to evaluate the associations between variability of lipid parameters and the risk of kidney disease in patients with type 2 diabetes mellitus. Low-density lipoprotein-cholesterol, total cholesterol to high-density lipoprotein-cholesterol ratio and triglyceride were specifically addressed in this study. This retrospective cohort study included 105,552 patients aged 45-84 with type 2 diabetes mellitus and normal kidney function who were managed under Hong Kong public primary care clinics during 2008-2012. Those with kidney disease (estimated glomerular filtration rate < 60 mL/min/1.73 m2 or urine albumin to creatinine ratio ≥ 3 mg/mmol) were excluded. Variabilities of low-density lipoprotein-cholesterol, total cholesterol to high-density lipoprotein-cholesterol ratio and triglyceride were determined using the standard deviation of the respective parameter obtained from a mixed effects model to minimize regression dilution bias. The associations between lipid variability and renal outcomes including incident kidney disease, renal function decline defined as ≥ 30% reduction in estimated glomerular filtration rate since baseline, and end-stage renal disease (estimated glomerular filtration rate < 15 mL/min/1.73 m2) were evaluated by multivariable Cox regression. After a median follow-up of 66.5 months (0.5 million person-years in total), 49,653 kidney disease, 29,358 renal function decline, and 1765 end-stage renal disease cases were recorded. Positive linear associations between low-density lipoprotein-cholesterol and total cholesterol to high-density lipoprotein-cholesterol ratio variabilities and the risk of all renal outcomes were demonstrated. However, no association between triglyceride variability and any outcome was found. Each mmol/L increase in low-density lipoprotein-cholesterol variability was associated with 20% (Hazard ratio 1.20 [95% CI 1.15-1.25]), 38% (Hazard ratio 1.37 [95% CI 1.30-1.45]), and 108% (Hazard ratio 2.08 [95% CI 1.74-2.50]) higher risk in incident kidney disease, renal function decline and end-stage renal disease respectively. Similarly, each unit increase in total cholesterol to high-density lipoprotein-cholesterol ratio variability was associated with 35% (Hazard ratio 1.15 [95% CI 1.10-1.20]), 33% (Hazard ratio 1.33 [95% CI 1.26-1.40]), and 75% (Hazard ratio 1.75 [95% CI 1.46-2.09]) heightened risk in incident kidney disease, renal function decline and end-stage renal disease respectively. Cholesterol variability may potentially be a useful predictor of kidney diseases in patients with type 2 diabetes mellitus. Attention should be drawn to cholesterol variability when managing diabetic patients and further research is warranted to investigate the modifiable risk factors for lipid variability.

Plasma ctDNA Response Is an Early Marker of Treatment Effect in Advanced NSCLC.

Plasma circulating tumor DNA (ctDNA) analysis is routine for genotyping of advanced non-small-cell lung cancer (NSCLC); however, early response assessment using plasma ctDNA has yet to be well characterized. MATERIALS AND METHODS: Patients with advanced EGFR-mutant NSCLC across three phase I NCI osimertinib combination trials were analyzed in this study, and an institutional cohort of patients with KRAS-, EGFR-, and BRAF-mutant advanced NSCLC receiving systemic treatment was used for validation. Plasma was collected before treatment initiation and serially before each cycle of therapy, and key driver mutations in ctDNA were characterized by droplet digital polymerase chain reaction. Timing of plasma versus imaging response was compared in a separate cohort of patients with EGFR-mutant NSCLC treated with osimertinib. Across cohorts, we also studied ctDNA variability before treatment start. RESULTS: In the NCI cohort, 14/16 (87.5%) patients exhibited ≥ 90% decrease in mutation abundance by the first on-treatment timepoint (20-28 days from treatment start) with minimal subsequent change. Similarly, 47/56 (83.9%) patients with any decrease in the institutional cohort demonstrated ≥ 90% decrease in mutation abundance by the first follow-up draw (7-30 days from treatment start). All 16 patients in the imaging cohort with radiographic partial response showed best plasma response within one cycle, preceding best radiographic response by a median of 24 weeks (range: 3-147 weeks). Variability in ctDNA levels before treatment start was observed. CONCLUSION: Plasma ctDNA response is an early phenomenon, with the majority of change detectable within the first cycle of therapy. These kinetics may offer an opportunity for early insight into treatment effect before standard imaging timepoints.

Validation of ctDNA Quality Control Materials Through a Precompetitive Collaboration of the Foundation for the National Institutes of Health.

We report the results from a Foundation for the National Institutes of Health Biomarkers Consortium project to address the absence of well-validated quality control materials (QCMs) for circulating tumor DNA (ctDNA) testing. This absence is considered a cause of variance and inconsistencies in translating ctDNA results into clinical actions. METHODS: In this phase I study, QCMs with 14 clinically relevant mutations representing single nucleotide variants, insertions or deletions (indels), translocations, and copy number variants were sourced from three commercial manufacturers with variant allele frequencies (VAFs) of 5%, 2.5%, 1%, 0.1%, and 0%. Four laboratories tested samples in quadruplicate using two allele-specific droplet digital polymerase chain reaction and three (amplicon and hybrid capture) next-generation sequencing (NGS) panels. RESULTS: The two droplet digital polymerase chain reaction assays reported VAF values very close to the manufacturers' claimed concentrations for all QCMs. NGS assays reported most single nucleotide variants and indels, but not translocations, close to the expected VAF values. Notably, two NGS assays reported lower VAF than expected for all translocations in all QCM mixtures, possibly related to technical challenges detecting these variants. The ability to call ERBB2 copy number amplifications varied across assays. All three QCMs provided valuable insight into assay precision. Each assay across all variant types demonstrated dropouts at 0.1%, suggesting that the QCM can serve for testing of an assay's limit of detection with confidence claims for specific variants. CONCLUSION: These results support the utility of the QCM in testing ctDNA assay analytical performance. However, unique designs and manufacturing methods for the QCM, and variations in a laboratory's testing configuration, may require testing of multiple QCMs to find the best reagents for accurate result interpretation.

Phase IB Study of Osimertinib in Combination with Navitoclax in EGFR-mutant NSCLC Following Resistance to Initial EGFR Therapy (ETCTN 9903).

PURPOSE: Osimertinib is an effective therapy in EGFR-mutant non-small cell lung cancer (NSCLC), but resistance invariably develops. Navitoclax is an oral inhibitor of BCL-2/BCL-xL that has exhibited synergy with osimertinib in preclinical models of EGFR-mutant NSCLC. In hematologic malignancies, BCL-2 family inhibitors in combination therapy effectively increase cellular apoptosis and decrease drug resistance. PATIENTS AND METHODS: This single-arm phase Ib study evaluated safety, tolerability, and feasibility of osimertinib and navitoclax, including dose expansion in T790M-positive patients at the recommended phase II dose (RP2D). Eligible patients had advanced EGFR-mutant NSCLC with prior tyrosine kinase inhibitor exposure. Five dose levels were planned with osimertinib from 40 to 80 mg orally daily and navitoclax from 150 to 325 mg orally daily. RESULTS: A total of 27 patients were enrolled (18 in the dose-escalation cohort and nine in the dose-expansion cohort): median age 65, 67% female, 48% exon 19 del, and 37% L858R, median one prior line of therapy. The most common adverse events were lymphopenia (37%), fatigue (22%), nausea (22%), and thrombocytopenia (37%). No dose-limiting toxicities were seen in dose-escalation cohort; osimertinib 80 mg, navitoclax 150 mg was chosen as the RP2D. Most patients (78%) received >95% of planned doses through three cycles. In expansion cohort, objective response rate was 100% and median progression-free survival was 16.8 months. A proapoptotic effect from navitoclax was demonstrated by early-onset thrombocytopenia. CONCLUSIONS: Oral combination therapy with navitoclax and osimertinib was safe and feasible at RP2D with clinical efficacy. Early thrombocytopenia was common, supporting an target engagement by navitoclax. Further study of BCL-2/BCL-xL inhibition to enhance osimertinib activity is warranted.

Dynamic single-cell RNA sequencing identifies immunotherapy persister cells following PD-1 blockade.

Resistance to oncogene-targeted therapies involves discrete drug-tolerant persister cells, originally discovered through in vitro assays. Whether a similar phenomenon limits efficacy of programmed cell death 1 (PD-1) blockade is poorly understood. Here, we performed dynamic single-cell RNA-Seq of murine organotypic tumor spheroids undergoing PD-1 blockade, identifying a discrete subpopulation of immunotherapy persister cells (IPCs) that resisted CD8+ T cell-mediated killing. These cells expressed Snai1 and stem cell antigen 1 (Sca-1) and exhibited hybrid epithelial-mesenchymal features characteristic of a stem cell-like state. IPCs were expanded by IL-6 but were vulnerable to TNF-α-induced cytotoxicity, relying on baculoviral IAP repeat-containing protein 2 (Birc2) and Birc3 as survival factors. Combining PD-1 blockade with Birc2/3 antagonism in mice reduced IPCs and enhanced tumor cell killing in vivo, resulting in durable responsiveness that matched TNF cytotoxicity thresholds in vitro. Together, these data demonstrate the power of high-resolution functional ex vivo profiling to uncover fundamental mechanisms of immune escape from durable anti-PD-1 responses, while identifying IPCs as a cancer cell subpopulation targetable by specific therapeutic combinations.

EGFR-Mutated Lung Cancers Resistant to Osimertinib through EGFR C797S Respond to First-Generation Reversible EGFR Inhibitors but Eventually Acquire EGFR T790M/C797S in Preclinical Models and Clinical Samples.

INTRODUCTION: Osimertinib is approved for advanced EGFR-mutated NSCLC, and identification of on-target mechanisms of resistance (i.e., EGFR C797S) to this third-generation EGFR inhibitor are evolving. Whether durable control of subsequently osimertinib-resistant NSCLC with the EGFR-sensitizing mutation (SM)/C797S is possible with first-generation EGFR inhibitors (such as gefitinib or erlotinib) remains underreported, as does the resultant acquired resistance profile. METHODS: We used N-ethyl-N-nitrosourea mutagenesis to determine the profile of EGFR SM/C797S preclinical models exposed to reversible EGFR inhibitors. In addition, we retrospectively probed a case of EGFR SM lung adenocarcinoma treated with first-line osimertinib, followed by second-line erlotinib in the setting of EGFR SM/C797S. RESULTS: Use of N-ethyl-N-nitrosourea mutagenesis against the background of EGFR L858R/C797S in conjunction with administration of gefitinib revealed preferential outgrowth of cells with EGFR L858R/T790M/C797S. A patient with EGFR delE746_T751insV NSCLC was treated with osimertinib with sustained response for 10 months before acquiring EGFR C797S. The patient was subsequently treated with erlotinib, with response for a period of 4 months, but disease progression ensued. Liquid biopsy disclosed EGFR delE746_T751insV with T790M and C797S present in cis. CONCLUSION: EGFR SM NSCLC can acquire resistance to osimertinib through development of the EGFR C797S mutation. In this clinical scenario, the tumor may respond transiently to reversible first-generation EGFR inhibitors (gefitinib or erlotinib), but evolving mechanisms of on-target resistance-in clinical specimens and preclinical systems-indicate that EGFR C797S along with EGFR T790M can evolve. This report adds to the growing understanding of tumor evolution or adaptability to sequential EGFR inhibition and augments support for exploring combination therapies to delay or prevent on-target resistance.

Salivary HPV DNA informs locoregional disease status in advanced HPV-associated oropharyngeal cancer.

OBJECTIVES: Quantifying tumor DNA in tissue and circulating in blood permits high-quality molecular monitoring to detect and track cancer progression. Evaluating tumor DNA in both blood and saliva in human papillomavirus (HPV)-associated oropharyngeal cancer (OPC) could provide a non-invasive and clinically actionable method for real-time disease detection. METHODS: We previously validated an ultrasensitive droplet-digital (dd)PCR assay targeting the dominant high-risk HPV subtypes causally linked to OPC. Here we enrolled an observational cohort to evaluate the predictive and prognostic potential of paired plasma-salivary tumor DNA among 21 patients with advanced HPV+OPC. RESULTS: In patients with recurrent, persistent locoregional (LR) disease, median baseline normalized salivary HPV DNA was 10.9 copies/ng total DNA, nearly 20x higher compared with those with distant disease only (p = 0.01). A cutoff of 5 copies/ng yielded 87% sensitivity and 67% specificity for accurately predicting LR disease. Total tumor burden among those with LR disease strongly correlated with salivary HPV DNA levels (R = 0.83, p = 0.02). The rise and fall of salivary HPV DNA predicted treatment failure and response, respectively, in all patients with LR disease, and predated imaging findings. Among paired salivary-plasma (cell-free) cfDNA samples, only higher plasma HPV cfDNA levels were associated with poor outcomes (p < 0.01), suggesting that each bodily fluid provides unique information about HPV disease status. CONCLUSIONS: Salivary HPV DNA provides valuable information about tumor burden and predicts treatment response in advanced HPV+OPC. Paired blood-saliva samples could be used to monitor HPV DNA with broad applications to inform diagnosis, prognosis, and surveillance in HPV-associated diseases.

Effect of Erlotinib Plus Bevacizumab vs Erlotinib Alone on Progression-Free Survival in Patients With Advanced EGFR-Mutant Non-Small Cell Lung Cancer: A Phase 2 Randomized Clinical Trial.

IMPORTANCE: Erlotinib is a standard first-line therapy for patients with epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC). Median progression-free survival (PFS) with erlotinib is approximately 10 months. OBJECTIVE: To determine whether adding bevacizumab to erlotinib treatment results in superior progression-free survival compared with erlotinib alone. DESIGN, SETTING, AND PARTICIPANTS: This phase 2 randomized clinical trial compared erlotinib plus bevacizumab with erlotinib alone in EGFR-mutant NSCLC. The trial was conducted in 17 US academic and community medical centers among 88 patients with EGFR exon 19 deletion or exon 21 L858R mutation based on local testing and stage 4 NSCLC who were eligible for bevacizumab. Patients were enrolled between November 2, 2012, and August 22, 2016, and followed up for a median (range) of 33 (0.7-62.5) months. Data were analyzed on August 28, 2018, and included data from November 2, 2012, to August 20, 2018. INTERVENTIONS: Patients were randomized with equal allocation to 150 mg of oral erlotinib daily alone or with 15 mg/kg of intravenous bevacizumab every 3 weeks. Study therapy continued until disease progression, unacceptable adverse event, or withdrawal of consent. MAIN OUTCOMES AND MEASURES: The primary outcome was PFS as assessed by the investigator; secondary outcomes were objective response rate (ORR), adverse events, and overall survival (OS). Analysis was designed to detect a hazard ratio (HR) of 0.667 for PFS (an improvement from a median PFS of 10 to 15 months). RESULTS: Among 88 patients enrolled, the median (range) age was 63 (31-84) years; 62 patients (70%) were female; 75 (85%) were white, 8 (9%) were African American, 3 (3%) were Asian, and for 2 (2%), data on race were not available. Forty-eight patients (55%) were never smokers, 45 patients (51%) were of Eastern Cooperative Oncology Group performance status 1, and 59 patients (67%) had EGFR exon 19 deletion. Compared with erlotinib, the combination did not result in a significant difference in PFS (HR, 0.81; 95% CI, 0.50-1.31; P = .39; median PFS 17.9 [combination] and 13.5 months [erlotinib]), ORR (81% vs 83%; P = .81), and OS (HR, 1.41; 95% CI, 0.71-2.81; P = .33; median OS, 32.4 months [combination] and 50.6 months [erlotinib]). Adverse events of grade 3 or higher observed in 5 or more patients in the combination and erlotinib arms were skin eruption in 11 (26%) vs 7 (16%) patients, diarrhea in 4 (9%) vs 6 (13%) patients, hypertension in 17 (40%) vs 9 (20%) patients, and proteinuria in 5 (12%) vs 0 (0%) patients. CONCLUSIONS AND RELEVANCE: Erlotinib plus bevacizumab compared with erlotinib did not result in a significant improvement in PFS in EGFR-mutant NSCLC. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01532089.