Selective Noradrenaline Depletion in the Neocortex and Hippocampus Induces Working Memory Deficits and Regional Occurrence of Pathological Proteins

Noradrenaline (NA) depletion occurs in Alzheimer's disease (AD); however, its relationship with the pathological expression of Tau and transactive response DNA-binding protein 43 (TDP-43), two major hallmarks of AD, remains elusive. Here, increasing doses of a selective noradrenergic immunotoxin were injected into developing rats to generate a model of mild or severe NA loss. At about 12 weeks post-lesion, dose-dependent working memory deficits were detected in these animals, associated with a marked increase in cortical and hippocampal levels of TDP-43 phosphorylated at Ser 409/410 and Tau phosphorylated at Thr 217. Notably, the total levels of both proteins were largely unaffected, suggesting a direct relationship between neocortical/hippocampal NA depletion and the phosphorylation of pathological Tau and TDP-43 proteins. As pTD43 is present in 23% of AD cases and pTau Thr217 has been detected in patients with mild cognitive impairment that eventually would develop into AD, improvement of noradrenergic function in AD might represent a viable therapeutic approach with disease-modifying potential.

IMI2-PainCare-BioPain-RCT3: a randomized, double-blind, placebo-controlled, crossover, multi-center trial in healthy subjects to investigate the effects of lacosamide, pregabalin, and tapentadol on biomarkers of pain processing observed by electroencephalography (EEG)

Background

IMI2-PainCare-BioPain-RCT3 is one of four similarly designed clinical studies aiming at profiling a set of functional biomarkers of drug effects on the nociceptive system that could serve to accelerate the future development of analgesics, by providing a quantitative understanding between drug exposure and effects of the drug on nociceptive signal processing in human volunteers. IMI2-PainCare-BioPain-RCT3 will focus on biomarkers derived from non-invasive electroencephalographic (EEG) measures of brain activity.

Methods

This is a multisite single-dose, double-blind, randomized, placebo-controlled, 4-period, 4-way crossover, pharmacodynamic (PD) and pharmacokinetic (PK) study in healthy subjects. Biomarkers derived from scalp EEG measurements (laser-evoked brain potentials [LEPs], pinprick-evoked brain potentials [PEPs], resting EEG) will be obtained before and three times after administration of three medications known to act on the nociceptive system (lacosamide, pregabalin, tapentadol) and placebo, given as a single oral dose in separate study periods. Medication effects will be assessed concurrently in a non-sensitized normal condition and a clinically relevant hyperalgesic condition (high-frequency electrical stimulation of the skin). Patient-reported outcomes will also be collected. A sequentially rejective multiple testing approach will be used with overall alpha error of the primary analysis split between LEP and PEP under tapentadol. Remaining treatment arm effects on LEP or PEP or effects on EEG are key secondary confirmatory analyses. Complex statistical analyses and PK-PD modeling are exploratory.

Discussion

LEPs and PEPs are brain responses related to the selective activation of thermonociceptors and mechanonociceptors. Their amplitudes are dependent on the responsiveness of these nociceptors and the state of the pathways relaying nociceptive input at the level of the spinal cord and brain. The magnitude of resting EEG oscillations is sensitive to changes in brain network function, and some modulations of oscillation magnitude can relate to perceived pain intensity, variations in vigilance, and attentional states. These oscillations can also be affected by analgesic drugs acting on the central nervous system. For these reasons, IMI2-PainCare-BioPain-RCT3 hypothesizes that EEG-derived measures can serve as biomarkers of target engagement of analgesic drugs for future Phase 1 clinical trials. Phase 2 and 3 clinical trials could also benefit from these tools for patient stratification.

Trial registration

This trial was registered 25/06/2019 in EudraCT (2019%2D%2D001204-37).

Human surrogate models of central sensitization: A critical review and practical guide

Background

As in other fields of medicine, development of new medications for management of neuropathic pain has been difficult since preclinical rodent models do not necessarily translate to the clinics. Aside from ongoing pain with burning or shock‐like qualities, neuropathic pain is often characterized by pain hypersensitivity (hyperalgesia and allodynia), most often towards mechanical stimuli, reflecting sensitization of neural transmission.

Data treatment

We therefore performed a systematic literature review (PubMed‐Medline, Cochrane, WoS, ClinicalTrials) and semi‐quantitative meta‐analysis of human pain models that aim to induce central sensitization, and generate hyperalgesia surrounding a real or simulated injury.

Results

From an initial set of 1569 reports, we identified and analysed 269 studies using more than a dozen human models of sensitization. Five of these models (intradermal or topical capsaicin, low‐ or high‐frequency electrical stimulation, thermode‐induced heat‐injury) were found to reliably induce secondary hyperalgesia to pinprick and have been implemented in multiple laboratories. The ability of these models to induce dynamic mechanical allodynia was however substantially lower. The proportion of subjects who developed hypersensitivity was rarely provided, giving rise to significant reporting bias. In four of these models pharmacological profiles allowed to verify similarity to some clinical conditions, and therefore may inform basic research for new drug development.

Conclusions

While there is no single “optimal” model of central sensitization, the range of validated and easy‐to‐use procedures in humans should be able to inform preclinical researchers on helpful potential biomarkers, thereby narrowing the translation gap between basic and clinical data.

Significance

Being able to mimic aspects of pathological pain directly in humans has a huge potential to understand pathophysiology and provide animal research with translatable biomarkers for drug development. One group of human surrogate models has proven to have excellent predictive validity: they respond to clinically active medications and do not respond to clinically inactive medications, including some that worked in animals but failed in the clinics. They should therefore inform basic research for new drug development.

Genomic Profiling Identifies Outcome-Relevant Mechanisms of Innate and Acquired Resistance to Third-Generation Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor Therapy in Lung Cancer

PURPOSE

Third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) are effective in acquired resistance (AR) to early-generation EGFR TKIs in EGFR-mutant lung cancer. However, efficacy is marked by interindividual heterogeneity. We present the molecular profiles of pretreatment and post-treatment samples from patients treated with third-generation EGFR TKIs and their impact on treatment outcomes.

METHODS

Using the databases of two lung cancer networks and two lung cancer centers, we molecularly characterized 124 patients with EGFR p.T790M-positive AR to early-generation EGFR TKIs. In 56 patients, correlative analyses of third-generation EGFR TKI treatment outcomes and molecular characteristics were feasible. In addition, matched post-treatment biopsy samples were collected for 29 patients with progression to third-generation EGFR TKIs.

RESULTS

Co-occurring genetic aberrations were found in 74.4% of EGFR p.T790-positive samples (n = 124). Mutations in TP53 were the most frequent aberrations detected (44.5%; n = 53) and had no significant impact on third-generation EGFR TKI treatment. Mesenchymal-epithelial transition factor (MET) amplifications were found in 5% of samples (n = 6) and reduced efficacy of third-generation EGFR TKIs significantly (eg, median progression-free survival, 1.0 months; 95% CI, 0.37 to 1.72 v 8.2 months; 95% CI, 1.69 to 14.77 months; P ≤ .001). Genetic changes in the 29 samples with AR to third-generation EGFR TKIs were found in EGFR (eg, p.T790M loss, acquisition of p.C797S or p.G724S) or in other genes (eg, MET amplification, KRAS mutations).

CONCLUSION

Additional genetic aberrations are frequent in EGFR-mutant lung cancer and may mediate innate and AR to third-generation EGFR TKIs. MET amplification was strongly associated with primary treatment failure and was a common mechanism of AR to third-generation EGFR TKIs. Thus, combining EGFR inhibitors with TKIs targeting common mechanisms of resistance may delay AR.

Molecular panel sequencing of pre-treatment samples to reveal mechanisms of innate resistance to 3rd generation EGFR TKI treatment in T790M-positive NSCLC patients

9041

Background: Resistance to early generation epidermal growth factor receptor ( EGFR) tyrosine kinase inhibitors (TKI) inevitably develops in EGFR-mutant lung cancer. The secondary EGFR p.T790M mutation is the driving factor in 60% of cases and 3rd generation EGFR TKIs have been developed to overcome T790M-mediated resistance. However, besides T790M other genetic aberrations such as amplifications of MET may contribute to resistance to EGFR inhibition in the same patient. We here report on the systematic analysis of co-occurring genetic aberrations that may influence response to 3rd generation EGFR TKIs. Methods: Thirty-six patients were treated with 3rd generation EGFR TKIs in the setting of acquired resistance to EGFR inhibition in cancer centers in Germany and Switzerland. Pre-treatment samples were analyzed for co-occurring genetic aberrations in a subset of resistance-related genes including MET, HER2, RAS-gene family, PIK3CA, CTNNB1 and PTEN using next-generation sequencing and fluorescence in-situ hybridization assays. We investigated the association between clinical, epidemiological and molecular data and response to treatment (RECIST 1.1). Results: Co-occurring genetic aberrations were found in 68% of the pre-treatment samples where both, analyses by sequencing and FISH were feasible (N = 25). Efficacy of 3rd generation EGFR TKIs significantly dropped in the presence of high-level MET amplification as compared to wild-type MET (ORR, 0.0%; 95% CI, 0.0-60.4 vs. 70.0%; 95% CI, 45.7-87.2; p = 0.02; median PFS, 1.0 month; 95% CI, 0.37-1.72 months vs. 8.2 months; 95% CI, 1.69-14.77 months; p ≤ 0.001). No statistically significant association was found between treatment efficacy and the molecular status of the genes analyzed or the number of prior EGFR TKIs. Conclusions: Prevalence of additional genetic aberrations is frequent in the setting of acquired resistance to early generation EGFR TKIs and may not necessarily mediate resistance to 3rd generation EGFR TKIs. However, in our analysis high-level amplification of MET was associated with primary treatment failure and might be the main factor underlying resistance in this setting.

Expanded molecular routine testing for targetable mutations in non-small cell lung cancer to reveal frequent co-occuring mutations

e20596

Background: Using next-gen sequencing of predefined gene panels in routine clinical diagnostics of lung cancer allows, in contrast to single-gene assays, assessment of co-occuring mutations, which might underly heterogeneity of response to targeted drugs and survival. The Network Genomic Medicine (NGM) performs high sensitive next generation sequencing (NGS) based routine molecular diagnostics on a central platform for about 5000 inoperable lung cancer patients (pts) annually in Germany. Methods: NGS panel used in NGM consists of 17 genes to cover potentially targetable aberrations. Mutation analyses were run on an Illumina (MySeq) platform, while FISH analyses were performed separately. In 2016, we have started the evaluation of all NGM pts with available clinical data who had received NGS-based molecular diagnostics. In particular, we have focused on non-squamous (non-sq) and squamous (sq) NSCLC pts with co-occurring mutations: their frequency, significance and impact on overall survival. Results: From 2014 molecular genotyping was performed for 7,893 NGM pts (n = 7,246 NSCLC (5,667 non-sq and 1,487 sq pts) and n = 489 SCLC) with eligible clinical data. Genetic alterations in transformation-associated pathways were found in 79 % of all NSCLC pts. Furthermore, co-occurring mutations were detected in 39 % of these pts: 40 % in non-sq and 37 % in sq NSCLC. 11 % of pts had more than 2 co-occurring mutations. 1 % of all pts had 5 co-occurring mutations. The most frequent paired mutations were KRAS, EGFR and MET each with TP53 in non-sq and FRGF1 and TP53 in sq NSCLC. The incidences and significance of 3, 4 and 5 co-mutations as well as the impact of these co-occurring mutations on overall survival will be presented. Conclusions: Frequent occurrence of co-occuring mutations in transformation – associated pathways underlines the genetic heterogeneity also of lung cancer with classical driver mutation and the impact of co-occurring mutations on survival. This work confirms the use of molecular multiplex testing in routine molecular diagnostics of NSCLC. Assessment of co-occuring mutations will help to further specify genetically defined subgroups of lung cancer with therapeutic relevance.

Economic evaluation of chronic lymphocytic leukemia from a hospital management perspective

OBJECTIVES

Treatment of chronic lymphocytic leukemia (CLL) is currently undergoing dramatic changes. We analyzed economic risks in hospitalized patients with CLL from a management perspective.

METHODS

One hundred and twelve patients with CLL hospitalized in 2013 and 2014 at the University Hospital of Cologne were analyzed. To assess profit margins (PMs) per case, diagnosis-related group (DRG) reimbursement data were merged with an internal cost accounting scheme depending on age, prognostic factors, and DRG key performance indicators.

RESULTS

In 112 patients, 284 cases coded by 19 different DRG with strongly fluctuating cost revenue ratios were found with an overall negative PM of €137 147. The DRG R61H was identified as the one most commonly coded (174 cases, 61.3%) with a deficit per case of €814. Subanalysis demonstrated that the payments were not cost covering due to excessive length of stay and staff costs. Significant differences in PM per case concerning age, length of stay and number of operation and procedure key (OPS) codes (P < 0.05) were found.

CONCLUSION

In our research-driven tertiary care hospital, inpatient treatment of patients with CLL is not cost covering. This analysis demonstrates the need for novel care/reimbursement structures in CLL. From a hospital management perspective, cost revenue controlling is crucial to avoid major economic risks.