Molecular characterization of acquired resistance to KRAS G12C inhibition in gastrointestinal cancers

KRAS G12C inhibitors, such as sotorasib, have rapidly moved through clinical development and are poised to transform care of patients with KRAS G12C mutant cancers, in particular non-small cell lung cancer (NSCLC) and colorectal cancer (CRC). Clinical efficacy is achieved in NSCLC as a single agent and in CRC in combination with anti-EGFR monoclonal antibodies, however, secondary resistance impairs the effects of KRAS G12C blockade. In this work, we sought to determine the mechanisms of acquired resistance to concomitant KRAS-EGFR inhibition. In cell lines, patient-derived xenograft, and patient samples, a heterogeneous pattern of putative resistance alterations expected primarily to prevent inhibition of ERK signalling by drug can be detected at progression. Serial analysis of patient blood samples on treatment demonstrates that most of these alterations are detected at a low frequency that does not increase substantially and sometimes disappears over time, with the exception of KRAS G12C amplification which rises in step with tumour marker levels and clinical progression. Here we show that a CRC cell line that acquired resistance to sotorasib-cetuximab combination through KRAS G12C amplification became addicted to these agents and undergoes oncogene-induced senescence upon drug withdrawal. Accordingly, the KRAS G12C signal in circulating DNA from relapsed patients harbouring G12C amplification rapidly recedes upon treatment holiday. These data indicate that KRAS G12C amplification is a recurrent resistance mechanism to KRAS-EGFR co-inhibition and suggest a potential therapeutic vulnerability, whereby therapies that target this senescence response at drug withdrawal may overcome resistance to KRAS G12C-EGFR inhibition.

Transient Exposure of Endothelial Cells to Doxorubicin Leads to Long-Lasting Vascular Endothelial Growth Factor Receptor 2 Downregulation

Doxorubicin (Dox) is an effective antineoplastic drug with serious cardiotoxic side effects that persist after drug withdrawal and can lead to heart failure. Dysregulation of vascular endothelium has been linked to the development of Dox-induced cardiotoxicity, but it is unclear whether and how transient exposure to Dox leads to long-term downregulation of Endothelial Vascular Endothelial Growth Factor Receptor type2 (VEGFR2), essential for endothelial cells function. Using an in vitro model devised to study the long-lasting effects of brief endothelial cells exposure to Dox, we show that Dox leads to sustained protein synthesis inhibition and VEGFR2 downregulation. Transient Dox treatment led to the development of long-term senescence associated with a reduction in VEGFR2 levels that persisted days after drug withdrawal. By analyzing VEGFR2 turnover, we ruled out that its downregulation was depended on Dox-induced autophagy. Conversely, Dox induced p53 expression, reduced mTOR-dependent translation, and inhibited global protein synthesis. Our data contribute to a mechanistic basis to the permanent damage caused to endothelial cells by short-term Dox treatment.

DILI-Stk: An ensemble model for the prediction of drug-induced liver injury of drug candidates

Background: Drug-induced liver injury (DILI) is a leading cause of drug failure, accounting for nearly 20% of drug withdrawal. Thus, there has been a great demand for in silico DILI prediction models for successful drug discovery. To date, various models have been developed for DILI prediction; however, building an accurate model for practical use in drug discovery remains challenging. Methods: We constructed an ensemble model composed of three high-performance DILI prediction models to utilize the unique advantage of each machine learning algorithm. Results: The ensemble model exhibited high predictive performance, with an area under the curve of 0.88, sensitivity of 0.83, specificity of 0.77, F1-score of 0.82, and accuracy of 0.80. When a test dataset collected from the literature was used to compare the performance of our model with publicly available DILI prediction models, our model achieved an accuracy of 0.77, sensitivity of 0.82, specificity of 0.72, and F1-score of 0.79, which were higher than those of the other DILI prediction models. As many published DILI prediction models are not available for public access, which hinders in silico drug discovery, we made our DILI prediction model publicly accessible (http://ssbio.cau.ac.kr/software/dili/). Conclusion: We expect that our ensemble model may facilitate advancements in drug discovery by providing a highly predictive model and reducing the drug withdrawal rate.

Neuroendocrinology of Stress and Addiction

The stress response evolved as a series of neural and endocrine mechanisms that protect the host organism from threats to homeostasis. Repeated use of psychotropic drugs can lead to the development of tolerance (i.e., decreased drug activity at a given dose) and drug dependence, as indicated by withdrawal syndromes following drug abstinence. Drug withdrawal is often overtly stressful, although acute drug exposure may also represent a threat to homeostasis. This article explores the neuroendocrine effects of drugs of abuse and some of the ways in which stress and appetitive mechanisms interact.

Topical Cyclosporine in Oral Lichen Planus—A Series of 21 Open-Label, Biphasic, Single-Patient Observations

Topical cyclosporine (CSA) has been reported as an alternative treatment in steroid-refractory oral lichen planus (OLP), but evidence is limited and conflicting. An N-of-1 trial setting could be appropriate to evaluate interindividual differences in treatment response. We studied a series of 21 open-label, biphasic single-patient observations. Patients (15 women, 6 men) with OLP recalcitrant to topical steroids received four weeks of CSA mouth rinse (200 mg/twice daily) followed by four weeks of drug withdrawal. Pain (visual analogue scale (VAS) score), disease extent (physicians’ global assessment (PGA) score) and quality of life (Dermatology Life Quality Index (DLQI) score,) were assessed at baseline (T0), after four weeks of treatment (T1) and after another four weeks without treatment (T2). Median age was 58 years (interquartile range/IQR = 52–67) and median disease duration was 18 months (IQR = 12–44). Median baseline VAS score decreased significantly at T1 (p = 0.0003) and increased at T2 (p = 0.032) (T0 = 5 (IQR = 3–6.5); T1 = 2 (IQR = 0.5–3.4); T2 = 3 (IQR = 2–4.8)). Similarly, median baseline PGA score decreased significantly at T1 (p = 0.001) and increased at T2 (p = 0.007) (T0 = 2 (IQR = 1.3–2.5); T1 = 1 (IQR = 1–2); T2 = 2 (IQR = 1–2)). Median baseline DLQI score also decreased significantly at T1 (p =.027) but did not change at T2 (p = 0.5) (T0 = 2.5 (IQR = 1–5.8); T1 = 1 (IQR = 0–3); T2 = 1 (IQR = 1–4)). CSA responders (n = 16) had significantly higher median baseline VAS scores (5.2 (IQR = 5–6.5)) than nonresponders (n =5) (2 (IQR = 2–3.5) (p = 0.02). In our study, pain, disease extent and quality of life of patients with OLP improved significantly during therapy with low-dose CSA mouth rinse and exacerbated after drug withdrawal. Remarkably, patients with high initial VAS scores seemed to profit most.

Experience of long-term use of denosumab in women with osteoporosis and various concomitant diseases

Background: Possible differences in the results of planned RCTs and real clinical practice were the reason for the analysis of long-term therapy with denosumab in patients with osteoporosis (OP) of various origins on an outpatient basis.Aim: To assess the effectiveness of long-term administration of denosumab in terms of the effect on BMD and markers of bone metabolism, tolerance and consequences of drug withdrawal in patients with OP of various etiologies.Materials And Methods: A retrospective analysis of the outpatient records of women with OP of various etiology, who were observed at the FSBI «NMRC TPM» from 1 to 10 years and regularly received denosumab 60 mg once every 6 months subcutaneously (at least 2 injections), was carried out. All completed examination and anthropometric research; DXA of the lumbar spine and proximal femur (PF); laboratory tests: marker of bone resorption CTx (β-crosslaps) in blood serum; survey on the presence of adverse events.Results: The study included 148 patients who were divided into 2 groups: 1 (N=98) - did not take anti-osteoporotic therapy (AT), 2 (N=50) - who took AT before the appointment of denosumab. Long-term therapy with denosumab was associated with a steady and reliable increase in BMD in the spine and PF, as well as a decrease in the concentration of CTx of both those who didn’t take and who previously took AT. In 54% of patients BMD in the spine reached values of osteopenia, in 43.4% of women target BMD values in the femoral neck were determined. During the first year of therapy, there was a decrease in the concentration of CTx by 67% in those who didn’t take AT and by 58% in those who had previously taken AT. Discontinuation of denosumab therapy without subsequent administration of AT was associated with a significant decrease in BMD in the spine (by 4.4-8.2%) during the first year after discontinuation of the drug.Conclusion: Denosumab therapy effectively increases BMD in the spine and PF and decreases CTx levels both in untreated patients and in those who previously received AT. It is necessary to discontinue therapy, further management of the patient should be discussed to prevent «withdrawal syndrome».

Time to abandon ampicillin plus gentamicin in favour of ampicillin plus ceftriaxone in Enterococcus faecalis infective endocarditis? A meta-analysis of comparative trials

Background Current guidelines recommend either ampicillin plus ceftriaxone (AC) or amoxicillin/ampicillin plus gentamicin (AG) with an equivalent class IB recommendation in Enterococcus faecalis endocarditis. However, previous observational studies suggest that AC might be favourable in terms of adverse events. Objectives To investigate whether AC is non-inferior to AG, and if it is associated with less adverse events. Methods In June 2021, a systematic literature search using the databases PubMed/MEDLINE, CDSR, CENTRAL, CCAs, EBM Reviews, Web of Science and LILACS was conducted by two independent reviewers. Studies were considered eligible if (P) patients included were ≥ 18 years of age and had IE with E. faecalis, (I) treatment with AC was compared to (C) treatment with AG and (O) outcomes on in-hospital mortality, nephrotoxicity and adverse events requiring drug withdrawal were reported. Odds ratios and 95% confidence intervals were calculated using random-effects models with the Mantel–Haenszel method, the Sidik–Jonkman estimator for τ2 and the Hartung–Knapp adjustment. Results Treatment with AC was non-inferior to AG, as depicted by no significant differences in-hospital mortality, 3-month mortality, relapses or treatment failure. Furthermore, AC was associated with a lower prevalence of nephrotoxicity (OR 0.45 [0.26–0.77], p = 0.0182) and drug withdrawal due to adverse events (OR 0.11 [0.03–0.46], p = 0.0160) than AG. Conclusions Treatment with AC was non-inferior to treatment with AG, and it was associated with a reduced prevalence of nephrotoxicity and drug withdrawal due to adverse events. Thus, combination therapy with AC appears favourable over AG in patients with E. faecalis IE. Graphical abstract

Assessment of Calcium and Vitamin D Medications Adherence in Patients with Hypoparathyroidism After Thyroidectomy

Summary: In this study, we found that patients with hypoparathyroidism had a problem with calcium medication compliance, and this problem increased with the duration of the disease. We also showed that patients are concerned about the possible side effects of drugs.Introduction: In this study, we aimed to evaluate adherence to avtive vitamin D and calcium replacement in patients with post surgical hypoparathyroidism.Methods: To elucidate the medication adherence, we performed a questionnaire survey using the six item “Medication adherence questionnaire’’(MAQ). The first, second and sixth questions reflect the motivation status of the patients whereas the third, forth and sixth questions reflect the knowledge about the medication that is received. The responses are scored and patients are classified regarding their motivation to and knowledge about the particular drug.Results: Totally 64 patients (Male:12/Female:52; mean age 48.6±11.6 years) who had postoperative hypoparathyroidism were included in our study. Median disease durance was 60 months (min-max; 12-295 months). We found that motivation score of calcium usage was significantly lower compared to vitamin D usage (p<0.001). The calcium motivation score was reversely correlated with disease duration (r= -0.256 and p=0.046). The most common worry about calcium usage was nephrotoxicity, and the most common worries about calcitriol treatment were kidney damage and polyuria. One third of the patients were taking oral calcium and calcitriol less than the recommended dose.Conclusion: One third of patients lack motivation to use calcium whereas half of the patients’ experiences anxiety about drug related side effects. This is a preliminary study showing that vital calcium and active vitamin D intake may be interrupted due to side effect anxiety and motivation can be increased by frequent visits and acknowledging the patient about the deleterious effects of drug withdrawal.

Clinically relevant doses of methylphenidate elicit behavioral sensitization and impair cognition on drug withdrawal in normal adult rats

Methylphenidate (MPD), a psychostimulant, is the first line drug for improving cognitive performance in attention deficit hyperactivity disorder (ADHD). A non-prescription use of this drug for improving performance is also becoming increasingly known. A growing rise in its medical and nonmedical use suggests that the drug is addictive.The present study was designed to ascertain the reinforcing and withdrawal effects of clinically relevant doses of methylphenidate on cognitive behavior of normal adult rats. Potential addictive effects and withdrawal effects on cognition were also determined.Effects of MPD in improving cognition were monitored after drug administration as well as withdrawal using Morris Water Maze test. Taking behavioral sensitization as an important contributing factor of drug addiction; addictive effects of MPD were also determined. Data analysis was done on SPSS version 13 by one-way and two-way ANOVA (repeated measure design) where applicable; post hoc comparisons were done by Tukey’s test. Repeated oral administration of MPD (0.5 and 1mg/kg) for six days produced behavioral sensitization and reduced daily food intake. After six days of treatment rats were repeatedly administered/withdrawal from repeated administration of MPD to investigate effects of MPD on cognitive behaviors. Results showed an improvement in cognition in rats repeatedly administered with MPD (0.5 and 1 mg/kg). Whereas, withdrawal from repeated administration of MPD impaired short term memory, long term memory and memory retention. Doses of MPD which improve learning and memory are potentially addictive and elicit behavioral sensitization. Use of drug in healthy subjects can impair performance below basal levels particularly in drug withdrawal conditions.