Safety profile of chloroquine and hydroxychloroquine: a disproportionality analysis of the FDA Adverse Event Reporting System database

OBJECTIVE

The present study aims to identify potential safety signals of chloroquine (CQ) and hydroxychloroquine (HCQ), over the period preceding their repurpose as COVID-19 treatment options, through the analysis of safety data retrieved from the FDA Adverse Event Reporting System (FAERS) pharmacovigilance database.

MATERIALS AND METHODS

We performed a disproportionality analysis of FAERS data between the first quarter of 2004 and December 2019 using the OpenVigil2.1-MedDRA software. Disproportionality was quantified using the reporting odds ratio (ROR) and its 95% confidence interval (CIs). The reported mortality of CQ and HCQ was also investigated.

RESULTS

The dataset contained 6,635,356 reports. Comparison of the RORs revealed significant differences between CQ and HCQ for the following adverse events: cardiomyopathy, cardiac arrhythmias, retinal disorders, corneal disorders, hearing disorders, headache, hepatic disorders, severe cutaneous reactions, musculoskeletal disorders, and cytopenia. Only CQ was associated with psychotic disorders, suicide, self-injury, convulsions, peripheral neuropathy, and decreased appetite. In multivariable logistic regression, death was more frequently associated with CQ use, advanced age, male sex, co-reported suicide and self-injury, cardiomyopathy, cardiac arrhythmias, and decreased appetite.

CONCLUSIONS

Our results confirm previously published evidence and suggest that HCQ has a safer clinical profile compared to CQ, and thus could serve as the drug of choice for future therapeutic purposes.

Synthesis of Recommendations From 25 Countries and 31 Oncology Societies: How to Navigate Through Covid-19 Labyrinth

Introduction

Pandemic COVID-19 is an unexpected challenge for the oncological community, indicating potential detrimental effects on cancer patients. Our aim was to summarize the converging key points providing a general guidance in order to support decision making, pertaining to the oncologic care in the middle of a global outbreak.

Methods

We did an international online search in twenty five countries that have managed a surge in cancer patient numbers. We collected the recommendations from thirty one medical oncology societies.

Results

By synthesizing guidelines for a) oncology service delivery adjustments, b) general and specific treatment adaptations, and c) discrepancies from guidelines comparison, we present a clinical synopsis with the forty more crucial statements. A Covid-19 risk stratification base was also created in order to obtain a quick, objective patient assessment and a risk-benefit evaluation on a case-by-case basis.

Conclusions

In an attempt to face these complex needs and due to limited understanding of COVID-19, a variability of recommendations based on general epidemiological and infectious disease principles rather than definite cancer-related evidence has evolved. Additionally, the absence of an effective treatment or vaccine requires the development of cancer management guidance, capitalizing on comprehensive COVID-19 oncology experience globally.

Immunomodulatory effects of vitamin D: implications for GVHD

GVHD remains a major source of morbidity and mortality after allogeneic BMT. GVHD is mediated by alloreactive T cells derived from the hematopoietic graft that target host tissues. Pre-clinical models have shown that presentation of alloantigens by host DCs results in the activation of donor-derived T cells that mediate GVHD. Strategies that interfere with the Ag-presenting capacity of DCs after allogeneic transplantation may decrease the risk of developing GVHD. Vitamin D is a hormone essential for calcium metabolism that shows immunomodulatory properties. We showed that correction of vitamin D deficiency appeared to mitigate manifestations of GVHD. In pre-clinical studies, we have shown that vitamin D inhibits DC maturation, polarizes T-cell populations toward the expression of Th2 as compared with Th1 cytokines, and blunts allogeneic T-cell proliferation in response to DC stimulation. Exposure to vitamin D resulted in increased expression of IDO, an enzyme responsible for tryptophan metabolism that is upregulated in tolerizing DCs. These data suggest that exposure to vitamin D results in immature DC populations that bias toward tolerizing rather than stimulatory T-cell populations. Vitamin D may therefore have a role in the prevention of GVHD.

Predictive value of EGFR mRNA levels assessed by quantitative RT-PCR in primary tumors of patients treated with cetuximab for metastatic colorectal cancer

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Background: The epidermal growth factor receptor (EGFR) protein is the nominal target of the monoclonal therapeutic antibody cetuximab. Yet, repeated failure of EGFR immunohistochemistry (IHC) in predicting treatment outcome has questioned its value in colorectal cancer (CRC). Therefore search for a valid molecular predictor of cetuximab efficacy is highly justified. Methods: 64 CRC patients were treated with standard chemotherapy plus cetuximab in the metastatic setting. RNA was isolated from fixed tumor tissue samples employing an experimental method based on magnetic beads from Siemens Medical Solutions Diagnostics, followed by kinetic one-step RT-PCR for EGFR, HER-2, HER-3, and HER-4 analysis. EGFR protein levels were also assessed by IHC in 62 of the patients, using the 31G7 clone of the mouse monoclonal antibody (Zymed). Slides scored 1+, 2+ and 3+ were considered EGFR protein positive. Results: After a median follow-up of 17 months, median survival was 15.1 months, while median time to disease progression (TTP) was 6.6 months. For the RT-PCR results an objective cut-off at the 2nd quartile (median) for the HER family was chosen. EGFR RNA levels above the median value, demonstrated predictive value in terms of a prolonged TTP (9.3 vs. 5.5 months, p=0.017). No difference was found in terms of survival (24.6 vs. 12.6 months, p=0.106). EGRF assessed by IHC and the rest of the HER family markers assessed by RT-PCR failed to predict TTP outcome or survival. Finally, no agreement was found between the IHC and RT-PCR methods when assessing EGFR. Conclusions: The results of this retrospective study show a predictive value of EGFR RNA levels assessed by RT-PCR on TTP, as opposed to EGFR protein levels. Prospective validation studies are needed to prove if this biomarker is the missing molecular predictor of response to cetuximab.

No significant financial relationships to disclose.

Helper T cell anergy: from biochemistry to cancer pathophysiology and therapeutics

Tolerance in vivo and its in vitro counterpart, anergy, are defined as the state in which helper T lymphocytes are alive but incapable of producing IL-2 and expanding in response to optimal antigenic stimulation. Anergy is induced when the T cell receptor (TCR) is engaged by antigen in the absence of costimulation or IL-2. This leads to unique intracellular signaling events that stand in contrast to those triggered by coligation of the TCR and costimulatory receptors. Specifically, anergy is characterized by lack of activation of lck, ZAP 70, Ras, ERK, JNK, AP-1, and NF-AT. In contrast, anergizing stimuli appear to activate the protein tyrosine kinase fyn, increase intracellular calcium levels, and activate Rap1. Moreover, anergizing TCR signals result in increased intracellular concentrations of the second messenger cAMP. This second messenger upregulates the cyclin-dependent kinase (cdk) inhibitor p27kip1, sequestering cyclin D2-cdk4, and cyclin E/cdk2 complexes and preventing progression of T cells through the G1 restriction point of the cell cycle. In contrast, costimulation through CD28 prevents p27kip1 accumulation by decreasing the levels of intracellular cAMP and promotes p27kip1 down-regulation due to direct degradation of the protein via the ubiquitin-proteasome pathway. Subsequent autocrine action of IL-2 leads to further degradation of p27kip1 and entry into S phase. Understanding the biochemical and molecular basis of T cell anergy will allow the development of new assays to evaluate the immune status of patients in a variety of clinical settings in which tolerance has an important role, including cancer, autoimmune diseases, and organ transplantation. Precise understanding of these biochemical and molecular events is necessary in order to develop novel treatment strategies against cancer. One of the mechanisms by which tumors down-regulate the immune system is through the anergizing inactivation of helper T lymphocytes, resulting in the absence of T cell help to tumor-specific CTLs. Although T-cells specific for tumor associated antigens are detected in cancer patients they often are unresponsive. Reversal of the defects that block the cell cycle progression is mandatory for clonal expansion of tumor specific T cells during the administration of tumor vaccines. Reversal of the anergic state of tumor specific T cells is also critical for the sufficient expansion of such T cells ex vivo for adoptive immunotherapy. On the other hand, understanding the molecular mechanisms of anergy will greatly improve our ability to design novel clinical therapeutic approaches to induce antigen-specific tolerance and prevent graft rejection and graft-versus-host disease. Such treatment approaches will allow transplantation of bone marrow and solid organs between individuals with increasing HLA disparity and therefore expand the donor pool, enable reduction in the need for nonspecific immunosuppression, minimize the toxicity of chemotherapy, and reduce the risk of opportunistic infections.

Tob is a negative regulator of activation that is expressed in anergic and quiescent T cells

During a search for genes that maintain T cell quiescence, we determined that Tob, a member of an anti-proliferative gene family, was highly expressed in anergic T cell clones. Tob was also expressed in unstimulated peripheral blood T lymphocytes and down-regulated during activation. Forced expression of Tob inhibited T cell proliferation and transcription of cytokines and cyclins. In contrast, suppression of Tob with an antisense oligonucleotide augmented CD3-mediated responses and abrogated the requirement of costimulation for maximal proliferation and cytokine secretion. Tob associated with Smad2 and Smad4 and enhanced Smad DNA-binding. The inhibitory effect of Tob on interleukin 2 (IL-2) transcription was not mediated by blockade of NFAT, AP-1 or NF-kappaB transactivation but by enhancement of Smad binding on the -105 negative regulatory element of the IL-2 promoter. Thus, T cell quiescence is an actively maintained phenotype that must be suppressed for T cell activation to occur.