Drug-induced progressive multifocal leukoencephalopathy: a case/noncase study in the French pharmacovigilance database

Sensitivity and specificity in signal detection with the reporting odds ratio and the information component

PURPOSE

As measures of association between an adverse drug reaction (ADR) and exposure to a drug the reporting odds ratio (ROR) and the information component (IC) can be used. We sought to test the reliability of signal detection with these.

METHODS

We simulated ADR counts as binomially distributed random numbers for different expected ADR frequencies and theoretical reporting odds ratios (RORs). We then calculated the empirical IC and the empirical ROR and their confidence intervals. The rate of signals that was detected despite a theoretical ROR of 1 represented the false positive rate, and represented the sensitivity if the ROR was >1.

RESULTS

For expected case counts below 1 the false positive rate oscillates from 0.01 to 0.1 even though 0.025 were intended. Even beyond expected case counts of 5 oscillations can cover a range of 0.018 to 0.035. The first n oscillations with the largest amplitude are eliminated if a minimum case count of n is required. To detect an ROR of 2 with a sensitivity of 0.8, a minimum of 12 expected ADRs are required. In contrast, 2 expected ADRs suffice to detect an ROR of 4.

CONCLUSION

Summaries of measures for disproportionality should include the expected number of cases in the group of interest if a signal was detected. If no signal was detected the sensitivity for the detection of a representative ROR or the minimum ROR that could be detected with probability 0.8 should be reported.

Nationwide Laboratory Surveillance of Progressive Multifocal Leukoencephalopathy in Japan: Fiscal Years 2011-2020

Progressive multifocal leukoencephalopathy (PML) is a devastating demyelinating disease caused by JC virus (JCV), predominantly affecting patients with impaired cellular immunity. PML is a non-reportable disease with a few exceptions, making national surveillance difficult. In Japan, polymerase chain reaction (PCR) testing for JCV in the cerebrospinal fluid (CSF) is performed at the National Institute of Infectious Diseases to support PML diagnosis. To clarify the overall profile of PML in Japan, patient data provided at the time of CSF-JCV testing over 10 years (FY2011-2020) were analyzed. PCR testing for 1537 new suspected PML cases was conducted, and 288 (18.7%) patients tested positive for CSF-JCV. An analysis of the clinical information on all individuals tested revealed characteristics of PML cases, including the geographic distribution, age and sex patterns, and CSF-JCV-positivity rates among the study subjects for each type of underlying condition. During the last five years of the study period, a surveillance system utilizing ultrasensitive PCR testing and widespread clinical attention to PML led to the detection of CSF-JCV in the earlier stages of the disease. The results of this study will provide valuable information not only for PML diagnosis, but also for the treatment of PML-predisposing conditions.

Progressive multifocal leukoencephalopathy in multiple myeloma. A literature review and lessons to learn

Progressive multifocal leukoencephalopathy (PML) is a rare opportunistic infection with high mortality rate usually seen in the context of immunosuppression. Although cases have been reported largely in patients with HIV/AIDS, following the use of monoclonal antibodies and occasionally in haematological malignancies, there is no review to date of patients with smouldering or treated myeloma who developed PML. Here, we conducted a literature search of PML cases in patients with multiple myeloma (MM), analyse patient and disease characteristics and describe the possible mechanisms that could lead to the development of PML. The lack of data and case reports until 2010 may indicate that PML in MM is underdiagnosed. Simultaneously, with an expanding field of new therapeutic options, patients with MM live longer, albeit continually immunosuppressed, and at risk of opportunistic infections. Emerging new treatments for PML in the horizon render the need to look out for this complication mandatory, and more case reports are needed to enrich our knowledge in this field.

Drug-induced hearing loss: a case/non-case study in the French pharmacovigilance database

Hearing loss is defined as a decrease in the ability to perceive sounds which can occur suddenly or gradually and affects one ear or both. It is related to various etiologies, in particular drugs. The identification of all drugs that could be associated with hearing loss is essential for the patients' life quality. The objective of our study was to identify signals of hearing loss involving drugs approved in the last 20 years. The occurrence in association with drugs known for their ototoxicity was also analyzed. We used a case/non-case method in the French Pharmacovigilance Database (FPVD). The cases were reports of hearing loss in the FPVD between January 2007 and August 2017. Non-cases were all reports over the same period. We calculated the reporting odds ratio (ROR) with 95% confidence intervals. Among the 555 reports of hearing loss, significant RORs were found for 68 drugs. The main therapeutic classes implicated were antineoplastic agents (n = 240), systemic anti-infective agents (n = 182), immunosuppressants (n = 42) loop diuretics (n = 26), and salicylate analgesics (n = 26). We found signals of hearing loss with azacitidine, vaccines and nevirapine, immunosuppressants such as leflunomide, and biotherapies such as panitumumab and vandetanib. Prescribers should be informed about the potential associations with all these drugs. The role of the pathology itself and the known ototoxic drugs that can be associated do not allow to conclude definitively. Audiograms for the early detection of hearing loss induced by drugs known to be ototoxic are rarely carried out. Preventive treatments exist and must be considered.

Natalizumab-associated Progressive Multifocal Leukoencephalopathy in Patients with Multiple Sclerosis: A Mini Review

Progressive multifocal leukoencephalopathy is a fatal demyelinating disease caused by the John Cunningham virus. It causes white matter inflammation in multiple areas of the brain. Although rare, it has been known to occur in patients with immunodeficiency states and those taking chronic immunosuppressive medications for diseases such as multiple sclerosis and psoriasis. In this article, we will discuss about the drug-induced progressive multifocal encephalopathy and its diagnosis and management in patients taking natalizumab and other disease-modifying therapies among patients with multiple sclerosis.

What Is the Risk of Progressive Multifocal Leukoencephalopathy in Patients With Ulcerative Colitis or Crohn's Disease Treated With Vedolizumab?

BACKGROUND

Progressive multifocal leukoencephalopathy is a serious condition linked to certain diseases and immunosuppressant therapies, including the α4 integrin antagonist natalizumab. No cases have been reported to date with vedolizumab, a selective antagonist of the α4β7 integrin expressed on gut-homing lymphocytes. This analysis aimed to describe the current and future expected occurrence of progressive multifocal leukoencephalopathy with vedolizumab use, were the risk the same as in other populations in which this disease has been studied.

METHODS

The expected number of vedolizumab-associated progressive multifocal leukoencephalopathy cases was estimated up to May 19, 2016, and modeled up to 2034. These estimates were based on the cumulative exposure to the drug, assuming an equivalent risk to that of patients treated with natalizumab or those from other reference populations where progressive multifocal leukoencephalopathy has been examined. Future cases were modeled based on similar risks and projected sales.

RESULTS

The cumulative vedolizumab exposure was estimated at 54,619 patient-years, with a 95% confidence interval of 0.0 to 6.75 cases per 100,000 patient-years. An estimated 30.2 (95% confidence interval, 19.4-40.9) cases of progressive multifocal leukoencephalopathy would have occurred if vedolizumab had the same risk as that of natalizumab. There would be a 50% chance of the first case occurring by 2018, assuming an equivalent risk to the general population.

CONCLUSIONS

These analyses indicate that the risk of progressive multifocal leukoencephalopathy with vedolizumab is small, and unlikely to be above 6.75 cases per 100,000 patient-years.

Progressive multifocal leukoencephalopathy and rheumatoid arthritis treatments

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nervous system due to reactivation of the JC virus (JCV). PML is extremely uncommon despite the high prevalence of the virus in the general population. No specific treatment is available, and the prognosis is bleak. The diagnosis is based on brain imaging findings, detection of the JCV genome in cerebrospinal fluid samples and, in some cases, histological studies of the brain lesions. The pathophysiological mechanisms that drive the development of PML are incompletely understood. However, a consistent feature is the presence of a predisposing factor, most notably immunosuppression. The risk of developing PML varies with the underlying disease (e.g., HIV infection or autoimmune disease) and with the drugs used to treat them. Biologics have been ranked according to the risk of PML during their use. Natalizumab, a monoclonal antibody given to treat multiple sclerosis, is among the drugs associated with a high risk of PML. Patients given natalizumab are now closely monitored based on anti-JCV antibody titers and index values. In rheumatology, the expanding use of biologics has led to an increase in cases of PML, with rituximab being associated with the highest risk. Given the absence of specific recommendations, exhaustive registries and postmarketing observational studies are urgently needed to gauge the risk of PML according to the underlying disease and drug treatments, with the goal of defining optimal monitoring protocols.