Drug-induced progressive multifocal leukoencephalopathy: Lessons learned from contrasting natalizumab and rituximab

Is routine laboratory testing in healthy young patients taking isotretinoin necessary: a critically appraised topic

CLINICAL QUESTION

Is monitoring of liver function, lipids and full blood count necessary in healthy people taking isotretinoin?

BACKGROUND

Routine blood testing was recommended in the original licence for Roaccutane™ (isotretinoin) in 1983. In recent years, less frequent monitoring has been suggested by various authors.

DATA SOURCES

We performed four individual systematic searches of the MEDLINE database, via PubMed, from origin to 2 May 2021, supplemented by a hand search of all references in the identified papers.

STUDY SELECTION

Inclusion criteria were any description of clinical symptoms, laboratory abnormalities and/or physical findings, and any paper that explicitly described the patients as asymptomatic, during treatment with oral isotretinoin.

DATA EXTRACTION

Two independent reviewers (J.A. and D.J.) assessed articles for eligibility of inclusion. Evaluation of the data was done also by two of the authors (A.A., D.J. and J.A.) for each section, with the aim to use the presented evidence including guidelines, databases, case series, case reports, cohort studies and randomized clinical trials to delineate the clinical presentation and frequency of adverse events that might be amenable to laboratory monitoring.

RESULTS

We identified 407 papers in our searches and reviewed 125 papers in four sections. Overall, reported adverse events were very rare (< 1 in 10 000) and were either idiosyncratic or not preventable by monitoring, accompanied by symptoms, or seen in identifiable predisposed individuals who might benefit from monitoring because of pre-existing conditions.

RECOMMENDATION FOR CLINICAL CARE

We could not find evidence to support the benefit of monitoring to detect adverse events. We suggest that in healthy young people laboratory monitoring for oral isotretinoin is unnecessary and risks detecting nonserious biochemical abnormalities. However, we recognize that new information about adverse events may change that recommendation.

Long-Term Remission With Low-Dose Rituximab in Myasthenia Gravis: A Retrospective Study

OBJETIVE

Rituximab (RTX) is a therapeutic option, for patients with myasthenia gravis (MG) not responding to conventional immunosuppressive treatment. In this cohort, we evaluated long-term efficacy of RTX in the treatment of refractory generalized MG.

METHODS

A retrospective study was performed in adult patients with refractory generalized MG and at least 24 months of follow-up, between January/2015 and October/2021. The Myasthenia Gravis Status and Treatment Intensity Score was used to assess outcomes, and CD19/CD20+ B-cell counts were monitored.

RESULTS

Sixteen patients with MG (8 antiacetylcholine receptor+ and 8 muscle-specific antikinase+; mean age 45.5 ± 16.2 years) treated with low-dose RTX protocols were included. CD19/CD20 levels remained undetectable 12 months after induction, and no new relapses were observed during follow-up.

CONCLUSIONS

Low-dose RTX infusions were sufficient to achieve undetectable CD19/20 cell counts and sustained clinical remission. In low and middle-income countries, the impact of low-dose RTX therapy represents a paradigm shift in decision-making for long-term treatment.

Adverse Drug Reactions with Drugs Used in Multiple Sclerosis: An Analysis from the Italian Pharmacovigilance Database

Given the importance of inflammation at the onset of multiple sclerosis (MS), therapy is mainly based on the use of anti-inflammatory drugs including disease modifying therapies (DMTs). Considering the recent approval of some DMTs, pharmacovigilance becomes a fundamental tool for the acquisition of new safety data. The aim of the study was to analyze adverse drug reactions (ADRs) related to the use of drugs approved for MS. All national publicly-available aggregated ADR reports recorded from 2002 to 2020 into the Reports of Adverse Reactions of Medicines (RAM) system and all complete Sicilian data reported into the Italian spontaneous reporting system (SRS) database having as suspected drugs interferon β-1a (IFN β-1a), interferon β-1b (IFN β-1b), peginterferon β-1a (PEG-IFN β-1a), glatiramer acetate (GA), natalizumab (NTZ), fingolimod (FNG), teriflunomide (TRF), dimethyl fumarate (DMF), alemtuzumab (Alem), ocrelizumab (OCZ), or cladribine (Cladr), were collected. Descriptive analyses of national, publicly-available aggregated data and full-access regional data were performed to assess demographic characteristics and drug-related variables followed by a more in-depth analysis of all Sicilian ADRs with a case-by-case assessment and a disproportionality analysis of unexpected ADRs. A total of 13,880 national reports have been collected from 2002 to 2020: they were mainly not serious ADRs (67.9% vs. 26.1%) and related to females (71.7% vs. 26.3%) in the age group 18–65 years (76.5%). The most reported ADRs were general and administration site conditions (n = 6,565; 47.3%), followed by nervous (n = 3,090; 22.3%), skin (n = 2,763; 19.9%) and blood disorders (n = 2,180; 15.7%). Some unexpected Sicilian ADRs were shown, including dyslipidemia for FNG (n = 10; ROR 28.5, CI 14.3–59.6), NTZ (n = 5; 10.3, 4.1–25.8), and IFN β-1a (n = 4; 8.7, 3.1–24.1), abortion and alopecia for NTZ (n = 9; 208.1, 73.4–590.1; n = 3; 4.9, 1.5–15.7), and vitamin D deficiency for GA (n = 3; 121.2, 30.9–475.3). Moreover, breast cancer with DMF (n = 4, 62.8, 20.5–191.9) and hypothyroidism with Cladr (n = 3; 89.2, 25.9–307.5) were also unexpected. The reporting of drugs-related ADRs in MS were mostly reported in the literature, but some unknown ADRs were also found. However, further studies are necessary to increase the awareness about the safety profiles of new drugs on the market.

The 5-year Tysabri global observational program in safety (TYGRIS) study confirms the long-term safety profile of natalizumab treatment in multiple sclerosis

BACKGROUND

Natalizumab is an effective treatment for multiple sclerosis (MS) and has a well-characterized safety profile, with more than 10 years of postmarketing experience. TYGRIS was a 5-year observational cohort study designed to obtain long-term safety data in natalizumab-treated MS patients. We examined the incidence and pattern of serious adverse events (SAEs) in this large postmarketing sample of natalizumab-treated patients.

METHODS

Investigators reported SAEs in natalizumab-treated patients. Malignancy incidence rates were compared with rates in the general population using external databases.

RESULTS

Of 6508 enrolled patients, 4938 (75.9%) completed the study. SAEs occurring in more than 0.5% of patients included urinary tract infection (n = 50; 0.8%), pneumonia (n = 46; 0.7%), progressive multifocal leukoencephalopathy (PML; n = 44; 0.7%), and immune reconstitution inflammatory syndrome (n = 44; 0.7%). Fifty-five patients (0.9%) experienced treatment-emergent serious opportunistic infections, 44 of which were PML. Two patients with PML died. The overall malignancy incidence rate was 449.0 per 100,000 patient-years (95% confidence interval [CI], 375.1-533.1). With few exceptions, incidence rates for individual malignancies had 95% CIs encompassing incidence rates in the general population. Hepatotoxic events occurred in 6 patients; 4 patients had evidence of alternative cause or confounders. Of 96 fatal events, investigators considered 81 unrelated or unlikely to be related to treatment and 5 related or possibly related; causality was not provided for 10.

CONCLUSION

Data from this large, long-term study indicate that the nature, character, and frequency of SAEs in real-world settings are consistent with natalizumab's known safety profile. (Funded by Biogen; ClinicalTrials.gov identifiers: NCT00477113 and NCT00483847.).

Risk of Progressive Multifocal Leukoencephalopathy in the Combination Antiretroviral Therapy Era in the French Hospital Database on Human Immunodeficiency Virus (ANRS-C4)

Background

Risk factors for progressive multifocal leukoencephalopathy (PML) in individuals with human immunodeficiency virus (HIV) infection are poorly documented in the era of combination antiretroviral therapy (cART).

Methods

We studied HIV-1-infected individuals aged ≥15 years who had no history of PML and were prospectively followed up between 1997 and 2011 in the French Hospital Database on HIV (FHDH-ANRS CO4) cohort. Cox models were used to calculate adjusted hazard ratios (HRs), focusing on sub-Saharan origin, suggested to be protective, and recent cART initiation, potentially associated with an increased risk of PML.

Results

PML developed in 555 individuals, in 57 during the first 6 months of cART. From 1997-2000 to 2009-2011, the incidence fell from 1.15 (95% confidence interval [CI], .98-1.31) to 0.49 (.37-.61) per 1000 person-years. Sub-Saharan African origin had no clear influence (HR, 0.80; 95% CI, .58-1.11). Compared with men who have sex with men, injection drug users (IDUs) were at higher risk (HR, 1.80 [95% CI, 1.32-2.45] for male and 1.68 [1.13-2.48] for female IDUs). When IDUs were excluded, hepatitis C virus seropositivity was associated with an increased risk (HR, 1.40; 95% CI, 1.02-1.93). Compared with no cART initiation, initiation <6 months previously was associated with PML onset (HR, 4.91; 95% CI, 2.42-9.95).

Conclusions

Recent cART initiation is associated with an increased risk of PML, as are injection drug use and hepatitis C virus seropositivity. Sub-Saharan African origin had no protective effect.

Progressive multifocal leukoencephalopathy secondary to hepatitis C virus infection-related T-cell lymphopenia

Progressive multifocal leukoencephalopathy (PML) is an uncommon neurological condition known to occur in the setting of T-cell immune suppression. We report a case of hepatitis C virus (HCV) infection-related T-cell lymphopenia manifesting as PML. HCV treatment and transient viral suppression resulted in immunological recovery with clinical stabilisation.

Treatment of Myasthenia Gravis

With specialized care, patients with myasthenia gravis can have very good outcomes. The mainstays of treatment are acetylcholinesterase inhibitors, and immunosuppressive and immunomodulatory therapies. There is good evidence thymectomy is beneficial in thymomatous and nonthymomatous disease. Nearly all of the drugs used for MG are considered "off-label." The 2 exceptions are acetylcholinesterase inhibitors and complement inhibition with eculizumab, which was recently approved by the US Food and Drug Administration for myasthenia gravis. This article reviews the evidence base and provides a framework for the treatment of myasthenia gravis, highlighting recent additions to the literature.

Identifiability of Biologicals in Adverse Drug Reaction Reports Received From European Clinical Practice

Biologicals are established treatment options that require pharmacovigilance adapted to their specific nature, including the need for products to be identifiable up to the specific manufacturer in reports of adverse drug reactions (ADRs). This study explored the identifiability of 10 classes of similar and related biologicals up to the level of the manufacturer in ADR reports received from European clinical practice between 2011 and June 2016. Adequate identifiers were reported for 96.7% of the suspected biologicals, ranging from 89.5% for filgrastim to 99.8% for interferon beta‐1a. The product identifiability remained consistently high over time for classes of biologicals for which biosimilars were introduced during follow‐up. The overall batch traceability was, however, only ensured for 20.5% of the suspected biologicals and needs further improvement. This study shows that the European system for identification of ADRs to the level of the manufacturer is robust, allowing for the timely detection of potential product‐specific safety signals for biologicals.

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.

Statistical Practices of Safety Monitoring: An Industry Survey

The Biopharmaceutical Section of the American Statistical Association (ASA) formed a Safety Monitoring Working Group to strengthen collaborations between biostatisticians and safety scientists. The task began by surveying current needs and practices regarding available statistical safety tools and methods, regulatory guidance, and processes needed to support their implementation. The goal is for biostatisticians to become fully engaged safety team members by having the necessary safety skill set including appropriate methodology, regulatory guidance and access to appropriate tools. In this publication, we will discuss our survey results that reveal current practices at 22 pharmaceutical companies and demonstrate how the survey instrument can be used to map an action plan for meeting the demand for improved quantitative safety monitoring.

Neuro-ophthalmic side effects of molecularly targeted cancer drugs

The past two decades has been an amazing time in the advancement of cancer treatment. Molecularly targeted therapy is a concept in which specific cellular molecules (overexpressed, mutationally activated, or selectively expressed proteins) are manipulated in an advantageous manner to decrease the transformation, proliferation, and/or survival of cancer cells. In addition, increased knowledge of the role of the immune system in carcinogenesis has led to the development of immune checkpoint inhibitors to restore and enhance cellular-mediated antitumor immunity. The United States Food and Drug Administration approval of the chimeric monoclonal antibody (mAb) rituximab in 1997 for the treatment of B cell non-Hodgkin lymphoma ushered in a new era of targeted therapy for cancer. A year later, trastuzumab, a humanized mAb, was approved for patients with breast cancer. In 2001, imatinib was the first small-molecule kinase inhibitor approved. The approval of ipilimumab-the first in class immune checkpoint inhibitor-in 2011 serves as a landmark period of time in the resurgence of immunotherapy for cancer. Despite the notion that increased tumor specificity results in decreased complications, toxicity remains a major hurdle in the development and implementation of many of the targeted anticancer drugs. This article will provide an overview of the current cellular and immunological understanding of cancer pathogenesis-the foundation upon which molecularly targeted therapies were developed-and a description of the ocular and neuro-ophthalmic toxicity profile of mAbs, immune checkpoint inhibitors, and small-molecule kinase inhibitors.

Unintended Immunological Consequences of Biologic Therapy

Recent advances in the understanding of immune dysregulation in autoimmune diseases have enabled the development of new monoclonal antibody-based drugs called biologics. Biologics have been used to target aberrant immune responses in many diseases, but patients with rheumatologic and other autoimmune diseases have benefited the most and improvements in outcomes have been significant. The use of biologics is not without hazard, however, as these agents block immune pathways adapted to protect the host. This has been borne out by increased rates of infections as well as induction of new autoimmune and hematologic adverse effects. As new drugs for the treatment of autoimmune conditions are entering the pipeline, it is incumbent on the practicing immunologist to understand the mechanism of these biologics and the implications of clinical use.

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

Progressive multifocal leukoencephalopathy (PML) is an often fatal demyelinating disease of the central nervous system. As effective treatment is unavailable, identification of all drugs that could be associated with PML is essential. The objective of this study was to investigate the putative association of reports of PML and drugs. We used the case/noncase method in the French PharmacoVigilance database (FPVD). Cases were reports of PML in the FPVD between January 2008 and December 2015. Noncases were all other reports during the same period. To assess the association between PML and drug intake, we calculated an adverse drug report odds ratio (ROR) with its 95% confidence interval. We have studied the delay of onset of PML for each drug concerned. Among the 101 cases of PML, 39 drugs were mentioned as suspect. The main therapeutic classes suspected with significant ROR were antineoplastic agents (n = 85), immunosuppressants (n = 67), and corticosteroids. A latent interval from the time of drug initiation to the development of PML is established: the median time to onset was 365 days (123-1095 days). The onset of PML is highly variable and differs among drug classes [from 1 to 96 months (IQR: 39.0-126)]. An association between PML and some immunosuppressant drugs was found as expected, but also with antineoplastic agents and glucocorticoids. An important delay of PML onset after stopping treatment is suspected and should alert prescribers. Prescribers but also patients should be informed about the potential associations with all these drugs. Monitoring could be necessary for many drugs to early detect PML.

Further understanding of the immunopathology of multiple sclerosis: impact on future treatments

INTRODUCTION

The understanding of the immunopathogenesis of multiple sclerosis (MS) has expanded with more research into T-cell subtypes, cytokine contributors, B-cell participation, mitochondrial dysfunction, and more. Treatment options have rapidly expanded with three relatively recent oral therapy alternatives entering the arena.

AREAS COVERED

In the following review, we discuss current mechanisms of immune dysregulation in MS, how they relate to current treatments, and the impact these findings will have on the future of therapy. Expert commentary: The efficacy of these medications and understanding their mechanisms of actions validates the immunopathogenic mechanisms thought to underlie MS. Further research has exposed new targets, while new promising therapies have shed light on new aspects into the pathophysiology of MS.

Detection of cases of progressive multifocal leukoencephalopathy associated with new biologicals and targeted cancer therapies from the FDA's adverse event reporting system

OBJECTIVE

To identify and summarize FDA's Adverse Event Reporting System (FAERS) cases of progressive multifocal leukoencephalopathy (PML) associated with biological and targeted cancer therapies (BTCT) that were approved between 2009 and 2015.

METHODS

FAERS was searched using each BTCT name as primary or secondary suspect drug and the adverse reaction of PML. Among BTCTs with >2 case reports of PML, proportional reporting ratios (PRR) and 95% confidence intervals (CI) were calculated.

RESULTS

Among 49 new BTCTs, 82 cases of PML were found for 16 drugs. Significant PRR signals were found among 7 (14.6%) BTCTs including: brentuximab (24.5, CI:14.8-40.6), ofatumumab (16.3, CI:9.6-27.4), alemtuzumab (9.9, CI:6.0-16.4), obinutuzumab (7.4, CI:2.4-22.8), ibrutinib (5.6 CI:3.0-10.5), belimumab (4.5 CI:2.3-9.0), and idelalisib (4.1, CI:1.3-12.6). Among the 82 cases with significant signals, confirmation of the diagnosis of PML using objective criteria was found in 56% of the cases. A limitation of FAERS data is that missing data are common.

CONCLUSIONS

When using BTCTs, clinicians and patients consider the risk of PML versus the therapeutic benefit, particularly when used in combination with other drugs which may cause PML, such as rituximab. It is important to recognize that PML may occur in some conditions, such as chronic lymphocytic leukemia, regardless of drug therapy.