Efficacy and Safety of Ponesimod Compared with Teriflunomide in Female Patients with Relapsing Multiple Sclerosis: Findings from the Pivotal OPTIMUM Study

Background: Multiple sclerosis (MS) is threefold more prevalent in women than men. However, sex-specific efficacy analysis for MS disease-modifying therapies is not typically performed. Methods: Post hoc analyses of data from female patients enrolled in the phase 3, double-blind OPTIMUM study of relapsing MS were carried out. Eligible adults were randomized to ponesimod 20 mg or teriflunomide 14 mg once daily for up to 108 weeks. The primary endpoint was annualized relapse rate (ARR); secondary endpoints included change in symptom domain of Fatigue Symptom and Impact Questionnaire-Relapsing Multiple Sclerosis (FSIQ-RMS) at week 108, number of combined unique active lesions (CUALs) per year on magnetic resonance imaging, and time to 12- and 24-week confirmed disability accumulation (CDA). Results: A total of 735 female patients (581 of childbearing potential) were randomized to ponesimod (n = 363, 49.4%) or teriflunomide (n = 372, 50.6%). Relative risk reduction in the ARR for ponesimod versus teriflunomide was 33.1% (mean, 0.192 vs. 0.286, respectively; p < 0.002). Mean difference in FSIQ-RMS for ponesimod versus teriflunomide was -4.34 (0.12 vs. 4.46; p = 0.002); rate ratio in CUALs per year, 0.601 (1.45 vs. 2.41; p < 0.0001), and hazard ratio for time to 12- and 24-week CDA risk estimates, 0.83 (10.7% vs. 12.9%; p = 0.38) and 0.91 (8.8% vs. 9.7%; p = 0.69), respectively. Incidence of treatment-emergent adverse events was similar between treatment groups (89.0% and 90.1%). Conclusions: Analyses demonstrate the efficacy and safety of ponesimod, versus active comparator, for women with relapsing MS, supporting data-informed decision-making for women with MS. Clinical Trial Registration Number: NCT02425644.

Headache in Multiple Sclerosis: A Narrative Review

Background: Multiple sclerosis (MS) is a chronic inflammatory demyelinating disorder of the central nervous system characterized by autoimmune-mediated damage to oligodendrocytes and subsequent myelin destruction. Clinical implications: Clinically, the disease presents with many symptoms, often evolving over time. The insidious onset of MS often manifests with non-specific symptoms (prodromal phase), which may precede a clinical diagnosis by several years. Among them, headache is a prominent early indicator, affecting a significant number of MS patients (50-60%). Results: Headache manifests as migraine or tension-type headache with a clear female predilection (female-male ratio 2-3:1). Additionally, some disease-modifying therapies in MS can also induce headache. For instance, teriflunomide, interferons, ponesimod, alemtuzumab and cladribine are associated with an increased incidence of headache. Conclusions: The present review analyzed the literature data on the relationship between headache and MS to provide clinicians with valuable insights for optimized patient management and the therapeutic decision-making process.

[Long-term efficacy and safety of divozilimab during 2-year treatment of multiple sclerosis patients in randomized double-blind placebo-controlled clinical trial BCD-132-4/MIRANTIBUS]

OBJECTIVE

To evaluate the efficacy and safety of the anti-CD20 monoclonal antibody divozilimab (DIV) used as an intravenous infusion at a dose of 500 mg every 24 weeks during 100 weeks for the treatment of patients with multiple sclerosis (MS), including relapsing-remitting multiple sclerosis (RRMS) and secondary progressive MS (SPMS) with relapses.

MATERIAL AND METHODS

The multicenter, randomized, double-blind and double-masked phase III clinical trial (CT) BCD-132-4/MIRANTIBUS (NCT05385744) included 338 adult patients with MS distributed in a 1:1 ratio into two groups: DIV 500 mg and teriflunomide (TRF) 14 mg. After screening, subjects were included in the main CT period, which consisted of two cycles of therapy over 48 weeks, then entered an additional period from weeks 49 to 100, which included three cycles of therapy. The efficacy was assessed based on the results of brain MRI and registration of data on relapses.

RESULTS

308 subjects completed 5 therapy cycles according to the study protocol. An analysis of the effectiveness of DIV therapy over 2 years showed a persistent suppression of MRI and clinical activity of the disease in comparison with TRF, which was confirmed by all the studied MRI indicators (including CUA; total number of gadolinium-enhancing (GdE) lesions on T1-weighted scans ; number of new or enlarged lesions on T2-weighted scans; lesions volume change on T2-weighted scans; change in the volume of hypointense lesions on T1-weighted scans). The use of DIV was associated with a statistically significant decrease in ARR compared to TRF (p=0.0001). The ARR in the DIV group was 0.057, in the TRF group - 0.164 with 95% confidential interval for the frequency ratio [0.202; 0.593]. The incidence of GdE lesions on T1-weighted scans in the DIV group was significantly lower than in the TRF group. The average number of such lesions was 0.0±0.08 and 1.0±4.46 in the DIV and TRF groups, respectively (p<0.0001). Progression of EDSS was detected in 18 (10.7%) and 36 (21.3%) patients in the DIV and TRF groups, respectively (p=0.0075). The proportion of patients with relapses was 11.2% (n=19) in the DIV group and 23.1% (n=39) in the TRF group (p=0.0039). In the subpopulation of patients with SPMS, no cases of increase in EDSS were detected, and not a single case of exacerbation was recorded over 2 years of using DIV. Also, DIV has shown a favorable safety profile. Among the adverse reactions (AR), infusion reactions and laboratory abnormalities, such as a decrease in the number of leukocytes, neutrophils, and lymphocytes, were most often recorded. Identified AR were expected, had mild to moderate severity, and resolved without any negative consequences.

CONCLUSION

The results of the BCD-132-4/MIRANTIBUS CT indicate a high sustained efficacy and safety of long-term use of DIV in comparison with TRF during 2 years of therapy.

Paradigm shifts in multiple sclerosis management: Implications for daily clinical practice

Multiple sclerosis (MS) is the most common chronic inflammatory neurological disease. The emergence of disease-modifying therapies (DMTs) has greatly improved disease activity control and progression of disability in MS patients. DMTs differ in their mode of action, route of administration, efficacy, and safety profiles, offering multiple options for clinicians. Personalized medicine aims at tailoring the therapeutic strategy to patients' characteristics and disease activity but also patients' needs and preferences. New therapeutic options have already changed treatment paradigms for patients with active relapsing MS (RMS). The traditional approach consists in initiating treatment with moderate-efficacy DMTs and subsequently, escalating to higher-efficacy DMTs when there is evidence of clinical and/or radiological breakthrough activity. Recent real-world studies suggest that initiation of high-efficacy DMTs from disease onset can improve long-term outcomes for RMS patients. In this article, we review different treatment strategies and discuss challenges associated with personalized therapy.

Hepatotoxicity associated with the use of teriflunomide in a patient with multiple sclerosis: A case report

RATIONALE

Teriflunomide is an inhibitor of pyrimidine synthesis available as a first-line treatment for relapsing-remitting multiple sclerosis. Drug-induced liver damage is a relevant problem in clinical practice, representing a frequent cause of treatment discontinuation. This case report describes the occurrence of liver injury, with a 33.7-fold increase in the upper limit of normality of the liver enzyme alanine aminotransferase during treatment with teriflunomide 14 mg.

PATIENT CONCERN

A 44-year-old woman receiving teriflunomide 14 mg for the treatment of multiple sclerosis presented symptoms suggestive of liver dysfunction 54 days after starting treatment. The patient had no history of using disease-modifying therapy, neither previous liver disease nor other comorbidities.

DIAGNOSTICS

The suggested diagnosis was drug-induced liver injury, classified as hepatocellular. Other possible hepatic and autoimmune etiologies were ruled out.

INTERVENTIONS

Replacement of teriflunomide treatment with glatiramer acetate and follow-up of the disease.

OUTCOMES

Signs and symptoms regressed after treatment with teriflunomide 14 mg was discontinued, with normalization of liver enzyme activity in ∼5 months. The causality assessment of the adverse drug reaction was determined by the Naranjo scaling system, resulting in probable, with a final score of 7.

CONCLUSIONS

Teriflunomide-induced liver injury in patients with multiple sclerosis is a serious adverse reaction. The report of this case contributes to updating knowledge about the safety aspects of treatment with teriflunomide and planning of monitoring strategies and patient risk management.

Teriflunomide Treatment of Multiple Sclerosis Selectively Modulates CD8 Memory T Cells

Background and Objectives

Inhibition of de novo pyrimidine synthesis in proliferating T and B lymphocytes by teriflunomide, a pharmacological inhibitor of dihydroorotate dehydrogenase (DHODH), has been shown to be an effective therapy to treat patients with MS in placebo-controlled phase 3 trials. Nevertheless, the underlying mechanism contributing to the efficacy of DHODH inhibition has been only partially elucidated. Here, we aimed to determine the impact of teriflunomide on the immune compartment in a longitudinal high-dimensional follow-up of patients with relapse-remitting MS (RRMS) treated with teriflunomide.

Methods

High-dimensional spectral flow cytometry was used to analyze the phenotype and the function of innate and adaptive immune system of patients with RRMS before and 12 months after teriflunomide treatment. In addition, we assessed the impact of teriflunomide on the migration of memory CD8 T cells in patients with RRMS, and we defined patient immune metabolic profiles.

Results

We found that 12 months of treatment with teriflunomide in patients with RRMS does not affect the B cell or CD4 T cell compartments, including regulatory TREG follicular helper TFH cell and helper TH cell subsets. In contrast, we observed a specific impact of teriflunomide on the CD8 T cell compartment, which was characterized by decreased homeostatic proliferation and reduced production of TNFα and IFNγ. Furthermore, we showed that DHODH inhibition also had a negative impact on the migratory velocity of memory CD8 T cells in patients with RRMS. Finally, we showed that the susceptibility of memory CD8 T cells to DHODH inhibition was not related to impaired metabolism.

Discussion

Overall, these findings demonstrate that the clinical efficacy of teriflunomide results partially in the specific susceptibility of memory CD8 T cells to DHODH inhibition in patients with RRMS and strengthens active roles for these T cells in the pathophysiological process of MS.

Efficacy and safety of dihydroorotate dehydrogenase (DHODH) inhibitors "leflunomide" and "teriflunomide" in Covid-19: A narrative review

Dihydroorotate dehydrogenase (DHODH) is rate-limiting enzyme in biosynthesis of pyrimidone which catalyzes the oxidation of dihydro-orotate to orotate. Orotate is utilized in the biosynthesis of uridine-monophosphate. DHODH inhibitors have shown promise as antiviral agent against Cytomegalovirus, Ebola, Influenza, Epstein Barr and Picornavirus. Anti-SARS-CoV-2 action of DHODH inhibitors are also coming up. In this review, we have reviewed the safety and efficacy of approved DHODH inhibitors (leflunomide and teriflunomide) against COVID-19. In target-centered in silico studies, leflunomide showed favorable binding to active site of MPro and spike: ACE2 interface. In artificial-intelligence/machine-learning based studies, leflunomide was among the top 50 ligands targeting spike: ACE2 interaction. Leflunomide is also found to interact with differentially regulated pathways [identified by KEGG (Kyoto Encyclopedia of Genes and Genomes) and reactome pathway analysis of host transcriptome data] in cogena based drug-repurposing studies. Based on GSEA (gene set enrichment analysis), leflunomide was found to target pathways enriched in COVID-19. In vitro, both leflunomide (EC50 41.49 ± 8.8 μmol/L) and teriflunomide (EC50 26 μmol/L) showed SARS-CoV-2 inhibition. In clinical studies, leflunomide showed significant benefit in terms of decreasing the duration of viral shredding, duration of hospital stay and severity of infection. However, no advantage was seen while combining leflunomide and IFN alpha-2a among patients with prolonged post symptomatic viral shredding. Common adverse effects of leflunomide were hyperlipidemia, leucopenia, neutropenia and liver-function alteration. Leflunomide/teriflunomide may serve as an agent of importance to achieve faster virological clearance in COVID-19, however, findings needs to be validated in bigger sized placebo controlled studies.

Ofatumumab versus Teriflunomide in Multiple Sclerosis

BACKGROUND

Ofatumumab, a subcutaneous anti-CD20 monoclonal antibody, selectively depletes B cells. Teriflunomide, an oral inhibitor of pyrimidine synthesis, reduces T-cell and B-cell activation. The relative effects of these two drugs in patients with multiple sclerosis are not known.

METHODS

In two double-blind, double-dummy, phase 3 trials, we randomly assigned patients with relapsing multiple sclerosis to receive subcutaneous ofatumumab (20 mg every 4 weeks after 20-mg loading doses at days 1, 7, and 14) or oral teriflunomide (14 mg daily) for up to 30 months. The primary end point was the annualized relapse rate. Secondary end points included disability worsening confirmed at 3 months or 6 months, disability improvement confirmed at 6 months, the number of gadolinium-enhancing lesions per T1-weighted magnetic resonance imaging (MRI) scan, the annualized rate of new or enlarging lesions on T2-weighted MRI, serum neurofilament light chain levels at month 3, and change in brain volume.

RESULTS

Overall, 946 patients were assigned to receive ofatumumab and 936 to receive teriflunomide; the median follow-up was 1.6 years. The annualized relapse rates in the ofatumumab and teriflunomide groups were 0.11 and 0.22, respectively, in trial 1 (difference, -0.11; 95% confidence interval [CI], -0.16 to -0.06; P<0.001) and 0.10 and 0.25 in trial 2 (difference, -0.15; 95% CI, -0.20 to -0.09; P<0.001). In the pooled trials, the percentage of patients with disability worsening confirmed at 3 months was 10.9% with ofatumumab and 15.0% with teriflunomide (hazard ratio, 0.66; P = 0.002); the percentage with disability worsening confirmed at 6 months was 8.1% and 12.0%, respectively (hazard ratio, 0.68; P = 0.01); and the percentage with disability improvement confirmed at 6 months was 11.0% and 8.1% (hazard ratio, 1.35; P = 0.09). The number of gadolinium-enhancing lesions per T1-weighted MRI scan, the annualized rate of lesions on T2-weighted MRI, and serum neurofilament light chain levels, but not the change in brain volume, were in the same direction as the primary end point. Injection-related reactions occurred in 20.2% in the ofatumumab group and in 15.0% in the teriflunomide group (placebo injections). Serious infections occurred in 2.5% and 1.8% of the patients in the respective groups.

CONCLUSIONS

Among patients with multiple sclerosis, ofatumumab was associated with lower annualized relapse rates than teriflunomide. (Funded by Novartis; ASCLEPIOS I and II ClinicalTrials.gov numbers, NCT02792218 and NCT02792231.).

Enantiomeric impacts of two amide chiral herbicides on Echinochloa crus-galli physiology and gene transcription

Echinochloa crus-galli is one of the most noxious weeds in the world and causes yield losses in a variety of different field crops. Napropamide and acetochlor are herbicides commonly employed to control this weed. Both compounds are chiral, with enantiomers displaying different activities. However, it is unclear how the enantiomers of these two chiral herbicides act on different tissues of E. crus-galli. The objective of this paper is to investigate the action mechanism of napropamide and acetochlor in the roots and shoots of E. crus-galli. R‑enantiomers were found to be more active than either the racemates or S-enantiomers on the weed. The content of chlorophyll was not significantly affected by treatment with either enantiomer. The impacts on the activity for the oxidative stress enzymes, except catalase (CAT), showed that both napropamide and acetochlor enantiomers could induce oxidative stress. Furthermore, R‑enantiomers caused greater oxidative damage. Enhanced glutathione-S-transferase (GST) activity and expression of GST genes suggested both EcGSTF1 and EcGSTZ1 were present in the roots and shoots, and this will be helpful for detoxification. The changes in both the roots and shoots revealed the two herbicides displayed tissue selectivity in E. crus-galli. These results enable a better understanding on the mechanism of action for napropamide and acetochlor enantiomers on different tissues, including the shoots and roots in E. crus-galli.

Pregnancy Outcomes in Men and Women Treated With Teriflunomide. A Population-Based Nationwide Danish Register Study

Background: The majority of persons diagnosed with multiple sclerosis (MS) experience their first MS symptoms in the reproductive age. Teriflunomide (TFL, Aubagio), was first released in Denmark for relapsing-remitting MS in December 2013. TFL treatment is contraindicated in women of childbearing potential who are not using reliable contraception. TFL can be transmitted via semen and a low risk of male-mediated embryo-fetal toxicity is described. Objective: To report pregnancy outcomes of TFL-treated women and partners to TFL-treated men: gestation week. Methods: Prospective cohort study comparing pregnancy outcomes of TFL-treated men and women, matched on age at conception, 1:4 with controls from the general population. Data on TFL-treated patients treated 1st of January 2014-31st of December 2016 for at least 30 consecutive days prior to conception, and with conception occurring latest 2 years after treatment discontinuation were extracted from The Danish Multiple Sclerosis Registry and merged with several national reproductive registries. Logistic regression was used to analyse the association between TFL exposure and any adverse event. Results: A total of 31 pregnancies were recorded, 13 women and 18 of partners to a TFL-treated man. All 18 partners of TFL-treated men completed their pregnancies: livebirth (18), gestation time >37 weeks (17), gestation time 33-36 weeks (1), normal birth weight (18), spontaneous and elective abortion (0), congenital malformation (plagiocephali) (1), normal delivery (14), induced delivery (2), cesarean section (2), Apgar score ≥7 (18). Among the 13 pregnancies in women exposed to TFL: elective abortion (11), spontaneous abortion (0), livebirth (2), gestation time >37 weeks (2), normal birth weight (2), congenital malformations (0), normal delivery (1), induced delivery (1), Apgar score ≥7 (2). The TFL group was associated with a 22% reduction in the odds of any adverse event relative to controls, although this association was not significant (OR 0.78; 95% CI 0.16-3.72, p = 0.753). Conclusion: Pregnancy outcomes were consistent with those of the general population. The malformation reported of the partner to a TFL-treated man is comparable to the rate of plagiocephaly reported in Denmark.

Metabolome disruption of pregnant rats and their offspring resulting from repeated exposure to a pesticide mixture representative of environmental contamination in Brittany

The use of pesticides exposes humans to numerous harmful molecules. Exposure in early-life may be responsible for adverse effects in later life. This study aimed to assess the metabolic modifications induced in pregnant rats and their offspring by a pesticide mixture representative of human exposure. Ten pregnant rats were exposed to a mixture of eight pesticides: acetochlor (246 μg/kg bw/d) + bromoxynil (12 μg/kg bw/d) + carbofuran (22.5 μg/kg bw/d) + chlormequat (35 μg/kg bw/d) + ethephon (22.5 μg/kg bw/d) + fenpropimorph (15.5 μg/kg bw/d) + glyphosate (12 μg/kg bw/d) + imidacloprid (12.5 μg/kg bw/d) representing the main environmental pesticide exposure in Brittany (France) in 2004. Another group of 10 pregnant rats served as controls. Females were fed ad libitum from early pregnancy, which is from gestational day (GD) 4 to GD 21. Urine samples were collected at GD 15. At the end of the exposure, mothers and pups were euthanized and blood, liver, and brain samples collected. 1H NMR-based metabolomics and GC-FID analyses were performed and PCA and PLS-DA used to discriminate between control and exposed groups. Metabolites for which the levels were significantly modified were then identified using the Kruskal-Wallis test, and p-values were adjusted for multiple testing correction using the False Discovery Rate. The metabolomics analysis revealed many differences between dams of the two groups, especially in the plasma, liver and brain. The modified metabolites are involved in TCA cycle, energy production and storage, lipid and carbohydrate metabolism, and amino-acid metabolism. These modifications suggest that the pesticide mixture may induce oxidative stress associated with mitochondrial dysfunction and the impairment of glucose and lipid metabolism. These observations may reflect liver dysfunction with increased relative liver weight and total lipid content. Similar findings were observed for glucose and energy metabolism in the liver of the offspring, and oxidative stress was also suggested in the brains of male offspring.

Treatment with disease-modifying drugs for people with a first clinical attack suggestive of multiple sclerosis

BACKGROUND

The treatment of multiple sclerosis has changed over the last 20 years. The advent of disease-modifying drugs in the mid-1990s heralded a period of rapid progress in the understanding and management of multiple sclerosis. With the support of magnetic resonance imaging early diagnosis is possible, enabling treatment initiation at the time of the first clinical attack. As most of the disease-modifying drugs are associated with adverse events, patients and clinicians need to weigh the benefit and safety of the various early treatment options before taking informed decisions.

OBJECTIVES

1. to estimate the benefit and safety of disease-modifying drugs that have been evaluated in all studies (randomised or non-randomised) for the treatment of a first clinical attack suggestive of MS compared either with placebo or no treatment;2. to assess the relative efficacy and safety of disease-modifying drugs according to their benefit and safety;3. to estimate the benefit and safety of disease-modifying drugs that have been evaluated in all studies (randomised or non-randomised) for treatment started after a first attack ('early treatment') compared with treatment started after a second attack or at another later time point ('delayed treatment').

SEARCH METHODS

We searched the Cochrane Multiple Sclerosis and Rare Diseases of the CNS Group Trials Register, MEDLINE, Embase, CINAHL, LILACS, clinicaltrials.gov, the WHO trials registry, and US Food and Drug Administration (FDA) reports, and searched for unpublished studies (until December 2016).

SELECTION CRITERIA

We included randomised and observational studies that evaluated one or more drugs as monotherapy in adult participants with a first clinical attack suggestive of MS. We considered evidence on alemtuzumab, azathioprine, cladribine, daclizumab, dimethyl fumarate, fingolimod, glatiramer acetate, immunoglobulins, interferon beta-1b, interferon beta-1a (Rebif®, Avonex®), laquinimod, mitoxantrone, natalizumab, ocrelizumab, pegylated interferon beta-1a, rituximab and teriflunomide.

DATA COLLECTION AND ANALYSIS

Two teams of three authors each independently selected studies and extracted data. The primary outcomes were disability-worsening, relapses, occurrence of at least one serious adverse event (AE) and withdrawing from the study or discontinuing the drug because of AEs. Time to conversion to clinically definite MS (CDMS) defined by Poser diagnostic criteria, and probability to discontinue the treatment or dropout for any reason were recorded as secondary outcomes. We synthesized study data using random-effects meta-analyses and performed indirect comparisons between drugs. We calculated odds ratios (OR) and hazard ratios (HR) along with relative 95% confidence intervals (CI) for all outcomes. We estimated the absolute effects only for primary outcomes. We evaluated the credibility of the evidence using the GRADE system.

MAIN RESULTS

We included 10 randomised trials, eight open-label extension studies (OLEs) and four cohort studies published between 2010 and 2016. The overall risk of bias was high and the reporting of AEs was scarce. The quality of the evidence associated with the results ranges from low to very low. Early treatment versus placebo during the first 24 months' follow-upThere was a small, non-significant advantage of early treatment compared with placebo in disability-worsening (6.4% fewer (13.9 fewer to 3 more) participants with disability-worsening with interferon beta-1a (Rebif®) or teriflunomide) and in relapses (10% fewer (20.3 fewer to 2.8 more) participants with relapses with teriflunomide). Early treatment was associated with 1.6% fewer participants with at least one serious AE (3 fewer to 0.2 more). Participants on early treatment were on average 4.6% times (0.3 fewer to 15.4 more) more likely to withdraw from the study due to AEs. This result was mostly driven by studies on interferon beta 1-b, glatiramer acetate and cladribine that were associated with significantly more withdrawals for AEs. Early treatment decreased the hazard of conversion to CDMS (HR 0.53, 95% CI 0.47 to 0.60). Comparing active interventions during the first 24 months' follow-upIndirect comparison of interferon beta-1a (Rebif®) with teriflunomide did not show any difference on reducing disability-worsening (OR 0.84, 95% CI 0.43 to 1.66). We found no differences between the included drugs with respect to the hazard of conversion to CDMS. Interferon beta-1a (Rebif®) and teriflunomide were associated with fewer dropouts because of AEs compared with interferon beta-1b, cladribine and glatiramer acetate (ORs range between 0.03 and 0.29, with substantial uncertainty). Early versus delayed treatmentWe did not find evidence of differences between early and delayed treatments for disability-worsening at a maximum of five years' follow-up (3% fewer participants with early treatment (15 fewer to 11.1 more)). There was important variability across interventions; early treatment with interferon beta-1b considerably reduced the odds of participants with disability-worsening during three and five years' follow-up (OR 0.52, 95% CI 0.32 to 0.84 and OR 0.57, 95% CI 0.36 to 0.89). The early treatment group had 19.6% fewer participants with relapses (26.7 fewer to 12.7 fewer) compared to late treatment at a maximum of five years' follow-up and early treatment decreased the hazard of conversion to CDMS at any follow-up up to 10 years (i.e. over five years' follow-up HR 0.62, 95% CI 0.53 to 0.73). We did not draw any conclusions on long-term serious AEs or discontinuation due to AEs because of inadequacies in the available data both in the included OLEs and cohort studies.

AUTHORS' CONCLUSIONS

Very low-quality evidence suggests a small and uncertain benefit with early treatment compared with placebo in reducing disability-worsening and relapses. The advantage of early treatment compared with delayed on disability-worsening was heterogeneous depending on the actual drug used and based on very low-quality evidence. Low-quality evidence suggests that the chances of relapse are less with early treatment compared with delayed. Early treatment reduced the hazard of conversion to CDMS compared either with placebo, no treatment or delayed treatment, both in short- and long-term follow-up. Low-quality evidence suggests that early treatment is associated with fewer participants with at least one serious AE compared with placebo. Very low-quality evidence suggests that, compared with placebo, early treatment leads to more withdrawals or treatment discontinuation due to AEs. Difference between drugs on short-term benefit and safety was uncertain because few studies and only indirect comparisons were available. Long-term safety of early treatment is uncertain because of inadequately reported or unavailable data.

Teriflunomide for multiple sclerosis

BACKGROUND

This is an update of the Cochrane review "Teriflunomide for multiple sclerosis" (first published in The Cochrane Library 2012, Issue 12).Multiple sclerosis (MS) is a chronic immune-mediated disease of the central nervous system. It is clinically characterized by recurrent relapses or progression, or both, often leading to severe neurological disability and a serious decline in quality of life. Disease-modifying therapies (DMTs) for MS aim to prevent occurrence of relapses and disability progression. Teriflunomide is a pyrimidine synthesis inhibitor approved by both the US Food and Drug Administration (FDA) and the European Medicines Agency (EMA) as a DMT for adults with relapsing-remitting MS (RRMS).

OBJECTIVES

To assess the absolute and comparative effectiveness and safety of teriflunomide as monotherapy or combination therapy versus placebo or other disease-modifying drugs (DMDs) (interferon beta (IFNβ), glatiramer acetate, natalizumab, mitoxantrone, fingolimod, dimethyl fumarate, alemtuzumab) for modifying the disease course in people with MS.

SEARCH METHODS

We searched the Cochrane Multiple Sclerosis and Rare Diseases of the CNS Group Specialised Trials Register (30 September 2015). We checked reference lists of published reviews and retrieved articles and searched reports (2004 to September 2015) from the MS societies in Europe and America. We also communicated with investigators participating in trials of teriflunomide and the pharmaceutical company, Sanofi-Aventis.

SELECTION CRITERIA

We included randomized, controlled, parallel-group clinical trials with a length of follow-up of one year or greater evaluating teriflunomide, as monotherapy or combination therapy, versus placebo or other approved DMDs for people with MS without restrictions regarding dose, administration frequency and duration of treatment.

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures of Cochrane. Two review authors independently assessed trial quality and extracted data. Disagreements were discussed and resolved by consensus among the review authors. We contacted the principal investigators of included studies for additional data or confirmation of data.

MAIN RESULTS

Five studies involving 3231 people evaluated the efficacy and safety of teriflunomide 7 mg and 14 mg, alone or with add-on IFNβ, versus placebo or IFNβ-1a for adults with relapsing forms of MS and an entry Expanded Disability Status Scale score of less than 5.5.Overall, there were obvious clinical heterogeneities due to diversities in study designs or interventions and methodological heterogeneities across studies. All studies had a high risk of detection bias for relapse assessment and a high risk of bias due to conflicts of interest. Among them, three studies additionally had a high risk of attrition bias due to a high dropout rate and two studies had an unclear risk of attrition bias. The studies of combination therapy with IFNβ (650 participants) and the study with IFNβ-1a as controls (324 participants) also had a high risk for performance bias and a lack of power due to the limited sample.Two studies evaluated the benefit and the safety of teriflunomide as monotherapy versus placebo over a period of one year (1169 participants) or two years (1088 participants). A meta-analysis was not conducted. Compared to placebo, administration of teriflunomide at a dose of 7 mg/day or 14 mg/day as monotherapy reduced the number of participants with at least one relapse over one year (risk ratio (RR) 0.72, 95% confidence interval (CI) 0.59 to 0.87, P value = 0.001 with 7 mg/day and RR 0.60, 95% CI 0.48 to 0.75, P value < 0.00001 with 14 mg/day) or two years (RR 0.85, 95% CI 0.74 to 0.98, P value = 0.03 with 7 mg/day and RR 0.80, 95% CI 0.69 to 0.93, P value = 0.004 with 14 days). Only teriflunomide at a dose of 14 mg/day reduced the number of participants with disability progression over one year (RR 0.55, 95% CI 0.36 to 0.84, P value = 0.006) or two years (RR 0.74, 95% CI 0.56 to 0.96, P value = 0.02). When taking the effect of drop-outs into consideration, the likely-case scenario analyses still showed a benefit in reducing the number of participants with at least one relapse, but not for the number of participants with disability progression. Both doses also reduced the annualized relapse rate and the number of gadolinium-enhancing T1-weighted lesions over two years. Quality of evidence for relapse outcomes at one year or at two years was low, while for disability progression at one year or at two years was very low.When compared to IFNβ-1a, teriflunomide at a dose of 14 mg/day had a similar efficacy to IFNβ-1a in reducing the proportion of participants with at least one relapse over one year, while teriflunomide at a dose of 7 mg/day was inferior to IFNβ-1a (RR 1.52, 95% CI 0.87 to 2.67, P value = 0.14; 215 participants with 14 mg/day and RR 2.74, 95% CI 1.66 to 4.53, P value < 0.0001; 213 participants with 7 mg/day). However, the quality of evidence was very low.In terms of safety profile, the most common adverse events associated with teriflunomide were diarrhoea, nausea, hair thinning, elevated alanine aminotransferase, neutropenia and lymphopenia. These adverse events had a dose-related effects and rarely led to treatment discontinuation.

AUTHORS' CONCLUSIONS

There was low-quality evidence to support that teriflunomide at a dose of 7 mg/day or 14 mg/day as monotherapy reduces both the number of participants with at least one relapse and the annualized relapse rate over one year or two years of treatment in comparison with placebo. Only teriflunomide at a dose of 14 mg/day reduced the number of participants with disability progression and delayed the progression of disability over one year or two years, but the quality of the evidence was very low. The quality of available data was too low to evaluate the benefit teriflunomide as monotherapy versus IFNβ-1a or as combination therapy with IFNβ. The common adverse effects were diarrhoea, nausea, hair thinning, elevated alanine aminotransferase, neutropenia and lymphopenia. These adverse effects were mostly mild-to-moderate in severity, but had a dose-related effect. New studies of high quality and longer follow-up are needed to evaluate the comparative benefit of teriflunomide on these outcomes and the safety in comparison with other DMTs.

Teriflunomide: a once-daily oral medication for the treatment of relapsing forms of multiple sclerosis

PURPOSE

The purpose was to summarize US prescribing information for teriflunomide in the treatment of patients with relapsing forms of multiple sclerosis (RMS), with reference to clinical efficacy and safety outcomes.

METHODS

In September 2012, the US Food and Drug Administration granted approval for the use of teriflunomide, 14 mg and 7 mg once daily, to treat RMS on the basis of the results of a Phase II study and the Phase III TEMSO (Teriflunomide Multiple Sclerosis Oral) trial. After recent updates to the prescribing information (October 2014), key findings from these and 2 other Phase III clinical trials, TOWER (Teriflunomide Oral in People With Relapsing Multiple Sclerosis) and TOPIC (Oral Teriflunomide for Patients with a First Clinical Episode Suggestive of Multiple Sclerosis), and practical considerations for physicians are summarized.

FINDINGS

Teriflunomide, 14 mg and 7 mg, significantly reduced mean number of unique active lesions on magnetic resonance imaging (MRI; P < 0.05 for both doses) in the Phase II study. In the TEMSO and TOWER studies, the 14-mg dose of teriflunomide significantly reduced annualized relapse rate (31% and 36% relative risk reduction compared with placebo, respectively; both P < 0.001) and risk of disability progression sustained for 12 weeks (hazard ratio vs placebo 0.70 and 0.69, respectively; both P < 0.05). The 7-mg dose significantly (P < 0.02) reduced annualized relapse rate in both studies, although the reduction in risk of disability progression was not statistically significant. Teriflunomide treatment was also associated with significant efficacy on MRI measures of disease activity in TEMSO; both doses significantly reduced total lesion volume and number of gadolinium-enhancing T1 lesions. TOPIC evaluated patients with a first clinical event consistent with acute demyelination and brain MRI lesions characteristic of multiple sclerosis. More patients were free of relapse in the teriflunomide 14-mg and 7-mg groups than in the placebo group (P < 0.05 for both comparisons). In safety data pooled from the 4 studies, adverse events occurring in ≥2% of patients and ≥2% higher than in the placebo group were headache, alanine aminotransferase increase, diarrhea, alopecia (hair thinning), nausea, paresthesia, arthralgia, neutropenia, and hypertension. Routine monitoring procedures before and on treatment are recommended to assess potential safety issues. Women of childbearing potential must use effective contraception and, in the event of pregnancy, undergo an accelerated elimination procedure to reduce plasma concentrations of teriflunomide.

IMPLICATIONS

Clinical evidence suggests that teriflunomide is an effective therapeutic choice for patients with RMS, both as an initial treatment and as an alternative for patients who may have experienced intolerance or inadequate response to a previous or current disease-modifying therapy.

▼Teriflunomide for multiple sclerosis

▼Teriflunomide (Aubagio-Genzyme Therapeutics), the main metabolite of the disease-modifying anti-rheumatic drug leflunomide,1 is an immunomodulatory agent with anti-inflammatory properties.2 It is a new oral treatment licensed for adults with relapsing-remitting multiple sclerosis. Here we discuss the evidence for its effectiveness and safety, and consider its place in therapy.

[TERIFLUNOMIDE: A NEW ORAL IMMUNOMODULATING AGENT FOR MULTIPLE SCLEROSIS]

Multiple sclerosis (MS) is the autoimmune, demyelinating, neurodegenerative disorder of the central nervous system (CNS). There are nine drugs available in Hungary reimbursed by the National Health Insurance Fund of Hungary (OEP) to reduce the activity of the disease, from which seven can be used as first line therapies. We have approximately 20 years of experience with the interferon beta-1a/1b and glatiramer-acetate products. Though in case of approximately 30% of the patients using one of the first line drugs, the disease remains active, that we call break-through disease. The reasons for breakthrough disease could be the insufficient adherence and compliance, the appearance of neutralizing antibodies or the high activity of the disease. One of the oral immunomodulating drugs for MS, teriflunomide, was registered in Europe in 2013. Because of the anti-proliferative and anti-inflammatory effect of teriflunomide, it can be used for the reduction of the disease activity in the relapsing-remitting course of MS. The effect of teriflunomide was proved in one Phase II. and four Phase III. (TEMSO, TOWER, TENERE, TOPIC) studies. Teriflunomide 14 mg once daily was able to demonstrate in two consecutive placebo-controlled phase 3 clinical trials that significantly reduces the relapse rate (31.5% and 36.3%) and in both studies significantly reduces the sustained disability progression (29.8% and 31.5%) moreover delays the appearance of the clinically definitive MS in patients with clinically isolated syndrome (CIS). According to the TENERE study there were no significant differences observed between teriflunomide 14 mg and IFNβ-α a s.c. in time to failure and annualized relapse rate but the treatment satisfaction domains of global satisfaction, side-effects and convenience were significantly improved with teriflunomide compared with s.c. IFNβ-α.

Teriflunomide (AUBAGIO). Multiple sclerosis: just a metabolite of leflunomide

In mid-2014, subcutaneous or intramuscular interferon beta injection is the standard disease-modifying treatment for patients with relapsing-remitting multiple sclerosis, in the absence of a better alternative. Teriflunomide, the main active metabolite of leflunomide, has been approved as an oral treatment in this setting. Both substances have immunosuppressive effects. Clinical evaluation of teriflunomide is based on a comparative trial versus interferon beta-1a in 324 patients and on two placebo-controlled trials in a total of about 2300 patients lasting 1 to 2 years. In these trials, oral teriflunomide at a dose of 14 mg per day led to a statistically significant decrease in the average annual number of relapses compared to placebo, but teriflunomide may be less effective than interferon beta. No impact on the progression of disability has been shown during less than 2 years of follow-up. The burdensome adverse effect profile of teriflunomide is similar to that of leflunomide and includes hepatotoxicity, infections, leukopenia, arterial hypertension, peripheral neuropathy and alopecia. The long half-life of teriflunomide (about 19 days) complicates the management of its adverse effects and multiple drug interactions, and has important implications for patients wishing to have children. Teriflunomide is teratogenic in animals and should not be used by pregnant women. Fetal toxicity via semen cannot be ruled out. In practice, the adverse effects of teriflunomide in multiple sclerosis are disproportionate to its efficacy. It is better to choose interferon beta, despite its limitations.

Coronary artery disease and cancer mortality in a cohort of workers exposed to vinyl chloride, carbon disulfide, rotating shift work, and o-toluidine at a chemical manufacturing plant

BACKGROUND

We updated through 2007 the mortality experience of 1,874 workers employed at a New York State chemical manufacturing plant between 1946 and 2006.

METHODS

Reassessed exposures to vinyl chloride, carbon disulfide, and shift work and categories of o-toluidine exposure were based on year, department and job title. Standardized mortality ratios (SMR) compared mortality to that of the US population. Internal comparisons used directly standardized rate ratios.

RESULTS

Hepatobiliary cancer mortality was elevated among workers ever exposed to vinyl chloride (SMR = 3.80, 95% confidence interval 1.89-6.80); directly standardized rates increased with increasing vinyl chloride exposure duration. No increase in non-Hodgkin lymphoma mortality was observed with vinyl chloride and shift work exposures. Internal comparisons showed increased coronary artery disease mortality among long-term workers exposed to carbon disulfide and shift work for 4 years or more.

CONCLUSIONS

Excess coronary artery disease mortality confirms earlier results; further investigation is needed to understand risk factors.

Bladder cancer incidence among workers exposed to o-toluidine, aniline and nitrobenzene at a rubber chemical manufacturing plant

BACKGROUND

An earlier investigation found increased bladder cancer incidence among workers at a rubber chemical manufacturing plant that used o-toluidine, aniline and nitrobenzene. The cohort was expanded to include additional workers (n=1875) and updated through 2007 to assess bladder cancer with improved exposure characterisation.

METHODS

Work histories were updated and exposure categories and ranks were developed for o-toluidine, aniline and nitrobenzene combined. Incident cancers were identified by linkage to six state cancer registries. Residency in time-dependent cancer registry catchment areas was determined. SIR and standardised rate ratios for bladder cancer were calculated by exposure category and cumulative rank quartiles for different lag periods. Cox regression was used to model bladder cancer incidence with estimated cumulative rank, adjusting for confounders. Indirect methods were used to control for smoking.

RESULTS

Excess bladder cancer was observed compared to the New York State population (SIR=2.87, 95% CI 2.02 to 3.96), with higher elevations among workers definitely exposed (moderate/high) (SIR=3.90, 95% CI 2.57 to 5.68), and in the highest cumulative rank quartile (SIR=6.13, 95% CI 2.80 to 11.6, 10-year lag). Bladder cancer rates increased significantly with estimated cumulative rank (10-year lag). Smoking only accounted for an estimated 8% elevation in bladder cancer incidence.

CONCLUSIONS

Bladder cancer incidence remains elevated in this cohort and significantly associated with estimated cumulative exposure. Results are consistent with earlier findings in this and other cohorts. Despite other concurrent chemical exposures, we consider o-toluidine most likely responsible for the bladder cancer incidence elevation and recommend a re-examination of occupational exposure limits.

Teriflunomide for multiple sclerosis

BACKGROUND

Disease-modifying therapies (DMTs) for multiple sclerosis aim to specifically reduce inflammation in relapsing multiple sclerosis and promote neuroprotection and neurorepair in progressive multiple sclerosis (MS). Most of the currently available disease-modifying drugs (DMDs) require regular and frequent parenteral administration, which imposes a burden on patients and leads to reduced adherence. Not all MS patients respond adequately to current DMDs and, therefore, alternative MS treatments with less invasive routes of administration and new modes of action are required to expand the current treatment repertoire, increase adherence, and thereby improve efficacy. As one of the oral DMDs, teriflunomide is a potentially promising new oral agent in the treatment of relapsing MS. It inhibits dihydro-orotate dehydrogenase (DHODH) and the synthesis of pyrimidine and has selective immunosuppressive and immunomodulatory properties.

OBJECTIVES

To explore the potential benefits of teriflunomide and so expand the available DMT options, the effectiveness and safety of teriflunomide, as monotherapy or combination therapy, were assessed versus placebo or approved DMDs (IFN-β, glatiramer acetate, natalizumab, mitoxantrone, fingolimod) for modifying disease in patients with MS.

SEARCH METHODS

The Trials Search Co-ordinator searched the Cochrane Multiple Sclerosis and Rare Diseases of the Central Nervous System Group Specialised Register (27 June 2012). We checked references in identified trials and manually searched the reports (2004 to June 2012) from neurological associations and MS societies. We also communicated with researchers participating in trials on teriflunomide and contacted Sanofi-Aventis.

SELECTION CRITERIA

All randomised, double-blind, controlled, parallel clinical trials (RCTs) with a length of follow-up of at least one year evaluating teriflunomide, as monotherapy or combination therapy, versus placebo or other treatments (IFN-β, glatiramer acetate, natalizumab, mitoxantrone, fingolimod) for patients with MS. Titles and abstracts of the citations retrieved by the literature search were screened independently for inclusion or exclusion by two review authors. Any disagreement regarding inclusion was resolved by discussion or by referral to a third assessor if necessary.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed trial quality. Disagreements were discussed and resolved by consensus among review authors. Principal investigators of included studies were contacted for additional data or confirmation of information.

MAIN RESULTS

Two studies involving 1204 people evaluated the efficacy and safety of teriflunomide 7 mg and 14 mg, alone or with add-on IFN-β, versus placebo for adult patients with relapsing forms of MS (relapsing-remitting (RRMS), secondary progressive (SPMS) with relapse, and progressive relapsing MS (PRMS)) and an entry Expanded Disability Status Scale (EDSS) score of ≤ 5.5. Both studies had high attrition bias (26.8% and 36.4% attrition respectively). Teriflunomide 7 or 14 mg alone had potential benefits on reducing relapse rates, and alone or with add-on IFN-β was safe for patients with relapsing forms of MS in the short term. The most common adverse events included nasopharyngitis, headache, diarrhoea, fatigue, elevated alanine aminotransferase levels, nausea, hair thinning or decreased hair density, influenza, back pain, urinary tract infection, and pain in the arms or legs. Four ongoing trials were identified.

AUTHORS' CONCLUSIONS

We found low-level evidence for the use of teriflunomide as a disease-modifying therapy for MS, due to the limited quality of the available RCTs. We did not conduct meta-analysis because of the clinical and methodological diversity of the included studies. Short-term teriflunomide, 7 or 14 mg alone or with add-on IFN-β, was safe for patients with relapsing MS. Both teriflunomide 7 and 14 mg alone had potential benefits for patients with relapsing forms of MS. We are waiting for the publication of ongoing trials. RCTs with high methodological quality and longer periods of observation are needed to assess safety, disability progression, neuroprotection and quality of life.

An update on the therapy of canine demodicosis

Canine demodicosis, a disease caused by a proliferation of Demodex mites, typically leads to alopecia, comedones, follicular papules and pustules, scaling, and crusting. It may be treated with either amitraz rinses or macrocyclic lactones. Amitraz rinse is approved for application every 2 weeks at a concentration of 0.025%. Higher concentrations and more frequent applications increase the success rate but also increase the risk for adverse effects. Ivermectin is used at 0.3 to 0.6 mg/kg/d PO and moxidectin at 0.2 to 0.5 mg/kg/d PO. Both drugs may cause adverse neurologic effects in sensitive dogs. Milbemycin oxime at 1 to 2 mg/kg/d PO is a safer treatment option. A weekly spot-on combination of 2.5% moxidectin and 10% imidacloprid is recommended for milder forms of the disease.

Randomized trial of oral teriflunomide for relapsing multiple sclerosis

BACKGROUND

Teriflunomide is a new oral disease-modifying therapy for relapsing forms of multiple sclerosis.

METHODS

We concluded a randomized trial involving 1088 patients with multiple sclerosis, 18 to 55 years of age, with a score of 0 to 5.5 on the Expanded Disability Status Scale and at least one relapse in the previous year or at least two relapses in the previous 2 years. Patients were randomly assigned (in a 1:1:1 ratio) to placebo, 7 mg of teriflunomide, or 14 mg of teriflunomide once daily for 108 weeks. The primary end point was the annualized relapse rate, and the key secondary end point was confirmed progression of disability for at least 12 weeks.

RESULTS

Teriflunomide reduced the annualized relapse rate (0.54 for placebo vs. 0.37 for teriflunomide at either 7 or 14 mg), with relative risk reductions of 31.2% and 31.5%, respectively (P<0.001 for both comparisons with placebo). The proportion of patients with confirmed disability progression was 27.3% with placebo, 21.7% with teriflunomide at 7 mg (P=0.08), and 20.2% with teriflunomide at 14 mg (P=0.03). Both teriflunomide doses were superior to placebo on a range of end points measured by magnetic resonance imaging (MRI). Diarrhea, nausea, and hair thinning were more common with teriflunomide than with placebo. The incidence of elevated alanine aminotransferase levels (≥1 times the upper limit of the normal range) was higher with teriflunomide at 7 mg and 14 mg (54.0% and 57.3%, respectively) than with placebo (35.9%); the incidence of levels that were at least 3 times the upper limit of the normal range was similar in the lower- and higher-dose teriflunomide groups and the placebo group (6.3%, 6.7%, and 6.7%, respectively). Serious infections were reported in 1.6%, 2.5%, and 2.2% of patients in the three groups, respectively. No deaths occurred.

CONCLUSIONS

Teriflunomide significantly reduced relapse rates, disability progression (at the higher dose), and MRI evidence of disease activity, as compared with placebo. (Funded by Sanofi-Aventis; TEMSO ClinicalTrials.gov number, NCT00134563.).

Evaluation of the potential for interaction between a metaflumizone-amitraz combination and dexmedetomidine hydrochloride in dogs

This study investigated the effects on cardiovascular parameters, if any, of a commercially available combination of metaflumizone and amitraz administered to healthy, telemetered beagles that were subsequently sedated with dexmedetomidine. Dogs were sedated first without any pretreatment and then after pretreatment with metaflumizone and amitraz. Baseline values of all parameters were within normal limits for all dogs before the first anesthetic event. At 10 and 20 minutes after onset of sedation, oxygen saturation as measured by pulse oximetry was significantly higher for dogs that were pretreated with metaflumizone and amitraz. At all times after induction of sedation, blood pressure, heart rate, and baseline body temperature for dogs pretreated with metaflumizone and amitraz were not statistically different from when they were not pretreated. In conclusion, prior treatment with metaflumizone and amitraz did not influence the hemodynamic response to dexmedetomidine in telemetered dogs.

Cholestatic jaundice and IgA nephropathy induced by OTC muscle building agent superdrol

Over the counter (OTC) medicines are commonly used in the United States despite a lack of scientific evidence for clinical utility and toxicity associated with their use. A case of jaundice and IgA nephropathy as a consequence of use of a muscle enhancing OTC supplement that was advertised as innocuous with no hormonal activity is described. IgA nephropathy has not been described previously in association with the use of testosterone. The case highlights that, besides adulteration, the misrepresentation of chemicals present in OTC medications and supplements can create confusion and a false sense of security with their use.

Suspected drug-induced destructive cholangitis in a young dog

A nine-month-old miniature doberman was referred for the evaluation of chronic icterus. History and clinical and histopathological findings were supportive of a diagnosis of drug-induced destructive cholangitis. The main histopathological findings were canalicular, centrilobular cholestasis and ductopenia with moderate inflammatory infiltrate. The dog had received three types of treatment for demodicosis before the onset of jaundice. Amoxicillin-clavulanate, amitraz, milbemycin oxime or an interaction between two of the three drugs may have been responsible for the destructive cholangitis.

Multimodal approach to treatment for control of fur mites

Ectoparasites pose numerous research, health, and management problems for researchers and institutions. Our facility management experience was complicated by recurrence of murine fur mite (Radfordia affinis) infestation after several rounds of single-mode fur mite treatment with dichlorvos in the cage bedding. Subsequently, we successfully eradicated the fur mites using a multidrug therapeutic protocol. Over an 8-wk treatment period, 2 applications of topical selamectin were administered in conjunction with amitraz- and fipronil-treated nestlets changed weekly. Mice tolerated the therapy well with no side effects noted, and to date there has been no recrudescence. To our knowledge, this report is the first to describe combined use of these specific therapeutic agents to control fur mite infestation in laboratory mice.

Applicator exposure to acetochlor based on biomonitoring

Biomonitoring was used to assess the combined dermal, oral, and inhalation exposure associated with the agricultural use of Harness Plus, an emulsifiable concentrate formulation of the herbicide acetochlor. Twenty Spanish farmers handled and applied acetochlor to maize in the spring of 2003, following the product label recommendations. Open- and closed-cabin applications were equally represented. Urine was collected during six consecutive days, starting the day prior to application. Daily composites were analyzed for 2-ethyl-6-methyl-aniline, a common chemophore representing the major urinary acetochlor metabolites. All applicators showed detectable concentrations in urine after application. Although, the open-cabin applicators treated fewer hectares, they showed significantly higher exposure compared to the closed-cabin applicators (average exposure: 0.004 and 0.002 mg/kg bw/day, respectively). Linear regression analysis suggested that untracked incidents had a significant impact on the total exposure. Other events that may have contributed to the observed exposure are repair of faulty equipment, accidental spillages, splashes, and inadequate use of protective gloves. The average margins of exposure (MOE) for farmers ranged from 23,000 (open cabin) to about 44,000 (closed cabin). For professional applicators the MOEs were 10-fold lower. These MOEs clearly indicate that no adverse health effects should be expected from agricultural acetochlor applications.

[Effects of acetochlor and methamidophos on culturable fungal population and community structure in black soil]

By the methods of CFU and rDNA-PCR-DGGE, this paper studied the dynamic changes of culturable fungal populations, community structure, and population richness in black soil under stress of acetochlor and methamidophos. The results showed that the growth of fungi was promoted under lower concentration acetochlor (50 mg x kg(-1)), but long-standing inhibited under its higher concentration (250 mg x kg(-1)). 250 mg kg(-1) methamidophos promoted the growth of culturable fungi intensively during 8-week period, resulting in 10 times increase in CFU of fungi than the control, while low concentration methamidophos (50 mg x kg(-1)) had no evident effect. The richness of culturable fungi in soil treated by medium and high concentration acetochlor was decreased irreversibly. Cluster analysis of fungal rDNA-PCR-DGGE fingerprints profile showed that acetochlor and methamidophos could change the culturable fungal community structure diversely, and the effect of methomidophos was more obvious.

[Amitraz intoxications in the horse: cases and backgrounds]

Since the only registrated anti-ectoparasiticum for horses (foxim) is no longer available in The Netherlands, some cases of amitraz intoxication of the horse have occurred. In this article the literature concerning amitraz intoxications and experiments will be discussed and some cases will be described.

Continued Epidemic of Bladder Cancer in Workers Exposed to Ortho-Toluidine in a Chemical Factory

Ortho-toluidine (o-toluidine), an aromatic amine, is classified by the International Agency for Research on Cancer as a probable human carcinogen. A cohort study published in 1991 reported a 6.5-fold excess incidence of bladder cancer in a chemical plant that used o-toluidine. We report 19 additional cases of bladder cancer among workers in this cohort, yielding a total of 34 cases of bladder cancer in the cohort to date. The number of bladder cancers diagnosed in the recent period has increased. The timing of onset of exposure to o-toluidine of numerous cases of bladder cancer after 1968, and especially 1975, suggests that potentially confounding occupational exposures other than o-toluidine were not responsible for the observed excess bladder cancer. A formal cohort update is strongly indicated. This study further supports the human bladder carcinogenicity of o-toluidine.

Exposure to the herbicide acetochlor alters thyroid hormone-dependent gene expression and metamorphosis in Xenopus Laevis

A growing number of substances released into the environment disrupt normal endocrine mechanisms in a wide range of vertebrates. Little is known about the effects and identities of endocrine-disrupting chemicals (EDCs) that target thyroid hormone (TH) action, particularly at the cellular level. Frog tadpole metamorphosis depends completely on TH, which has led to the suggestion of a metamorphosis-based assay for screening potential EDCs. A major mechanism of TH action is the alteration of gene expression via hormone-bound nuclear receptors. To assess the gene expression profiles in the frog model, we designed a novel multispecies frog cDNA microarray. Recently, the preemergent herbicide acetochlor was shown to accelerate 3,5,3 -triiodothyronine (T3)-induced forelimb emergence and increase mRNA expression of thyroid hormone ss receptors in ranid tadpoles. Here we show that T3-induced metamorphosis of Xenopus laevis, a species commonly used in the laboratory, is accelerated upon acute exposure to an environmentally relevant level of acetochlor. The morphologic changes observed are preceded by alterations in gene expression profiles detected in the tadpole tail, and the nature of these profiles suggest a novel mechanism of action for acetochlor.

Liver dysfunction among workers handling 5-nitro-o-toluidine

BACKGROUND

5-Nitro-o-toluidine is an aromatic nitro amino compound. While other aromatic compounds are known to damage the human liver and are registered as toxic substances, toxicity information concerning 5-nitro-o-toluidine is lacking.

AIMS

To investigate the hepatotoxicity of 5-nitro-o-toluidine.

PATIENTS AND METHODS

Of 15 workers in the same factory who handled 5-nitro-o-toluidine, three were hospitalised with symptoms of acute liver dysfunction. Suspecting a link between liver dysfunction and working conditions, we correlated workplace factors with clinical findings in all 15 workers.

RESULTS

Blood biochemistry tests indicated liver damage in seven of 15 study subjects. Workers who handled 5-nitro-o-toluidine and nitrosyl sulphuric acid often loosened their respiratory protective equipment shortly after 5-nitro-o-toluidine powder had been dispersed into the air of the room. No potential hepatotoxins were present except for 5-nitro-o-toluidine. Six of the affected workers had handled 5-nitro-o-toluidine 12 to 20 times; the seventh worker had handled the powder three times; and the other eight workers without liver dysfunction had handled the material once or twice. No other significant differences in background were evident between the affected and unaffected workers, such as age, sex, or protective measures. Histological findings during recovery from liver damage were similar to those of acute viral hepatitis. None of the 15 subjects has demonstrated liver damage since the factory was closed.

CONCLUSIONS

A link between liver dysfunction and 5-nitro-o-toluidine exposure is suggested by greater severity of liver dysfunction associated with more episodes of handling.

A further cohort study of workers employed at a factory manufacturing chemicals for the rubber industry, with special reference to the chemicals 2-mercaptobenzothiazole (MBT), aniline, phenyl-beta-naphthylamine and o-toluidine

OBJECTIVES

To investigate mortality and cancer morbidity in workers from a factory manufacturing chemicals for the rubber industry.

METHODS

The mortality (1955-96) and cancer morbidity experience (1971-92) of a cohort of 2160 male production workers from a chemical factory in north Wales were investigated. All subjects had at least 6 months employment at the factory and some employment in the period 1955-84. Detailed job histories were abstracted from company computerised records and estimates of individual cumulative exposure to 2-mercaptobenzothiazole (MBT) and its derivatives were obtained, with a job exposure matrix derived by a former factory hygienist. Durations of employment in the aniline, phenyl-beta-naphthylamine (PBN) and o-toluidine departments were also calculated. Two analytical approaches were used, indirect standardisation and Poisson regression.

RESULTS

Based on serial rates for the general population of England and Wales, observed mortality for the total cohort was close to expectation for all causes (observed (obs) deaths 1131, expected (exp) deaths 1114.5, standardised mortality ratio (SMR) 101), and for all cancers (obs 305, exp 300.2, SMR 102). There was a significant (p < 0.05) excess mortality from cancer of the bladder in the 605 study subjects potentially exposed to one or more of the four chemicals being investigated (obs 9, exp 3.25, SMR 277, 95% confidence interval (95% CI) 127 to 526). This excess was dependent primarily on deaths occurring > 20 years after first exposure in those who started employment before 1955 (obs 7, exp 1.25, SMR 560, 95% CI 225 to 1154, p < 0.001). There were 30 subjects in the total study cohort who, on the basis of death certificates or cancer registration particulars, had had malignant bladder cancer. In separate analyses of the four exposure history variables (after adjustment for age), Poisson regression showed significant positive trends for risk of notification of bladder cancer increasing with cumulative duration of employment in the PBN (p < 0.001) and o-toluidine departments (p < 0.01); similar findings were not obtained for cumulative exposure to MBT or for duration of employment in the aniline department. In a simultaneous analysis of all four chemical exposure variables, a significant positive trend remained for duration of employment with exposure to PBN (p < 0.05). Further analyses of all cases of bladder cancer (malignant and benign diagnoses) used employment histories lagged by 15 years; similar findings were obtained.

CONCLUSIONS

It seems likely that some members of this cohort have had occupational bladder cancer. Confident interpretation is difficult because of small numbers in the exposed subcohorts, relatively crude measures of exposure assessment for the four chemicals under study, and presence of unconsidered potential chemical confounders. The simplest interpretation of the findings about bladder cancer may be that PBN (or a chemical reagent or chemical intermediate associated with its production at this factory in the 1930s and 1940s) is a bladder carcinogen. Priority should be given, however, to obtaining information on the cancer experience of other working populations exposed to PBN or to o-toluidine.