Objectives:To evaluate the efficacy and safety of 18 months of tafamidis treatment in patients with early-stage V30M transthyretin familial amyloid polyneuropathy (TTR-FAP). Methods:In this randomized, double-blind trial, patients received tafamidis 20 mg QD or placebo.Coprimary endpoints were the Neuropathy Impairment Score-Lower Limbs (NIS-LL) responder analysis (Ͻ2-point worsening) and treatment-group difference in the mean change from baseline in Norfolk Quality of Life-Diabetic Neuropathy total score (TQOL) in the intent-to-treat (ITT) population (n ϭ 125). These endpoints were also evaluated in the efficacy-evaluable (EE; n ϭ 87) population. Secondary endpoints, including changes in neurologic function, nutritional status, and TTR stabilization, were analyzed in the ITT population.Results: There was a higher-than-anticipated liver transplantation dropout rate. No differences were observed between the tafamidis and placebo groups for the coprimary endpoints, NIS-LL responder analysis (45.3% vs 29.5% responders; p ϭ 0.068) and change in TQOL (2.0 vs 7.2; p ϭ 0.116) in the ITT population. In the EE population, significantly more tafamidis patients than placebo patients were NIS-LL responders (60.0% vs 38.1%; p ϭ 0.041), and tafamidis patients had better-preserved TQOL (0.1 vs 8.9; p ϭ 0.045). Significant differences in most secondary endpoints favored tafamidis. TTR was stabilized in 98% of tafamidis and 0% of placebo patients (p Ͻ 0.0001). Adverse events were similar between groups. Conclusions:Although the coprimary endpoints were not met in the ITT population, tafamidis was associated with no trend toward more NIS-LL responders and a significant reduction in worsening of most neurologic variables, supporting the hypothesis that preventing TTR dissociation can delay peripheral neurologic impairment. Classification of evidence:This study provides Class II evidence that 20 mg tafamidis QD was associated with no difference in clinical progression in patients with TTR-FAP, as measured by the NIS-LL and the Norfolk QOL-DN score. Secondary outcomes demonstrated a significant delay in peripheral neurologic impairment with tafamidis, which was well tolerated over 18 months. Neurology® 2012;79:785-792 GLOSSARY AE ϭ adverse event; ANCOVA ϭ analysis of covariance; ARR ϭ absolute risk reduction; CI ϭ confidence interval; DPN ϭ diabetic polyneuropathy; EE ϭ efficacy-evaluable; ITT ϭ intent-to-treat; LS Mean ϭ least-squares mean; mBMI ϭ modified body mass index; NIS-LL ϭ Neuropathy Impairment Score-Lower Limbs; NNT ϭ number needed to treat; QOL ϭ quality of life; QOL-DN ϭ Quality of Life-Diabetic Neuropathy Questionnaire; TQOL ϭ total quality of life; TTR-FAP ϭ transthyretin familial amyloid polyneuropathy.
ALN-TTR01 and ALN-TTR02 suppressed the production of both mutant and nonmutant forms of transthyretin, establishing proof of concept for RNAi therapy targeting messenger RNA transcribed from a disease-causing gene. (Funded by Alnylam Pharmaceuticals; ClinicalTrials.gov numbers, NCT01148953 and NCT01559077.).
We describe a kindred with slowly progressive gastrointestinal symptoms and autonomic neuropathy caused by autosomal dominant, hereditary systemic amyloidosis. The amyloid consists of Asp76Asn variant β(2)-microglobulin. Unlike patients with dialysis-related amyloidosis caused by sustained high plasma concentrations of wild-type β(2)-microglobulin, the affected members of this kindred had normal renal function and normal circulating β(2)-microglobulin values. The Asp76Asn β(2)-microglobulin variant was thermodynamically unstable and remarkably fibrillogenic in vitro under physiological conditions. Previous studies of β(2)-microglobulin aggregation have not shown such amyloidogenicity for single-residue substitutions. Comprehensive biophysical characterization of the β(2)-microglobulin variant, including its 1.40-Å, three-dimensional structure, should allow further elucidation of fibrillogenesis and protein misfolding.
ObjectiveTo compare the natural history of familial transthyretin amyloid polyneuropathies (FAP) due to the Val30Met, Ser77Tyr, and Ile107Val mutations in France with the classical Portuguese Val30Met FAP.MethodsWe compared 84 French patients with a control group of 110 Portuguese patients carrying the Val30Met mutation also living in France, all referred to and followed at the French National FAP Reference Center from 1988 to 2010. Clinical examination, functional and walking disability scores, nerve conduction studies, and muscle biopsies are reported. We also conducted a comprehensive literature review to further determine the range of phenotypic expression.ResultsBy comparison with Portuguese Val30Met FAP, French Ile107Val, Ser77Tyr, and LateVal30Met FAP showed more rapid and severe disease progression; onset of gait disorders was 3 times more rapid (p < 0.0001) and the rate of modified Norris test decline was up to 40 times faster in Ile107Val patients (p < 0.0001). Median survival was much shorter in Ile107Val and in Val30Met mutation with late onset (>50 years; LateMet30) FAP (p = 0.0005). Other distinctive features relative to the Portuguese patients included atypical clinical presentations, demyelination on nerve conduction studies (p = 0.0005), and difficult identification of amyloid deposits in nerve and muscle biopsies.InterpretationIle107Val and LateMet30 mutations are associated with the most debilitating and severe FAP ever described, with rapid onset of tetraparesis and shorter median survival. It could be explained by frequent large‐fiber involvement and associated demyelination and more severe axonal loss. These findings have major implications for genetic counseling and patient management as new therapeutic options are being assessed in clinical trials (TTR gene silencing). Ann Neurol 2015;78:901–916
To report the long-term follow-up (mean, 41 months; range, 25-55 months) of patients with demyelinating neuropathy occurring after tumor necrosis factor-␣ (TNF-␣) blocker treatment (infliximab [Remicade], etanercept [Enbrel], and adalimumab [Humira]).Background: Demyelinating neuropathy is a rare adverse event of anti-TNF-␣ therapy. Improvement usually occurs after drug interruption and/or in association with usual treatments for demyelinating neuropathies.Design: Case report with review of the previously published cases.Setting: University hospital in Le Kremlin-Bicê tre, France: tertiary reference center for peripheral neuropathies and national reference center for rare peripheral neuropathies (www.nnerf.fr).Patients: Five patients (4 men, mean age, 47 years) who developed a demyelinating neuropathy during anti-TNF-␣ therapy.Main Outcome Measure: Development of neuropathy.Results: Neuropathy developed early (8 months) after treatment introduction. Various clinical patterns were encountered, including pure sensory neuropathy. Immunomodulating treatments were always required for neuropathy control. Chronic demyelinating neuropathy developed either after change of anti-TNF-␣ drug or spontaneously after treatment discontinuation without any drug reintroduction. Conclusion:Influence of anti-TNF-␣ treatment continuation on the long-term course of neuropathy is variable, suggesting that anti-TNF-␣ treatment withdrawal is not always necessary for neuropathy control.
There is better recognition of amyloid neuropathies, and hope for enrolling patients with FAP in future clinical trials testing new antiamyloid drugs.
In most patients with advanced Met30 TTR-FAP, Tafamidis is not able to stop disease progression, in respect of both NIS-LL and disability. Other anti-amyloid medicines should be assessed in this context.
Familial amyloidosis with polyneuropathy (FAP) in France have a large genetic heterogeneity with 29 transthyretin (TTR) gene mutations; Met30-TTR is the most frequent one (62%); followed by Tyr77-TTR (11.8%) and Phe77-TTR (6.2%). Analysis of 60 FAP patients diagnosed during the period 2008-2010 showed amyloid polyneuropathy was initially suspected in only 38% patients. TTR Met30 of Portuguese ancestry is different from TTR Met30 of non Portuguese ancestry and other non Met30 variants in geographical distribution and clinical presentation. There are three additional phenotypes of the neuropathy including multifocal upper limbs neuropathy, ataxic polyneuropathy and motor neuropathy. Patients with Tyr77-TTR are characterized by a late onset (>50 years), frequent ataxic phenotype; they are localized mainly in north of France. The more frequent use of the TTR genetic tests and the French network for FAP will help in the future to improve diagnosis and care.
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