http://informahealthcare.com/amy ISSN: 1350-6129 (print), 1744-2818 (electronic) Amyloid, 2015; 22(2): 79–83 ! 2014 Informa UK Ltd. DOI: 10.3109/13506129.2014.997872
ORIGINAL ARTICLE
Safety and efficacy of long-term diflunisal administration in hereditary transthyretin (ATTR) amyloidosis Yoshiki Sekijima1,2, Kana Tojo1, Hiroshi Morita1, Jun Koyama3, and Shu-ichi Ikeda1,2 Department of Medicine (Neurology and Rheumatology), Shinshu University School of Medicine, Matsumoto, Japan, 2Institute for Biomedical Sciences, Shinshu University, Matsumoto, Japan, and 3Department of Cardiovascular Medicine, Shinshu University School of Medicine, Matsumoto, Japan
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1
Abstract
Keywords
Background: A recent 2-year randomized controlled trial indicated that the transthyretin (TTR) tetramer stabilizer, diflunisal, inhibits polyneuropathy progression and preserves quality of life in hereditary ATTR amyloidosis. However, its long-term outcomes are unknown. Here, we report tolerance and efficacy of long-term diflunisal administration in hereditary ATTR amyloidosis. Methods: Diflunisal was administered orally at 500 mg/day to 40 Japanese hereditary ATTR amyloidosis patents who were not candidates for liver transplantation. The observation period ranged from 2 to 116 months (mean ± SD: 38.0 ± 31.2 months). Results: Diflunisal-related adverse events included deterioration of renal function and thrombocytopenia resulting in discontinuation of the drug in three patients. Orally administered diflunisal significantly increased serum TTR concentration (p ¼ 0.001) and stabilized TTR tetramer structure in each patient. Longitudinal analyses of data collected at baseline, 24 months, and after 24 months confirmed sustaining effects of diflunisal on both neurological and cardiac functions. Notably, ulnar compound muscle action potential amplitude, cardiac wall thickness, and ejection fraction were not deteriorated after 24 months of treatment. Conclusions: Diflunisal was tolerated well by most hereditary ATTR amyloidosis patients, although renal function and blood cell counts must be carefully monitored. Clinical effects of diflunisal were sustained after 2 years of treatment.
Amyloid, clinical trial, diflunisal, familial amyloid polyneuropathy, hereditary ATTR amyloidosis, transthyretin History Received 16 June 2014 Revised 4 December 2014 Accepted 8 December 2014 Published online 27 May 2015
Abbreviations: BNP: brain natriuretic peptide; CMAP: compound muscle action potential; CNS: central nervous system; EF: ejection fraction; hANP: human atrial natriuretic peptide; IVS: intraventricular septum; LVPW: left ventricular posterior wall; mBMI: modified body mass index; NIS+7: neuropathy Impairment Score plus 7; NSAID: non-steroidal anti-inflammatory drug; SF-36: 36-Item Short Form Health Survey; TTR: transthyretin
Introduction Hereditary ATTR amyloidosis (MIM 105210) is an autosomal dominant genetic disorder with life-threatening systemic deposition of amyloid fibrils induced by transthyretin (TTR) gene mutation [1,2]. Hereditary ATTR amyloidosis is characterized by slowly progressive nerve length-dependent sensorimotor and autonomic neuropathy as well as nonneuropathic changes of cardiomyopathy, nephropathy, ocular amyloidosis, and central nervous system (CNS) amyloidosis. Hereditary ATTR amyloidosis was regarded as a rare endemic disease, but it appears to be more common in the worldwide population than previously recognized. To date, over 100 mutations in the TTR gene have been shown to be associated with amyloidosis [3,4]. While the current standard form of Address for correspondence: Yoshiki Sekijima, Department of Medicine (Neurology and Rheumatology), Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto 390-8621, Japan. Tel: +81-263-37-2673. Fax: +81-263-37-3427. E-mail: [email protected]
care for hereditary ATTR amyloidosis patients is liver transplantation [5,6], it has a number of limitations, including requirement of invasive surgery, the need for long-term posttransplantation immunosuppressive therapy, and progression of eye [7], CNS [7], and cardiac amyloidosis [8,9] after transplantation. Furthermore, many hereditary ATTR amyloidosis patients are not good transplant candidates because of their age and/or advanced disease status. Therefore, it is desirable to develop a general, convenient, and non-invasive alternative therapeutic strategy to ameliorate hereditary ATTR amyloidosis [2,10]. Mutations in TTR destabilize its tetrameric structure, promoting TTR dissociation, misfolding and misassembly into oligomeric aggregates, including amyloid fibrils [11,12]. Stabilization of the TTR tetramer by small molecule binding to the thyroxine binding site raises the kinetic barrier of tetramer dissociation, preventing amyloidogenesis in vitro [13,14]. Recently, two TTR tetramer stabilizers, tafamidis [15] and diflunisal [16–18], were shown to inhibit polyneuropathy
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progression and preserve quality of life in patients with hereditary ATTR amyloidosis [19,20]. The observation periods of randomized controlled studies of tafamidis [19] and diflunisal [20] were 18 months and 24 months, respectively. In addition, Coelho et al. [21] reported the long-term safety and efficacy of tafamids in a 12-month open-label extension study. However, the long-term outcome of diflunissal is unknown. Here, we investigated the safety, drug tolerance, and efficacy of long-term administration of diflunisal in hereditary ATTR amyloidosis patients.
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Methods We recruited patients with hereditary ATTR amyloidosis at Shinshu University Hospital. Patients were eligible for the study if they were over 20 years of age, had biopsy proven amyloid deposition by Congo Red staining and mutant TTR genopositivity by DNA sequence analysis, exhibited signs of peripheral or autonomic neuropathy. Exclusions included non-ATTR amyloidosis, other causes of sensorimotor polyneuropathy, liver transplantation planned within 1 year, prior liver transplantation, severe congestive heart failure (class IV New York Heart Association), renal insufficiency (estimated creatinine clearance 530 mL/min), liver dysfunction (AST, ALT or total bilirubin 4twice the upper limit normal range), active gastrointestinal bleeding, thrombocytopenia (platelets5100 000/mL), non-steroidal or aspirin hypersensitivity, and pregnancy. A total of 40 Japanese patients were enrolled in the study. The subjects consisted of 28 men and 12 women ranging in age from 25 to 80 years (mean 60.7 ± 14.4 years old). The observation period ranged from 2 to 116 months (mean ± SD: 38.0 ± 31.2 months). Genotypes of TTR were as follows: Val30Met (p.Val50Met) heterozygous, n ¼ 30; Asp38Ala (p.Asp58Ala) heterozygous, n ¼ 3; Phe44Ser (p.Phe64Ser) heterozygous, n ¼ 2; Ser50Ile (p.Ser70Ile) heterozygous, n ¼ 2; Glu54Lys (p.Glu74Lys) heterozygous, n ¼ 1; Ile84Asn (p.Ile104Asn) heterozygous, n ¼ 1; Val107Ile (p.Val127Ile) heterozygous, n ¼ 1. Baseline demographic and clinical characteristics are shown in Table 1. After a baseline examination, diflunisal at 500 mg/day (250 mg bid) was administered orally to the patients. Histamine type-2 receptor antagonist or proton pump inhibitor was also administered in combination with diflunisal to prevent gastrointestinal bleeding. Ulnar and tibial nerve conduction velocities and compound muscle action potential (CMAP) amplitudes, clinical FAP score (Kumamoto score) [22,23], serum TTR concentration, modified body mass index (mBMI), plasma brain natriuretic peptide (BNP), and human atrial natriuretic peptide (hANP) concentrations, and echocardiographic parameters, including intraventricular septum (IVS) thickness, left ventricular posterior wall (LVPW) thickness, and ejection fraction (EF), were monitored every 12 months to evaluate the effects of diflunisal. Routine physical examination and blood tests were performed every 2 months to monitor adverse events. Serum concentration of TTR at baseline and after 12 months of treatment were compared by the paired t-test. Differences between disease progression from baseline to 24 months and that after 24 months were assessed using the Mann–Whitney U test. All statistical analyses were conducted
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Table 1. Baseline demographic and clinical characteristics. Characteristics Age, mean (SD), years old Sex, no. (%) Male Female TTR genotype, no. (%) Val30Met Non-Val30Met Disease stage based on PND, no. (%) I II IIIA IIIB IV Cardiomyopathy, no. (%) Cardiac conduction block, no. (%) Gastrointestinal symptoms, no. (%) Clinical FAP score, mean (SD) Modified BMI, mean (SD) Ulnar nerve CMAP amplitude, mean (SD), mV Tibial nerve CMAP amplitude, mean (SD), mV Plasma BNP level, mean (SD), pg/mL Plasma hANP level, mean (SD), pg/mL IVS thickness, mean (SD), mm LVPW thickness, mean (SD), mm Ejection fraction, mean (SD), % Serum creatinine level, mean (SD), mg/dL
n ¼ 40 60.7 (14.4) 28 (70.0) 12 (30.0) 30 (75.0) 10 (25.0) 10 12 8 7 3 34 18 22 17.9 838.7 4.8 3.5 135.7 55.0 16.7 14.5 68.9 0.72
(25.0) (30.0) (20.0) (17.5) (7.5) (85) (45) (55) (12.0) (171.7) (3.3) (5.6) (147.1) (46.2) (4.6) (3.3) (10.3) (0.16)
TTR, transthyretin; PND, polyneuropathy disability; FAP, familial amyloid polyneuropathy; mBMI, modified body mass index; CMAP, compound muscle action potential; BNP, brain natriuretic peptide; hANP, human atrial natriuretic peptide; IVS, intraventricular septum; LVPW, left ventricular posterior wall.
using SPSS version 18.0J software (SPSS Inc., Chicago, IL). In all analyses, p50.05 was taken to indicate statistical significance. This study (UMIN000001825) was approved by the Ethical Committee of Shinshu University School of Medicine and written informed consent was obtained from each patient.
Results Three patients dropped out due to diflunisal-related adverse events, including deterioration of renal function (n ¼ 2) and thrombocytopenia (n ¼ 1); patients recovered from these adverse events shortly after discontinuation of the study drug. Detailed information on diflunisal-related adverse events is shown in Supplemental Tables 1 and 2. Ten patients dropped out due to other reasons, including sepsis (n ¼ 2), pneumonia (n ¼ 1) lung cancer (n ¼ 1), renal cell cancer (n ¼ 1), cardiogenic brain embolism (n ¼ 1), and non-medical reasons (n ¼ 4) unrelated to diflunisal. Three deaths were reported with two occurring off study drug. Numbers of evaluable patients at 12, 24, and 36 months or later were 28, 21, and 16, respectively (Tables 2 and 3). Orally administered diflunisal significantly increased serum TTR concentration (21.8 ± 5.2 mg/dL at baseline, 28.1 ± 6.8 mg/dL at 12 months of treatment, p ¼ 0.000002) and stabilized TTR tetramer structure in each patient as described previously [17,18]. Clinical FAP score increased by 1.0/year (Table 2, Figure 1A), which was much better than natural history of hereditary ATTR amyloidosis reported by Berk et al. (3.3/ year) [20] and Tashima et al. (about 7/year) [23]. On the other
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Table 2. Change in outcome per year.
Clinical FAP score Modified BMI IVS + LVPW (mm) Ejection fraction (%)
Baseline to 12 months (n ¼ 28)
12 months to 24 months (n ¼ 21)
24 months to 36 months (n ¼ 16)
36 months to 48 months (n ¼ 14)
After 48 months (n ¼ 11)
Throughout the course (n ¼ 28)
0.74 ± 1.46 33.5 ± 56.0 0.64 ± 2.75 0.04 ± 6.99
1.48 ± 2.91 8.4 ± 63.8 0.17 ± 3.10 0.94 ± 5.95
0.63 ± 3.00 44.8 ± 95.2 0.64 ± 3.6 1.77 ± 6.04
1.57 ± 3.74 10.7 ± 96.6 0.49 ± 3.23 0.52 ± 6.62
0.87 ± 1.34 51.6 ± 56.8 0.18 ± 1.38 3.73 ± 6.97
0.98 ± 1.39 28.1 ± 25.6 0.25 ± 1.74 0.21 ± 3.76
FAP, familial amyloid polyneuropathy; mBMI, modified body mass index; IVS, intra-ventricular septum; LVPW, left ventricular posterior wall.
Ulnar nerve CMAP Tibial nerve CMAP Plasma BNP Plasma hANP
Baseline to 12 months (n ¼ 28)
12 Months to 24 months (n ¼ 21)
24 Months to 36 months (n ¼ 16)
36 Months to 48 months (n ¼ 14)
After 48 months (n ¼ 11)
Throughout the course (n ¼ 28)
15.4 ± 33.0 23.9 ± 59.2 30.9 ± 69.6 41.2 ± 87.5
1.8 ± 39.3 26.6 ± 35.1 11.2 ± 49.6 17.0 ± 74.0
16.3 ± 48.1 3.6 ± 71.2 24.2 ± 62.1 14.1 ± 66.0
22.9 ± 38.7 43.9 ± 36.3 30.0 ± 81.4 19.5 ± 42.8
2.7 ± 19.6 4.2 ± 25.3 6.4 ± 27.9 11.8 ± 29.2
6.7 ± 18.1 29.2 ± 38.6 11.7 ± 42.5 11.7 ± 32.7
CMAP, compound muscle action potential; BNP, brain natriuretic peptide; hANP, human atrial natriuretic peptide.
0
−20
−40
−60
−80
before after throughout 24 months 24 months the course
80
60
40
20
0 before after throughout 24 months 24 months the course
80
(%) 0
20
0
−20
60
40
20
0 before after throughout 24 months 24 months the course
−40
−60
before after throughout 24 months 24 months the course
(G) p = 0.96
−20
−80
−40
p = 0.41 before after throughout 24 months 24 months the course
(F) (%) p = 0.96
% change of plasma hANP per year (mean ± SD)
(E) (%)
(D)
40 % change of tibial nerve CMAP amplitude per year (mean ± SD)
1
0
p = 0.07
(H)
(mm) 4
p = 0.30
2
0
−2
−4
before after throughout 24 months 24 months the course
change of EF per year (mean ± SD)
2
(%)
% change of ulnar nerve CMAP amplitude per year(mean ± SD)
p = 0.79 3
(C)
change of IVS+LVPW thickness per yea r(mean ± SD)
4
change of mBMIper year(mean ± SD)
(B)
change of clinical FAP score per year (mean ± SD)
(A)
% change of plasma BNP per year (mean ± SD)
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Table 3. Percent changes in outcome per year.
p = 0.77 before after throughout 24 months 24 months the course
(%) 6 p = 0.23 3
0
−3
−6
before after throughout 24 months 24 months the course
Figure 1. Deterioration rates (per year) of (A) clinical FAP score, (B) mBMI, (C) ulnar and (D) tibial CMAP amplitude, (E) plasma BNP and (F) hANP, (G) IVS and LVPW thickness, and (H) EF are shown. Black, white, and gray bars indicate deterioration rate before 24 months, after 24 months, and throughout the course, respectively. FAP, familial amyloid polyneuropathy; mBMI, modified body mass index; CMAP, compound muscle action potential; BNP, brain natriuretic peptide; hANP, human atrial natriuretic peptide; IVS, intraventricular septum; LVPW, left ventricular posterior wall; EF, ejection fraction.
hand, mBMI decreased by 28.5/year (Table 2, Figure 1B), which was nearly identical to the natural course of hereditary ATTR amyloidosis reported in the tafamidis (20.7/year) and diflunisal (34.0/year) trials [19,20]. Nausea and/or vomiting improved in two patients and deteriorated in four patients during the study period, while diarrhea and/or constipation
improved in one patient and deteriorated in two patients. Ulnar and tibial nerve CMAP amplitude (Table 3, Figure 1C and D) and cardiological parameters (Tables 2 and 3, Figure 1E–H) deteriorated throughout the course. Longitudinal analyses examining data collected at baseline, 24 months, and after 24 months confirmed the sustaining
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effects of diflunisal on both neurological and cardiac functions. Deterioration rates of clinical FAP score, ulnar and tibial nerve CMAP amplitude, serum BNP and hANP, cardiac wall thickness, and EF were smaller after 2 years of treatment, although these differences were not statistically significant (Figure 1). In particular, ulnar CMAP amplitude increased by 5.4%/year, cardiac wall (IVS + LVPW) thickness decreased by 0.2 mm/year, and EF increased by 0.4%/year after 24 months of treatment (Figure 1C, G, H).
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Discussion Diflunisal is a well-known non-steroidal anti-inflammatory drug (NSAID) that has already been approved as a prescription drug in more than 40 countries. A recently reported randomized double-blind placebo-controlled trial of diflunisal [20] showed a significant beneficial effect of diflunisal at 2 years detected by multiple measures, including Neuropathy Impairment Score plus 7 (NIS + 7), clinical FAP score, mBMI, and the 36-Item Short Form Health Survey (SF-36). Although we did not analyze NIS + 7 and SF-36, the deterioration rate of clinical FAP score in our diflunisaltreated hereditary ATTR amyloidosis patients (1.0/year) was nearly identical to that in the previous clinical trial of this drug (1.4/year) [20] and much better than the natural history of untreated hereditary ATTR amyloidosis (3.3–7/year) [20,23]. In addition, deterioration rates of clinical FAP score were lower after 2 years of treatment, suggesting sustaining effects of diflunisal. Longitudinal analyses of ulnar and tibial nerve CMAP amplitude, plasma BNP and hANP, cardiac wall thickness, and EF also demonstrated sustaining effects of diflunisal on both neurological and cardiac functions. Notably, ulnar CMAP amplitude, cardiac wall thickness, and EF did not show deterioration at all after 24 months of treatment (Figure 1C, G, H). The only exception was mBMI, which deteriorated consistently throughout the course. In contrast to our observations, tafamidis was reported to increase mBMI of hereditary ATTR amyloidosis patients in a randomized double-blind placebo-controlled trial [19]. Although the mechanism of action of diflunisal and tafamidis, stabilization of the TTR tetramer by binding to the thyroxine binding site, is identical, tafamidis may have additional effects that improve nutritional status of hereditary ATTR amyloidosis patients. It is likely that cyclooxygenase-1 inhibition activity of diflunisal (e.g. gastric mucosal injury) is related to decline of mBMI. Diflunisal was tolerated well by most hereditary ATTR amyloidosis patients, although three patients dropped out due to diflunisal-related adverse events. Two of the three patients discontinued diflunisal due to deterioration of renal function, one of the most common adverse events of NSAIDs, although renal adverse events occurred in similar numbers in both diflunisal and placebo treatment groups in a randomized controlled trial [20]. It is likely that Japanese hereditary ATTR amyloidosis patients could be more prone to develop diflunisal-induced renal dysfunction due to their low body weight. In summary, our data demonstrated that the clinical effects of diflunisal are sustained after 2 years of treatment. However, clinical symptoms deteriorated slowly in most patients,
Amyloid, 2015; 22(2): 79–83
indicating that diflunisal cannot stop disease progression of hereditary ATTR amyloidosis completely. Additional diseasemodifying therapies, such as small-interfering RNAs and antisense oligonucleotides, will be necessary to overcome the lethal amyloidosis.
Acknowledgements The authors thank Ms. E. Nomura for her technical assistance.
Declaration of interest The authors report no conflicts of interest. This study was supported by a Grant-in-aid for Scientific Research (23591237 to YS), a grant from Amyloidosis Research Committee, the Ministry of Health, Labour and Welfare, Japan, and a Group Research Grant for the Pathogenesis and Therapy for Intractable Neuropathy in Japan.
References 1. Andrade C. A peculiar form of peripheral neuropathy; familiar atypical generalized amyloidosis with special involvement of the peripheral nerves. Brain 1952;75:408–27. 2. Plante-Bordeneuve V, Said G. Familial amyloid polyneuropathy. Lancet Neurol 2011;10:1086–97. 3. Connors LH, Lim A, Prokaeva T, Roskens VA, Costello CE. Tabulation of human transthyretin (ttr) variants, 2003. Amyloid 2003;10:160–84. 4. Sekijima Y, Yoshida K, Tokuda T, Ikeda S. Familial transthyretin amyloidosis (January 2012). In: Genereviews at genetests: medical genetics information resource [database online]. Seattle: University of Washington; 1993–2012. Available from: http://www.ncbi.nlm. nih.gov/books/NBK1194/ [last accessed 15 May 2015]. 5. Holmgren G, Steen L, Ekstedt J, Groth CG, Ericzon BG, Eriksson S, Andersen O, et al. Biochemical effect of liver transplantation in two swedish patients with familial amyloidotic polyneuropathy (fap-met30). Clin Genet 1991;40:242–6. 6. Holmgren G, Ericzon BG, Groth CG, Steen L, Suhr O, Andersen O, Wallin BG, et al. Clinical improvement and amyloid regression after liver-transplantation in hereditary transthyretin amyloidosis. Lancet 1993;341:1113–16. 7. Ando Y, Terazaki H, Nakamura M, Ando E, Haraoka K, Yamashita T, Ueda M, et al. A different amyloid formation mechanism: de novo oculoleptomeningeal amyloid deposits after liver transplantation. Transplantation 2004;77:345–9. 8. Dubrey SW, Davidoff R, Skinner M, Bergethon P, Lewis D, Falk RH. Progression of ventricular wall thickening after liver transplantation for familial amyloidosis. Transplantation 1997;64: 74–80. 9. Yazaki M, Tokuda T, Nakamura A, Higashikata T, Koyama J, Higuchi K, Harihara Y, et al. Cardiac amyloid in patients with familial amyloid polyneuropathy consists of abundant wildtype transthyretin. Biochem Biophys Res Commun 2000;274: 702–6. 10. Sekijima Y, Kelly JW, Ikeda S. Pathogenesis of and therapeutic strategies to ameliorate the transthyretin amyloidoses. Curr Pharm Des 2008;14:3219–30. 11. Hammarstrom P, Jiang X, Hurshman AR, Powers ET, Kelly JW. Sequence-dependent denaturation energetics: a major determinant in amyloid disease diversity. Proc Natl Acad Sci USA 2002;99: 16427–32. 12. Sekijima Y, Wiseman RL, Matteson J, Hammarstrom P, Miller SR, Sawkar AR, Balch WE, et al. The biological and chemical basis for tissue-selective amyloid disease. Cell 2005;121:73–85. 13. Hammarstrom P, Wiseman RL, Powers ET, Kelly JW. Prevention of transthyretin amyloid disease by changing protein misfolding energetics. Science 2003;299:713–16. 14. Johnson SM, Wiseman RL, Sekijima Y, Green NS, AdamskiWerner SL, Kelly JW. Native state kinetic stabilization as a strategy
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to ameliorate protein misfolding diseases: a focus on the transthyretin amyloidoses. Acc Chem Res 2005;38:911–21. Bulawa CE, Connelly S, Devit M, Wang L, Weigel C, Fleming JA, Packman J, et al. Tafamidis, a potent and selective transthyretin kinetic stabilizer that inhibits the amyloid cascade. Proc Natl Acad Sci USA 2012;109:9629–34. Miller SR, Sekijima Y, Kelly JW. Native state stabilization by nsaids inhibits transthyretin amyloidogenesis from the most common familial disease variants. Lab Invest 2004;84:545–52. Sekijima Y, Dendle MA, Kelly JW. Orally administered diflunisal stabilizes transthyretin against dissociation required for amyloidogenesis. Amyloid 2006;13:236–49. Tojo K, Sekijima Y, Kelly JW, Ikeda SI. Diflunisal stabilizes familial amyloid polyneuropathy-associated transthyretin variant tetramers in serum against dissociation required for amyloidogenesis. Neurosci Res 2006;56:441–9. Coelho T, Maia LF, Martins da Silva A, Waddington Cruz M, Plante-Bordeneuve V, Lozeron P, Suhr OB, et al. Tafamidis for
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transthyretin familial amyloid polyneuropathy: a randomized, controlled trial. Neurology 2012;79:785–92. Berk JL, Suhr OB, Obici L, Sekijima Y, Zeldenrust SR, Yamashita T, Heneghan MA, et al. Repurposing diflunisal for familial amyloid polyneuropathy: a randomized clinical trial. JAMA 2013;310:2658–67. Coelho T, Maia LF, da Silva AM, Cruz MW, Plante-Bordeneuve V, Suhr OB, Conceicao I, et al. Long-term effects of tafamidis for the treatment of transthyretin familial amyloid polyneuropathy. J Neurol 2013;260:2802–14. Tashima K, Ando Y, Ando E, Tanaka Y, Ando M, Uchino M. Heterogeneity of clinical symptoms in patients with familial amyloidotic polyneuropathy (fap ttr met30). Amyloid 1997;4: 108–11. Tashima K, Ando Y, Terazaki H, Yoshimatsu S, Suhr OB, Obayashi K, Yamashita T, et al. Outcome of liver transplantation for transthyretin amyloidosis: follow-up of japanese familial amyloidotic polyneuropathy patients. J Neurol Sci 1999;171:19–23.
Supplementary data available online Supplemental Table S1. Detailed information on diflunisal-related renal dysfunction. Supplemental Table S2. Detailed information on diflunisal-related thrombocytopenia.
ORIGINAL ARTICLE
Safety and efficacy of long-term diflunisal administration in hereditary transthyretin (ATTR) amyloidosis Yoshiki Sekijima1,2, Kana Tojo1, Hiroshi Morita1, Jun Koyama3, and Shu-ichi Ikeda1,2 Department of Medicine (Neurology and Rheumatology), Shinshu University School of Medicine, Matsumoto, Japan, 2Institute for Biomedical Sciences, Shinshu University, Matsumoto, Japan, and 3Department of Cardiovascular Medicine, Shinshu University School of Medicine, Matsumoto, Japan
Amyloid Downloaded from informahealthcare.com by University of Otago on 07/13/15 For personal use only.
1
Abstract
Keywords
Background: A recent 2-year randomized controlled trial indicated that the transthyretin (TTR) tetramer stabilizer, diflunisal, inhibits polyneuropathy progression and preserves quality of life in hereditary ATTR amyloidosis. However, its long-term outcomes are unknown. Here, we report tolerance and efficacy of long-term diflunisal administration in hereditary ATTR amyloidosis. Methods: Diflunisal was administered orally at 500 mg/day to 40 Japanese hereditary ATTR amyloidosis patents who were not candidates for liver transplantation. The observation period ranged from 2 to 116 months (mean ± SD: 38.0 ± 31.2 months). Results: Diflunisal-related adverse events included deterioration of renal function and thrombocytopenia resulting in discontinuation of the drug in three patients. Orally administered diflunisal significantly increased serum TTR concentration (p ¼ 0.001) and stabilized TTR tetramer structure in each patient. Longitudinal analyses of data collected at baseline, 24 months, and after 24 months confirmed sustaining effects of diflunisal on both neurological and cardiac functions. Notably, ulnar compound muscle action potential amplitude, cardiac wall thickness, and ejection fraction were not deteriorated after 24 months of treatment. Conclusions: Diflunisal was tolerated well by most hereditary ATTR amyloidosis patients, although renal function and blood cell counts must be carefully monitored. Clinical effects of diflunisal were sustained after 2 years of treatment.
Amyloid, clinical trial, diflunisal, familial amyloid polyneuropathy, hereditary ATTR amyloidosis, transthyretin History Received 16 June 2014 Revised 4 December 2014 Accepted 8 December 2014 Published online 27 May 2015
Abbreviations: BNP: brain natriuretic peptide; CMAP: compound muscle action potential; CNS: central nervous system; EF: ejection fraction; hANP: human atrial natriuretic peptide; IVS: intraventricular septum; LVPW: left ventricular posterior wall; mBMI: modified body mass index; NIS+7: neuropathy Impairment Score plus 7; NSAID: non-steroidal anti-inflammatory drug; SF-36: 36-Item Short Form Health Survey; TTR: transthyretin
Introduction Hereditary ATTR amyloidosis (MIM 105210) is an autosomal dominant genetic disorder with life-threatening systemic deposition of amyloid fibrils induced by transthyretin (TTR) gene mutation [1,2]. Hereditary ATTR amyloidosis is characterized by slowly progressive nerve length-dependent sensorimotor and autonomic neuropathy as well as nonneuropathic changes of cardiomyopathy, nephropathy, ocular amyloidosis, and central nervous system (CNS) amyloidosis. Hereditary ATTR amyloidosis was regarded as a rare endemic disease, but it appears to be more common in the worldwide population than previously recognized. To date, over 100 mutations in the TTR gene have been shown to be associated with amyloidosis [3,4]. While the current standard form of Address for correspondence: Yoshiki Sekijima, Department of Medicine (Neurology and Rheumatology), Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto 390-8621, Japan. Tel: +81-263-37-2673. Fax: +81-263-37-3427. E-mail: [email protected]
care for hereditary ATTR amyloidosis patients is liver transplantation [5,6], it has a number of limitations, including requirement of invasive surgery, the need for long-term posttransplantation immunosuppressive therapy, and progression of eye [7], CNS [7], and cardiac amyloidosis [8,9] after transplantation. Furthermore, many hereditary ATTR amyloidosis patients are not good transplant candidates because of their age and/or advanced disease status. Therefore, it is desirable to develop a general, convenient, and non-invasive alternative therapeutic strategy to ameliorate hereditary ATTR amyloidosis [2,10]. Mutations in TTR destabilize its tetrameric structure, promoting TTR dissociation, misfolding and misassembly into oligomeric aggregates, including amyloid fibrils [11,12]. Stabilization of the TTR tetramer by small molecule binding to the thyroxine binding site raises the kinetic barrier of tetramer dissociation, preventing amyloidogenesis in vitro [13,14]. Recently, two TTR tetramer stabilizers, tafamidis [15] and diflunisal [16–18], were shown to inhibit polyneuropathy
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progression and preserve quality of life in patients with hereditary ATTR amyloidosis [19,20]. The observation periods of randomized controlled studies of tafamidis [19] and diflunisal [20] were 18 months and 24 months, respectively. In addition, Coelho et al. [21] reported the long-term safety and efficacy of tafamids in a 12-month open-label extension study. However, the long-term outcome of diflunissal is unknown. Here, we investigated the safety, drug tolerance, and efficacy of long-term administration of diflunisal in hereditary ATTR amyloidosis patients.
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Methods We recruited patients with hereditary ATTR amyloidosis at Shinshu University Hospital. Patients were eligible for the study if they were over 20 years of age, had biopsy proven amyloid deposition by Congo Red staining and mutant TTR genopositivity by DNA sequence analysis, exhibited signs of peripheral or autonomic neuropathy. Exclusions included non-ATTR amyloidosis, other causes of sensorimotor polyneuropathy, liver transplantation planned within 1 year, prior liver transplantation, severe congestive heart failure (class IV New York Heart Association), renal insufficiency (estimated creatinine clearance 530 mL/min), liver dysfunction (AST, ALT or total bilirubin 4twice the upper limit normal range), active gastrointestinal bleeding, thrombocytopenia (platelets5100 000/mL), non-steroidal or aspirin hypersensitivity, and pregnancy. A total of 40 Japanese patients were enrolled in the study. The subjects consisted of 28 men and 12 women ranging in age from 25 to 80 years (mean 60.7 ± 14.4 years old). The observation period ranged from 2 to 116 months (mean ± SD: 38.0 ± 31.2 months). Genotypes of TTR were as follows: Val30Met (p.Val50Met) heterozygous, n ¼ 30; Asp38Ala (p.Asp58Ala) heterozygous, n ¼ 3; Phe44Ser (p.Phe64Ser) heterozygous, n ¼ 2; Ser50Ile (p.Ser70Ile) heterozygous, n ¼ 2; Glu54Lys (p.Glu74Lys) heterozygous, n ¼ 1; Ile84Asn (p.Ile104Asn) heterozygous, n ¼ 1; Val107Ile (p.Val127Ile) heterozygous, n ¼ 1. Baseline demographic and clinical characteristics are shown in Table 1. After a baseline examination, diflunisal at 500 mg/day (250 mg bid) was administered orally to the patients. Histamine type-2 receptor antagonist or proton pump inhibitor was also administered in combination with diflunisal to prevent gastrointestinal bleeding. Ulnar and tibial nerve conduction velocities and compound muscle action potential (CMAP) amplitudes, clinical FAP score (Kumamoto score) [22,23], serum TTR concentration, modified body mass index (mBMI), plasma brain natriuretic peptide (BNP), and human atrial natriuretic peptide (hANP) concentrations, and echocardiographic parameters, including intraventricular septum (IVS) thickness, left ventricular posterior wall (LVPW) thickness, and ejection fraction (EF), were monitored every 12 months to evaluate the effects of diflunisal. Routine physical examination and blood tests were performed every 2 months to monitor adverse events. Serum concentration of TTR at baseline and after 12 months of treatment were compared by the paired t-test. Differences between disease progression from baseline to 24 months and that after 24 months were assessed using the Mann–Whitney U test. All statistical analyses were conducted
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Table 1. Baseline demographic and clinical characteristics. Characteristics Age, mean (SD), years old Sex, no. (%) Male Female TTR genotype, no. (%) Val30Met Non-Val30Met Disease stage based on PND, no. (%) I II IIIA IIIB IV Cardiomyopathy, no. (%) Cardiac conduction block, no. (%) Gastrointestinal symptoms, no. (%) Clinical FAP score, mean (SD) Modified BMI, mean (SD) Ulnar nerve CMAP amplitude, mean (SD), mV Tibial nerve CMAP amplitude, mean (SD), mV Plasma BNP level, mean (SD), pg/mL Plasma hANP level, mean (SD), pg/mL IVS thickness, mean (SD), mm LVPW thickness, mean (SD), mm Ejection fraction, mean (SD), % Serum creatinine level, mean (SD), mg/dL
n ¼ 40 60.7 (14.4) 28 (70.0) 12 (30.0) 30 (75.0) 10 (25.0) 10 12 8 7 3 34 18 22 17.9 838.7 4.8 3.5 135.7 55.0 16.7 14.5 68.9 0.72
(25.0) (30.0) (20.0) (17.5) (7.5) (85) (45) (55) (12.0) (171.7) (3.3) (5.6) (147.1) (46.2) (4.6) (3.3) (10.3) (0.16)
TTR, transthyretin; PND, polyneuropathy disability; FAP, familial amyloid polyneuropathy; mBMI, modified body mass index; CMAP, compound muscle action potential; BNP, brain natriuretic peptide; hANP, human atrial natriuretic peptide; IVS, intraventricular septum; LVPW, left ventricular posterior wall.
using SPSS version 18.0J software (SPSS Inc., Chicago, IL). In all analyses, p50.05 was taken to indicate statistical significance. This study (UMIN000001825) was approved by the Ethical Committee of Shinshu University School of Medicine and written informed consent was obtained from each patient.
Results Three patients dropped out due to diflunisal-related adverse events, including deterioration of renal function (n ¼ 2) and thrombocytopenia (n ¼ 1); patients recovered from these adverse events shortly after discontinuation of the study drug. Detailed information on diflunisal-related adverse events is shown in Supplemental Tables 1 and 2. Ten patients dropped out due to other reasons, including sepsis (n ¼ 2), pneumonia (n ¼ 1) lung cancer (n ¼ 1), renal cell cancer (n ¼ 1), cardiogenic brain embolism (n ¼ 1), and non-medical reasons (n ¼ 4) unrelated to diflunisal. Three deaths were reported with two occurring off study drug. Numbers of evaluable patients at 12, 24, and 36 months or later were 28, 21, and 16, respectively (Tables 2 and 3). Orally administered diflunisal significantly increased serum TTR concentration (21.8 ± 5.2 mg/dL at baseline, 28.1 ± 6.8 mg/dL at 12 months of treatment, p ¼ 0.000002) and stabilized TTR tetramer structure in each patient as described previously [17,18]. Clinical FAP score increased by 1.0/year (Table 2, Figure 1A), which was much better than natural history of hereditary ATTR amyloidosis reported by Berk et al. (3.3/ year) [20] and Tashima et al. (about 7/year) [23]. On the other
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Table 2. Change in outcome per year.
Clinical FAP score Modified BMI IVS + LVPW (mm) Ejection fraction (%)
Baseline to 12 months (n ¼ 28)
12 months to 24 months (n ¼ 21)
24 months to 36 months (n ¼ 16)
36 months to 48 months (n ¼ 14)
After 48 months (n ¼ 11)
Throughout the course (n ¼ 28)
0.74 ± 1.46 33.5 ± 56.0 0.64 ± 2.75 0.04 ± 6.99
1.48 ± 2.91 8.4 ± 63.8 0.17 ± 3.10 0.94 ± 5.95
0.63 ± 3.00 44.8 ± 95.2 0.64 ± 3.6 1.77 ± 6.04
1.57 ± 3.74 10.7 ± 96.6 0.49 ± 3.23 0.52 ± 6.62
0.87 ± 1.34 51.6 ± 56.8 0.18 ± 1.38 3.73 ± 6.97
0.98 ± 1.39 28.1 ± 25.6 0.25 ± 1.74 0.21 ± 3.76
FAP, familial amyloid polyneuropathy; mBMI, modified body mass index; IVS, intra-ventricular septum; LVPW, left ventricular posterior wall.
Ulnar nerve CMAP Tibial nerve CMAP Plasma BNP Plasma hANP
Baseline to 12 months (n ¼ 28)
12 Months to 24 months (n ¼ 21)
24 Months to 36 months (n ¼ 16)
36 Months to 48 months (n ¼ 14)
After 48 months (n ¼ 11)
Throughout the course (n ¼ 28)
15.4 ± 33.0 23.9 ± 59.2 30.9 ± 69.6 41.2 ± 87.5
1.8 ± 39.3 26.6 ± 35.1 11.2 ± 49.6 17.0 ± 74.0
16.3 ± 48.1 3.6 ± 71.2 24.2 ± 62.1 14.1 ± 66.0
22.9 ± 38.7 43.9 ± 36.3 30.0 ± 81.4 19.5 ± 42.8
2.7 ± 19.6 4.2 ± 25.3 6.4 ± 27.9 11.8 ± 29.2
6.7 ± 18.1 29.2 ± 38.6 11.7 ± 42.5 11.7 ± 32.7
CMAP, compound muscle action potential; BNP, brain natriuretic peptide; hANP, human atrial natriuretic peptide.
0
−20
−40
−60
−80
before after throughout 24 months 24 months the course
80
60
40
20
0 before after throughout 24 months 24 months the course
80
(%) 0
20
0
−20
60
40
20
0 before after throughout 24 months 24 months the course
−40
−60
before after throughout 24 months 24 months the course
(G) p = 0.96
−20
−80
−40
p = 0.41 before after throughout 24 months 24 months the course
(F) (%) p = 0.96
% change of plasma hANP per year (mean ± SD)
(E) (%)
(D)
40 % change of tibial nerve CMAP amplitude per year (mean ± SD)
1
0
p = 0.07
(H)
(mm) 4
p = 0.30
2
0
−2
−4
before after throughout 24 months 24 months the course
change of EF per year (mean ± SD)
2
(%)
% change of ulnar nerve CMAP amplitude per year(mean ± SD)
p = 0.79 3
(C)
change of IVS+LVPW thickness per yea r(mean ± SD)
4
change of mBMIper year(mean ± SD)
(B)
change of clinical FAP score per year (mean ± SD)
(A)
% change of plasma BNP per year (mean ± SD)
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Table 3. Percent changes in outcome per year.
p = 0.77 before after throughout 24 months 24 months the course
(%) 6 p = 0.23 3
0
−3
−6
before after throughout 24 months 24 months the course
Figure 1. Deterioration rates (per year) of (A) clinical FAP score, (B) mBMI, (C) ulnar and (D) tibial CMAP amplitude, (E) plasma BNP and (F) hANP, (G) IVS and LVPW thickness, and (H) EF are shown. Black, white, and gray bars indicate deterioration rate before 24 months, after 24 months, and throughout the course, respectively. FAP, familial amyloid polyneuropathy; mBMI, modified body mass index; CMAP, compound muscle action potential; BNP, brain natriuretic peptide; hANP, human atrial natriuretic peptide; IVS, intraventricular septum; LVPW, left ventricular posterior wall; EF, ejection fraction.
hand, mBMI decreased by 28.5/year (Table 2, Figure 1B), which was nearly identical to the natural course of hereditary ATTR amyloidosis reported in the tafamidis (20.7/year) and diflunisal (34.0/year) trials [19,20]. Nausea and/or vomiting improved in two patients and deteriorated in four patients during the study period, while diarrhea and/or constipation
improved in one patient and deteriorated in two patients. Ulnar and tibial nerve CMAP amplitude (Table 3, Figure 1C and D) and cardiological parameters (Tables 2 and 3, Figure 1E–H) deteriorated throughout the course. Longitudinal analyses examining data collected at baseline, 24 months, and after 24 months confirmed the sustaining
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effects of diflunisal on both neurological and cardiac functions. Deterioration rates of clinical FAP score, ulnar and tibial nerve CMAP amplitude, serum BNP and hANP, cardiac wall thickness, and EF were smaller after 2 years of treatment, although these differences were not statistically significant (Figure 1). In particular, ulnar CMAP amplitude increased by 5.4%/year, cardiac wall (IVS + LVPW) thickness decreased by 0.2 mm/year, and EF increased by 0.4%/year after 24 months of treatment (Figure 1C, G, H).
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Discussion Diflunisal is a well-known non-steroidal anti-inflammatory drug (NSAID) that has already been approved as a prescription drug in more than 40 countries. A recently reported randomized double-blind placebo-controlled trial of diflunisal [20] showed a significant beneficial effect of diflunisal at 2 years detected by multiple measures, including Neuropathy Impairment Score plus 7 (NIS + 7), clinical FAP score, mBMI, and the 36-Item Short Form Health Survey (SF-36). Although we did not analyze NIS + 7 and SF-36, the deterioration rate of clinical FAP score in our diflunisaltreated hereditary ATTR amyloidosis patients (1.0/year) was nearly identical to that in the previous clinical trial of this drug (1.4/year) [20] and much better than the natural history of untreated hereditary ATTR amyloidosis (3.3–7/year) [20,23]. In addition, deterioration rates of clinical FAP score were lower after 2 years of treatment, suggesting sustaining effects of diflunisal. Longitudinal analyses of ulnar and tibial nerve CMAP amplitude, plasma BNP and hANP, cardiac wall thickness, and EF also demonstrated sustaining effects of diflunisal on both neurological and cardiac functions. Notably, ulnar CMAP amplitude, cardiac wall thickness, and EF did not show deterioration at all after 24 months of treatment (Figure 1C, G, H). The only exception was mBMI, which deteriorated consistently throughout the course. In contrast to our observations, tafamidis was reported to increase mBMI of hereditary ATTR amyloidosis patients in a randomized double-blind placebo-controlled trial [19]. Although the mechanism of action of diflunisal and tafamidis, stabilization of the TTR tetramer by binding to the thyroxine binding site, is identical, tafamidis may have additional effects that improve nutritional status of hereditary ATTR amyloidosis patients. It is likely that cyclooxygenase-1 inhibition activity of diflunisal (e.g. gastric mucosal injury) is related to decline of mBMI. Diflunisal was tolerated well by most hereditary ATTR amyloidosis patients, although three patients dropped out due to diflunisal-related adverse events. Two of the three patients discontinued diflunisal due to deterioration of renal function, one of the most common adverse events of NSAIDs, although renal adverse events occurred in similar numbers in both diflunisal and placebo treatment groups in a randomized controlled trial [20]. It is likely that Japanese hereditary ATTR amyloidosis patients could be more prone to develop diflunisal-induced renal dysfunction due to their low body weight. In summary, our data demonstrated that the clinical effects of diflunisal are sustained after 2 years of treatment. However, clinical symptoms deteriorated slowly in most patients,
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indicating that diflunisal cannot stop disease progression of hereditary ATTR amyloidosis completely. Additional diseasemodifying therapies, such as small-interfering RNAs and antisense oligonucleotides, will be necessary to overcome the lethal amyloidosis.
Acknowledgements The authors thank Ms. E. Nomura for her technical assistance.
Declaration of interest The authors report no conflicts of interest. This study was supported by a Grant-in-aid for Scientific Research (23591237 to YS), a grant from Amyloidosis Research Committee, the Ministry of Health, Labour and Welfare, Japan, and a Group Research Grant for the Pathogenesis and Therapy for Intractable Neuropathy in Japan.
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Supplementary data available online Supplemental Table S1. Detailed information on diflunisal-related renal dysfunction. Supplemental Table S2. Detailed information on diflunisal-related thrombocytopenia.
