Treatment of Wilson's disease with penicillamine

Trientine tetrahydrochloride versus penicillamine for maintenance therapy in Wilson disease (CHELATE): a randomised, open-label, non-inferiority, phase 3 trial

BACKGROUND

Wilson disease is an inherited disorder of copper transport. Whereas penicillamine is used therapeutically to re-establish copper balance, trientine is indicated for patients with penicillamine intolerance. We aimed to compare penicillamine with trientine tetrahydrochloride (TETA4) for maintenance therapy in patients with Wilson disease.

METHODS

We conducted a randomised, open-label, non-inferiority, phase 3 trial at 15 health-care centres across nine countries (patients were recruited from 13 of these health-care centres across Brazil, Europe, and the USA). We enrolled patients aged 18-75 years with stable Wilson disease who were treated for at least 1 year with penicillamine. Patients entered a 12-week period to determine stability through clinical assessment by site investigators and predefined thresholds for serum non-caeruloplasmin-bound copper (NCC; by an exchangeable copper assay; 25-150 μg/L), 24 h urinary copper excretion (100-900 μg/24 h), and alanine aminotransferase (ALT; <2 × upper limit of normal). Stable patients were randomly assigned (1:1) to continue receiving the maintenance twice daily dose of oral penicillamine or switched mg-for-mg to oral TETA4 centrally with a web-based system using minimisation. The primary endpoint, assessed 24 weeks after randomisation, was NCC by speciation assay. The non-inferiority margin of mean difference in NCC by speciation assay was -50 μg/L, as estimated by a general linear model for repeated visits, adjusted for baseline values. Further data on safety and efficacy were collected during a 24-week extension period. Data were analysed using an intention-to-treat approach. Safety was assessed in all patients who received at least one dose of study treatment. This study is registered with ClinicalTrials.gov, NCT03539952 (active, not recruiting).

FINDINGS

Between June 4, 2018, and March 10, 2020, 77 patients were screened. 53 patients were randomly assigned (27 to the penicillamine group and 26 to the TETA4 group). After 24 weeks, the mean difference in serum NCC by speciation assay between the penicillamine group and TETA4 group was -9·1 μg/L (95% CI -24·2 to 6·1), with the lower limit of the 95% CI within the defined non-inferiority margin. At 24 weeks, urinary copper excretion was lower with TETA4 than with penicillamine (mean difference 237·5 μg/24 h (99% CI 115·6 to 359·4). At 48 weeks, TETA4 remained non-inferior to penicillamine in terms of NCC by speciation assay (mean difference NCC -15·5 μg/L [95% CI -34·5 to 3·6]). Urinary copper excretion at 48 weeks remained in the expected range for well treated patients in both study groups, and the mean difference (124·8 μg/24 h [99% CI -37·6 to 287·1]) was not significantly different. At 24 weeks and 48 weeks, masked clinical adjudication of stability assessed by three independent clinicians confirmed clinical stability (100%) of all participants, in agreement with the stability seen with the NCC by speciation assay. There were no notable changes in either the Clinical Global Impression of Change or Unified Wilson Disease Rating Scale (neurological assessment) from baseline (pre-randomisation) at weeks 24 and 48. The mean change in serum total copper from baseline to 24 weeks was 17·6 μg/L (99% CI -9·5 to 44·7) with penicillamine and -6·3 μg/L (-34·7 to 22·1) with TETA4, and the mean change in serum total caeruloplasmin from baseline to 24 weeks was 1·8 mg/L (-19·2 to 22·8) with penicillamine and -2·2 mg/L (-6·1 to 1·7) with TETA4. All liver enzymes were similar at 24 weeks and 48 weeks, with the exception of elevated ALT concentration at 48 weeks for patients in the TETA4 group. Penicillamine was associated with three post-randomisation serious adverse events (leukopenia, cholangiocarcinoma, and hepatocellular cancer); none were reported for TETA4. The most common treatment-emergent adverse events were headache for penicillamine (five [19%] of 27 patients vs two [8%] of 26) and abdominal pain for TETA4 (one [4%] vs four [15%]); all treatment-emergent adverse events resolved and were mild to moderate. One patient developed a rash with TETA4 that resolved on discontinuation of therapy.

INTERPRETATION

The efficacy of TETA4 as oral maintenance therapy was non-inferior to penicillamine and well tolerated in adults with Wilson disease.

FUNDING

Orphalan.

Wilson Disease in Children

The silver anniversary of the discovery of the Wilson disease gene ATP7B was a couple of years ago, and we continue to make progress both in our understanding of copper transportation using animal models as well as earlier diagnosis by availing of genetic testing. Wilson disease is multisystemic and the hepatic manifestations are seen more frequently in childhood, whereas neurologic manifestations are more common in adults; presentation may range from subtle changes to end-stage liver disease with or without encephalopathy as well as neuropsychiatric manifestations. Treatment remains with zinc and chelating agents such as D-penicillamine and trientine but newer agents and gene therapy are in clinical trials. Liver transplantation becomes necessary when medical therapy is not enough. Molecular diagnosis and genetic counseling is important.

D-Penicillamine: The State of the Art in Humans and in Dogs from a Pharmacological and Regulatory Perspective

Chelant agents are the mainstay of treatment in copper-associated hepatitis in humans, where D-penicillamine is the chelant agent of first choice. In veterinary medicine, the use of D-penicillamine has increased with the recent recognition of copper-associated hepatopathies that occur in several breeds of dogs. Although the different regulatory authorities in the world (United States Food and Drugs Administration-U.S. FDA, European Medicines Agency-EMEA, etc.) do not approve D-penicillamine for use in dogs, it has been used to treat copper-associated hepatitis in dogs since the 1970s, and is prescribed legally by veterinarians as an extra-label drug to treat this disease and alleviate suffering. The present study aims to: (a) address the pharmacological features; (b) outline the clinical scenario underlying the increased interest in D-penicillamine by overviewing the evolution of its main therapeutic goals in humans and dogs; and finally, (c) provide a discussion on its use and prescription in veterinary medicine from a regulatory perspective.

Wilson's disease: the 60th anniversary of Walshe's article on treatment with penicillamine

This historical review describes Professor Walshe's seminal contribution to the treatment of Wilson's disease on the 60th anniversary of his pioneering article on penicillamine, the first effective treatment for the condition.

Wilson disease - currently used anticopper therapy

Wilson disease (WD) is a genetic disorder of copper metabolism that can be treated successfully with pharmacologic treatment. Two groups of drugs are currently used: chelators (e.g., d-penicillamine and trientine), which increase urinary copper excretion, and zinc salts, which inhibit copper absorption in the digestive tract. The mechanisms of action lead to a negative copper balance, stopping pathologic accumulation of copper in the tissues and clearing affected organs of copper overload. Due to a lack of prospective clinical trials, the use of drugs depends mainly on center experience and the accessibility in different countries or regions. This chapter presents the different reports and recommendations regarding WD treatment. In addition to the different expert opinions on pharmacologic agents, there are a few axioms regarding WD treatment: treatment should start immediately after diagnosis, even in clinically presymptomatic cases; the patient should be treated for life, making compliance a key factor in treatment success; and the treatment should be monitored regularly via liver and hematologic tests, neurologic examination, and copper metabolism, modifying the treatment accordingly. Other drugs proposed for WD treatment (e.g., tetrathiomolybdate) are in clinical trials and lack current recommendations. Thus, only the currently available options for WD pharmacologic treatment are discussed.

History of Wilson disease: a personal account

This chapter focuses on the historic aspects of the development of much of our current knowledge of the diagnosis and treatment of Wilson disease. Included are descriptions of the clinical signs of neurologic and hepatic disease, the natural history of disease progression, studies of disease pathogenesis and a unique perspective on the development of diagnostic testing and pharmacological therapy.

Ultrafast Photochemistry of Copper(II) Monochlorocomplexes in Methanol and Acetonitrile by Broadband Deep-UV-to-Near-IR Femtosecond Transient Absorption Spectroscopy

Photochemistry of copper(II) monochlorocomplexes in methanol and acetonitrile solutions is studied by UV-pump/broadband deep-UV-to-near-IR probe femtosecond transient absorption spectroscopy. Upon 255 and 266 nm excitation, the complexes in acetonitrile and methanol, respectively, are promoted to the excited ligand-to-metal charge transfer (LMCT) state, which has a short (sub-250 fs) lifetime. From the LMCT state, the complexes decay via internal conversion to lower-lying ligand field (LF) d-d excited states or the vibrationally hot ground electronic state. A minor fraction of the excited complexes relaxes to the LF electronic excited states, which are relatively long-lived with lifetimes >1 ns. Also, in methanol solutions, about 3% of the LMCT-excited copper(II) monochlorocomplexes dissociate forming copper(I) solvatocomplexes and chlorine atoms, which then further react forming long-lived photoproducts. In acetonitrile, about 50% of the LMCT-excited copper(II) monochlorocomplexes dissociate forming radical and ionic products in a ratio of 3:2. Another minor process observed following excitation only in methanol solutions is the re-equilibration between several forms of the copper(II) ground-state complexes present in solutions. This re-equilibration occurs on a time scale from sub-nanoseconds to nanoseconds.

The treatment of Wilson's disease, a rare genetic disorder of copper metabolism

Wilson's disease is a rare autosomal recessive disease characterised by the deposition of copper in the brain, liver; cornea, and other organs. The overload of copper inevitably leads to progressive liver and neurological dysfunction. Copper overload in patients with Wilson's disease is caused by impairment to the biliary route for excretion of dietary copper A combination of neurological, psychiatric and hepatic symptoms can make the diagnosis of Wilson's disease challenging. Most symptoms appear in the second and third decades of life. The disease affects between one in 30,000 and one in 100,000 individuals, and is fatal if left untreated. Five drugs are currently available to treat Wilson's disease: British Anti-Lewisite; D-penicillamine; trientine; zinc sulfate or acetate; and ammonium tetrathiomolybdate. Each drug can reduce copper levels and/or transform copper into a metabolically inert and unavailable form in the patient. The discovery and introduction of these five drugs owes more to the inspiration of a few dedicated physicians and agricultural scientists than to the resources of the pharmaceutical industry.

Chapter 33: the history of movement disorders

Role of basal ganglia: Vesalius and Piccolomini distinguished subcortical nuclei from cortex and white matter in the 16th century. Willis' mistaken concept in the late 17th century that the corpus striatum was the seat of motor power persisted for 200 years and formed the basis of mid-19th-century localizations of movement disorders to the striatum (chorea by Broadbent and Jackson, and athetosis by Hammond). By the late 19th century, many movement disorders were described but for most no pathologic correlate was known. Tremor: Descriptions of tremors progressed from Galen's definition in the 2nd century; to Galileo's physiologic tremor in 1610; separation of involuntary movements during action and at rest in the 17th and 18th centuries by de la Boë Sylvius and van Sweiten; description of Parkinson's disease by Parkinson, discrimination of the rest tremor of Parkinson's disease from the intention tremor of multiple sclerosis by Charcot, and recognition of familial action tremors by Dana and others in the late 19th century; and recognition of autosomal dominant essential tremor in the mid-20th century. Parkinsonism: Pathologic changes in Parkinson's disease were recognized in the substantia nigra by Blocq and Marinescu in the late 19th century, and around 1920 Trértiakoff established Lewy bodies in the substantia nigra as a pathologic hallmark while the Vogts instead emphasized pathologic changes in the striatum; it was only in the mid-1960s that a nigrostriatal dopaminergic pathway was demonstrated and found to be critical to pathogenesis. Early treatment approaches with anticholinergic medications or crude neurosurgical ablation procedures were eclipsed in the 1960s by the advent of L-DOPA therapy due to the work of Carlsson and colleagues, Birkmayer and Hornykiewicz, Barbeau, and Cotzias. Later progress in understanding and treating Parkinson's disease included recognition of neuroleptic-induced parkinsonism beginning in the 1950s, development of dopamine agonists and elaboration of different dopamine receptors beginning in the 1960s, recognition of MPTP-induced parkinsonism in 1982 and subsequent development of experimental models of MPTP-induced parkinsonism. Since the 1980s, stereotactic neurosurgical ablation procedures such as stereotactic pallidotomy were revisited and improved, and stimulation or ablation procedures that modulate subthalamic nucleus activity were developed. Since 1990, rare genetic forms of Parkinson's disease were discovered, which accelerated progress in understanding pathogenesis, and established roles for alpha synuclein and the ubiquitin-proteasome proteolytic system. Separation of atypical forms of parkinsonism (e.g. Wilson's disease, multisystem atrophy, progressive supranuclear palsy, and corticobasal degeneration) from Parkinson's disease in the 20th century also led to important discoveries of basal ganglia function, and in the case of Wilson's disease to recognition of genetic mutations and effective treatments. Choreoathetosis: Since the middle ages, the term chorea has been used to describe both organic and psychological disorders of motor control. Paracelcus introduced the concept of chorea as an organic medical condition in the 16th century. Sydenham's description of childhood chorea (1686) was followed by recognition in the 19th and 20th centuries that Sydenham's chorea was a manifestation of rheumatic fever; by the 1930s, rheumatic fever was recognized as a sequel of group A streptococcal pharyngitis, which could be effectively prevented with sulfonamides. Athetosis was described by Hammond (1871) and later linked by him to a malignant growth in the contralateral corpus striatum; nevertheless, athetosis has been controversial and often dismissed as a form of post-hemiplegic chorea or part of a continuum between chorea and dystonia. Huntington's classic description of adult-onset hereditary chorea (1872) was followed a century later by demonstration that Huntington's disease is caused by an unstable CAG trinucleotide repeat expansion in the Huntington disease gene on chromosome 4; this triggered a surge in research, development of various animal models, and numerous important discoveries of cell function and disease pathogenesis. Hemiballismus and the subthalamic nucleus: The relationship between a lesion of the subthalamic nucleus of Luys and contralateral hemiballismus was first convincingly demonstrated by Martin in 1927; this led 20 years later to development of an animal model by Whittier and Mettler, who produced experimental hemichorea-hemiballismus in monkeys by lesioning the contralateral subthalamic nucleus. Since the late 1980s, the neurochemistry and neurophysiology of the subthalamic nucleus have been substantially revised with the demonstration that the subthalamic nucleus is not fundamentally inhibitory but instead provides excitatory glutaminergic inputs to the globus pallidus, and appreciation that the subthalamic nucleus serves an important role in both hyperkinetic and hypokinetic movement disorders. Dystonia: Dystonias were often interpreted in psychological or psychiatric terms since the original descriptions of generalized dystonia by Barraquer Roviralta (1897), and familial forms of generalized primary tortion dystonia by Schwalbe (1908) and Oppenheim (1911). Although Oppenheim had first insisted that dystonia was an organic disease, it was only in the late-20th century that an organic framework was firmly established with the identification of genetic mutations in some families with dystonia and with the demonstration that the basal ganglia were often damaged contralateral to acquired hemidystonia. Focal and segmental forms of dystonia, including writer's cramp, other occupational dystonias, and torticollis, were also recognized in the 19th century. Writer's cramp was clearly described in the 1830s by Bell and Kopp, and increasingly recognized in the late 19th century due in part to Solly's influential lectures on "scriviner's palsy" in the 1860s, and to increasing prevalence because of the increase in writing using primitive writing instruments. Myoclonus: In 1903, Lundborg proposed a classification of myoclonus that remains in use, with primary (essential), epileptic, and secondary or symptomatic categories: essential myoclonus was described by Friedrich in 1881; forms of myoclonic epilepsy were described beginning in the late 19th century by West (1861), Unverricht (1891), and Lundberg (1903); and secondary multifocal myoclonus was recognized in a wide variety of disorders beginning in the 1920s. Asterixis was described in patients with hepatic encephalopathy by Adams and Foley in 1949 and found to result from electrically silent pauses in muscle activity, which led to the concept of negative myoclonus in the 1980s. Posthypoxic action myoclonus (Lance-Adams syndrome) was described by Lance and Adams in 1963 and found to incorporate both positive and negative components. Startle syndromes: Early descriptions of pathologic startle syndromes included Beard's description of the jumping Frenchmen of Maine (1878) and Hammond's description of miryachit (1884), both of which may have had psychological origins. In contrast, hyperekplexia or "startle disease" was described in the late 1950s and early 1960s, and genetic forms were later found to result from various mutations affecting glycinergic synapses. Tics: Tic disorders were described by Itard (1825) and Trousseau (1873), but only gained wider recognition in the late 19th century after Charcot presented cases before his classroom audiences and after Gilles de la Tourette's classic description in 1885. Gilles de la Tourette and Charcot initially considered tic disorders and startle syndromes to be similar if not identical, but these disorders were later recognized as distinct. Psychodynamic and psychological theories or etiology gave way in the 1960s to biological theories supporting an important role for dopamine in pathogenesis, particularly with the discovery that neuroleptic medications could be useful in treatment.

CONCLUSION

In the last two centuries, neuroscientists and clinicians contributed greatly to our understanding of basal ganglia anatomy and physiology, as well as to movement disorder semiology, pathophysiology, treatment, and prevention. The development of animal models, and the increasing use of genetic and molecular biological techniques will lead to further advances in the coming years.

Penicillamine and nephrotic syndrome

BACKGROUND

Penicillamine (PA) treatment may be associated with a wide spectrum of adverse effects. There are many case reports and small series of PA-induced nephrotic syndrome (NS). In addition to our patient, in this study, we review all the cases of NS due to PA treatment in the English literature.

METHODS

A retrospective Medline search was done for the years 1963-2004 using the terms "penicillamine" and "proteinuria" or "penicillamine" and "nephrotic". Cases were also located through article references. Cases were included in our review only if they had enough clinical and laboratory data and if the NS was considered by the authors to be mainly or solely due to PA treatment. Diagnosis of the patient, dose and duration of PA treatment, maximal amount of proteinuria, kidney function, urine analysis, serological markers, clinical data, kidney biopsy results, treatment, and course of proteinuria were documented.

RESULTS

Sixty-three patients met our criteria. The female/male ratio was 40:23. Seventy-five percent of the patients had rheumatoid arthritis (RA). Mean age at diagnosis of NS was 44 (+/-S.D. 14) years. Mean dose of PA at diagnosis was 1.09 (+/-S.D. 0.413) g. Mean duration of PA treatment prior to proteinuria was 7.6 (+/-S.D. 3.90) months and mean duration of PA treatment until diagnosis of NS was 11.9 (+/-S.D. 18.8) months. Peak level of proteinuria was 10.79 (+/-S.D. 9.436) g. Some 33% of the patients developed mild to moderate renal failure at the time of diagnosis of NS, and one patient developed acute renal failure. Fifty-five percent of the patients had membranous glomerulonephritis and 27% had minimal change disease. Twelve patients were treated with corticosteroids (CS) at a dose ranging from 40 to 90 mg/day. In the overwhelming majority of patients, the proteinuria decreased significantly or disappeared within 7 months after stopping PA treatment. Patients treated with CS had a faster response. Five patients died, two of them from the CS-treated group, due to sepsis.

CONCLUSION

The mean duration of PA treatment prior to the development of NS is nearly 1 year (5 months after the development of proteinuria). The most common histopathological finding is membranous glomerulonephritis. Most patients will have a significant reduction in, or disappearance of, proteinuria within 7 months after stopping PA treatment. The decrease in proteinuria is faster with CS treatment.

A family study of the biochemical defects in Wilson's disease

Estimations of serum copper, serum ceruloplasmin (immunochemical), and urinary amino-acids excretion (quantitative and chromatographic) in 44 healthy relatives of patients with Wilson's disease (39 from one family) are reported. Each technique revealed some abnormal individuals. Good agreement was obtained between the serum copper and serum ceruloplasmin estimations and between the quantitative and chromatographic estimations of amino-acid excretion. Some individuals were abnormal to one or other of the pairs of tests only. These results cast doubt on the hypothesis that the symptoms of Wilson's disease are secondary to a quantitative (or qualitative) abnormality of ceruloplasmin. They also suggest that the mode of inheritance of the biochemical defects may be more complicated than that of a simple recessive mutant gene. Two of the relatives (one pregnant and one immediately post-partum) had a high serum copper level, as is expected in pregnancy, but normal serum ceruloplasmin. This suggests that the mechanism of control of the serum ceruloplasmin concentration may, normally, depend on the serum copper concentration.

Wilson's Disease and Its Pharmacological Treatment

Wilson's disease is an inherited copper toxicosis caused by defective putative copper transporting ATPase in the liver. Because of impaired biliary secretion, copper remains in the liver, resulting in chronic hepatic lesions including fatty metamorphosis, chronic hepatitis and cirrhosis. In the latter stage, extrapyramidal syndromes may develop with and without symptomatic hepatic lesions. Acute liver damage associated with hemolysis and deep jaundice may be the first manifestation. The majority of patients show hypoceruloplasminemia, which has been used as a screening test for the disease. A large number of mutations in the ATP7B gene have been reported. Thus, genetic diagnosis might be limitedly used to presymptomatic diagnosis of siblings when mutations are identified in an index patient. Introduction of penicillamine caused a revolution in the treatment of patients. Another chelater, trientine, is now available for those intolerant of penicillamine. Tetrathiomolibdate and zinc acetate are additional alternatives currently being tested. Hypoceruloplasminemia and further reduction after chelation therapy may be associated with iron overload. This complication is closely related with impaired transport of ferrous ion due to ferroxidase deficiency. Noncompliance and teratogenicity are other major concerns because any treatment with the agents listed above is a life long regimen. Despite various side effects of penicillamine, its teratogenicity is negligible. These data indicate that penicillamine is the first choice of drug for this disease.

In vitro studies on the use of penicillamine with tartar emetic against Schistosoma mansoni worms

In vitro studies were carried out to test Sb125 tartar emetic (T.E.) in concentrations of 75, 100, 125, 150 and 200 mug/ml of rabbit serum and these concentrations together with penicillamine in ratios ranging from 1:1 to 1:6 for their effect on the motility and antimony uptake by Schistosoma mansoni worms. The motility was observed microscopically every half hour for six hours and the Sb125 content was measured by a scintillation counter at one hour intervals for five hours. Results indicate that the ratio in which penicillamine is used with T.E. is very important. The antimony uptake by the worm is reduced, and the onset of T.E. action is delayed when it is used with penicillamine in a ratio exceeding 1:2.

Orthotopic liver transplantation for Wilson's disease

An 11-year-old boy with terminal hepatic failure due to Wilson’s disease was treated 18 months ago with orthotopic liver transplantation. Postoperatively, there has been evidence of clearance of body copper stores but without accumulation of copper in biopsy specimens of the transplanted liver after 6 and 17 months. Further follow-up will be necessary before deciding whether the disorder has been cured by liver replacement and in turn whether this constitutes proof that Wilson’s disease is an inborn error of hepatic metabolism. The observations so far are consistent with these conclusions.

Clinical and pathological findings in a case of hepatolenticular degeneration treated with penicillamine

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