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Posts Tagged ‘autopsy’


Familial transthyretin amyloid polyneuropathy

Curator: Larry H. Bernstein, MD, FCAP

LPBI

 

First-Ever Evidence that Patisiran Reduces Pathogenic, Misfolded TTR Monomers and Oligomers in FAP Patients

We reported data from our ongoing Phase 2 open-label extension (OLE) study of patisiran, an investigational RNAi therapeutic targeting transthyretin (TTR) for the treatment of TTR-mediated amyloidosis (ATTR amyloidosis) patients with familial amyloidotic polyneuropathy (FAP). Alnylam scientists and collaborators from The Scripps Research Institute and Misfolding Diagnostics, Inc. were able to measure the effects of patisiran on pathogenic, misfolded TTR monomers and oligomers in FAP patients. Results showed a rapid and sustained reduction in serum non-native conformations of TTR (NNTTR) of approximately 90%. Since NNTTR is pathogenic in ATTR amyloidosis and the level of NNTTR reduction correlated with total TTR knockdown, these results provide direct mechanistic evidence supporting the therapeutic hypothesis that TTR knockdown has the potential to result in clinical benefit. Furthermore, complete 12-month data from all 27 patients that enrolled in the patisiran Phase 2 OLE study showed sustained mean maximum reductions in total serum TTR of 91% for over 18 months and a mean 3.1-point decrease in mNIS+7 at 12 months, which compares favorably to an estimated increase in mNIS+7 of 13 to 18 points at 12 months based upon analysis of historical data sets in untreated FAP patients with similar baseline characteristics. Importantly, patisiran administration continues to be generally well tolerated out to 21 months of treatment.

Read our press release

View the non-native TTR poster (480 KB PDF)

View the complete 12-month patisiran Phase 2 OLE data presentation (620 KB PDF)

We are encouraged by these new data that provide continued support for our hypothesis that patisiran has the potential to halt neuropathy progression in patients with FAP. If these results are replicated in a randomized, double-blind, placebo-controlled study, we believe that patisiran could emerge as an important treatment option for patients suffering from this debilitating, progressive and life-threatening disease.

 

Hereditary ATTR Amyloidosis with Polyneuropathy (hATTR-PN)

ATTR amyloidosis is a progressive, life-threatening disease caused by misfolded transthyretin (TTR) proteins that accumulate as amyloid fibrils in multiple organs, but primarily in the peripheral nerves and heart. ATTR amyloidosis can lead to significant morbidity, disability, and mortality. The TTR protein is produced primarily in the liver and is normally a carrier for retinol binding protein – one of the vehicles used to transport vitamin A around the body.  Mutations in the TTR gene cause misfolding of the protein and the formation of amyloid fibrils that typically contain both mutant and wild-type TTR that deposit in tissues such as the peripheral nerves and heart, resulting in intractable peripheral sensory neuropathy, autonomic neuropathy, and/or cardiomyopathy.

Click to Enlarge

 

ATTR represents a major unmet medical need with significant morbidity and mortality. There are over 100 reported TTR mutations; the particular TTR mutation and the site of amyloid deposition determine the clinical manifestations of the disease whether it is predominantly symptoms of neuropathy or cardiomyopathy.

Specifically, hereditary ATTR amyloidosis with polyneuropathy (hATTR-PN), also known as familial amyloidotic polyneuropathy (FAP), is an inherited, progressive disease leading to death within 5 to 15 years. It is due to a mutation in the transthyretin (TTR) gene, which causes misfolded TTR proteins to accumulate as amyloid fibrils predominantly in peripheral nerves and other organs. hATTR-PN can cause sensory, motor, and autonomic dysfunction, resulting in significant disability and death.

It is estimated that hATTR-PN, also known as FAP, affects approximately 10,000 people worldwide.  Patients have a life expectancy of 5 to 15 years from symptom onset, and the only treatment options for early stage disease are liver transplantation and TTR stabilizers such as tafamidis (approved in Europe) and diflunisal.  Unfortunately liver transplantation has limitations, including limited organ availability as well as substantial morbidity and mortality. Furthermore, transplantation eliminates the production of mutant TTR but does not affect wild-type TTR, which can further deposit after transplantation, leading to cardiomyopathy and worsening of neuropathy. There is a significant need for novel therapeutics to treat patients who have inherited mutations in the TTR gene.

Our ATTR program is the lead effort in our Genetic Medicine Strategic Therapeutic Area (STAr) product development and commercialization strategy, which is focused on advancing innovative RNAi therapeutics toward genetically defined targets for the treatment of rare diseases with high unmet medical need.  We are developing patisiran (ALN-TTR02), an intravenously administered RNAi therapeutic, to treat the hATTR-PN form of the disease.

Patisiran for the Treatment hATTR-PN

APOLLO Phase 3 Trial

In 2012, Alnylam entered into an exclusive alliance with Genzyme, a Sanofi company, to develop and commercialize RNAi therapeutics, including patisiran and revusiran, for the treatment of ATTR amyloidosis in Japan and the broader Asian-Pacific region. In early 2014, this relationship was extended as a significantly broader alliance to advance RNAi therapeutics as genetic medicines. Under this new agreement, Alnylam will lead development and commercialization of patisiran in North America and Europe while Genzyme will develop and commercialize the product in the rest of world.

 

Hereditary ATTR Amyloidosis with Cardiomyopathy (hATTR-CM)

ATTR amyloidosis is a progressive, life-threatening disease caused by misfolded transthyretin (TTR) proteins that accumulate as amyloid fibrils in multiple organs, but primarily in the peripheral nerves and heart. ATTR amyloidosis can lead to significant morbidity, disability, and mortality. The TTR protein is produced primarily in the liver and is normally a carrier for retinol binding protein – one of the vehicles used to transport vitamin A around the body.  Mutations in the TTR gene cause misfolding of the protein and the formation of amyloid fibrils that typically contain both mutant and wild-type TTR that deposit in tissues such as the peripheral nerves and heart, resulting in intractable peripheral sensory neuropathy, autonomic neuropathy, and/or cardiomyopathy.

Click to Enlarge                            http://www.alnylam.com/web/assets/tetramer.jpg

ATTR represents a major unmet medical need with significant morbidity and mortality. There are over 100 reported TTR mutations; the particular TTR mutation and the site of amyloid deposition determine the clinical manifestations of the disease, whether it is predominantly symptoms of neuropathy or cardiomyopathy.

Specifically, hereditary ATTR amyloidosis with cardiomyopathy (hATTR-CM), also known as familial amyloidotic cardiomyopathy (FAC), is an inherited, progressive disease leading to death within 2 to 5 years. It is due to a mutation in the transthyretin (TTR) gene, which causes misfolded TTR proteins to accumulate as amyloid fibrils primarily in the heart. Hereditary ATTR amyloidosis with cardiomyopathy can result in heart failure and death.

While the exact numbers are not known, it is estimated hATTR-CM, also known as FAC affects at least 40,000 people worldwide.  hATTR-CM is fatal within 2 to 5 years of diagnosis and treatment is currently limited to supportive care.  Wild-type ATTR amyloidosis (wtATTR amyloidosis), also known as senile systemic amyloidosis, is a nonhereditary, progressive disease leading to death within 2 to 5 years. It is caused by misfolded transthyretin (TTR) proteins that accumulate as amyloid fibrils in the heart. Wild-type ATTR amyloidosis can cause cardiomyopathy and result in heart failure and death. There are no approved therapies for the treatment of hATTR-CM or SSA; hence there is a significant unmet need for novel therapeutics to treat these patients.

Our ATTR program is the lead effort in our Genetic Medicine Strategic Therapeutic Area (STAr) product development and commercialization strategy, which is focused on advancing innovative RNAi therapeutics toward genetically defined targets for the treatment of rare diseases with high unmet medical need.  We are developing revusiran (ALN-TTRsc), a subcutaneously administered RNAi therapeutic for the treatment of hATTR-CM.

Revusiran for the Treatment of hATTR-CM

ENDEAVOUR Phase 3 Trial

In 2012, Alnylam entered into an exclusive alliance with Genzyme, a Sanofi company, to develop and commercialize RNAi therapeutics, including patisiran and revusiran, for the treatment of ATTR amyloidosis in Japan and the broader Asian-Pacific region. In early 2014, this relationship was extended as a broader alliance to advance RNAi therapeutics as genetic medicines. Under this new agreement, Alnylam and Genzyme have agreed to co-develop and co-commercialize revusiran in North America and Europe, with Genzyme developing and commercializing the product in the rest of world. This broadened relationship on revusiran is aimed at expanding and accelerating the product’s global value.

Pre-Clinical Data and Advancement of ALN-TTRsc02 for Transthyretin-Mediated Amyloidosis

We presented pre-clinical data with ALN-TTRsc02, an investigational RNAi therapeutic targeting transthyretin (TTR) for the treatment of TTR-mediated amyloidosis (ATTR amyloidosis).  In pre-clinical studies, including those in non-human primates (NHPs), ALN-TTRsc02 achieved potent and highly durable knockdown of serum TTR of up to 99% with multi-month durability achieved after just a single dose, supportive of a potentially once quarterly dose regimen. Results from studies comparing TTR knockdown activity of ALN-TTRsc02 to that of revusiran showed that ALN-TTRsc02 has a markedly superior TTR knockdown profile.  Further, in initial rat toxicology studies, ALN-TTRsc02 was found to be generally well tolerated with no significant adverse events at doses as high as 100 mg/kg.

Read our press release

View the presentation

http://www.alnylam.com/product-pipeline/hereditary-attr-amyloidosis-with-cardiomyopathy/

 

Emerging Therapies for Transthyretin Cardiac Amyloidosis Could Herald a New Era for the Treatment of HFPEF

Oct 14, 2015   |  Adam Castano, MDDavid Narotsky, MDMathew S. Maurer, MD, FACC

http://www.acc.org/latest-in-cardiology/articles/2015/10/13/08/35/emerging-therapies-for-transthyretin-cardiac-amyloidosis#sthash.9xzc0rIe.dpuf

Heart failure with a preserved ejection fraction (HFPEF) is a clinical syndrome that has no pharmacologic therapies approved for this use to date. In light of failed medicines, cardiologists have refocused treatment strategies based on the theory that HFPEF is a heterogeneous clinical syndrome with different etiologies. Classification of HFPEF according to etiologic subtype may, therefore, identify cohorts with treatable pathophysiologic mechanisms and may ultimately pave the way forward for developing meaningful HFPEF therapies.1

A wealth of data now indicates that amyloid infiltration is an important mechanism underlying HFPEF. Inherited mutations in transthyretin cardiac amyloidosis (ATTRm) or the aging process in wild-type disease (ATTRwt) cause destabilization of the transthyretin (TTR) protein into monomers or oligomers, which aggregate into amyloid fibrils. These insoluble fibrils accumulate in the myocardium and result in diastolic dysfunction, restrictive cardiomyopathy, and eventual congestive heart failure (Figure 1). In an autopsy study of HFPEF patients, almost 20% without antemortem suspicion of amyloid had left ventricular (LV) TTR amyloid deposition.2 Even more resounding evidence for the contribution of TTR amyloid to HFPEF was a study in which 120 hospitalized HFPEF patients with LV wall thickness ≥12 mm underwent technetium-99m 3,3-diphosphono-1,2-propranodicarboxylic acid (99mTc-DPD) cardiac imaging,3,4 a bone isotope known to have high sensitivity and specificity for diagnosing TTR cardiac amyloidosis.5,6 Moderate-to-severe myocardial uptake indicative of TTR cardiac amyloid deposition was detected in 13.3% of HFPEF patients who did not have TTR gene mutations. Therefore, TTR cardiac amyloid deposition, especially in older adults, is not rare, can be easily identified, and may contribute to the underlying pathophysiology of HFPEF.

Figure 1

As no U.S. Food and Drug Administration-approved drugs are currently available for the treatment of HFPEF or TTR cardiac amyloidosis, the development of medications that attenuate or prevent TTR-mediated organ toxicity has emerged as an important therapeutic goal. Over the past decade, a host of therapies and therapeutic drug classes have emerged in clinical trials (Table 1), and these may herald a new direction for treating HFPEF secondary to TTR amyloid.

Table 1

TTR Silencers (siRNA and Antisense Oligonucleotides)

siRNA

Ribonucleic acid interference (RNAi) has surfaced as an endogenous cellular mechanism for controlling gene expression. Small interfering RNAs (siRNAs) delivered into cells can disrupt the production of target proteins.7,8 A formulation of lipid nanoparticle and triantennary N-acetylgalactosamine (GalNAc) conjugate that delivers siRNAs to hepatocytes is currently in clinical trials.9 Prior research demonstrated these GalNAc-siRNA conjugates result in robust and durable knockdown of a variety of hepatocyte targets across multiple species and appear to be well suited for suppression of TTR gene expression and subsequent TTR protein production.

The TTR siRNA conjugated to GalNAc, ALN-TTRSc, is now under active investigation as a subcutaneous injection in phase 3 clinical trials in patients with TTR cardiac amyloidosis.10 Prior phase 2 results demonstrated that ALN-TTRSc was generally well tolerated in patients with significant TTR disease burden and that it reduced both wild-type and mutant TTR gene expression by a mean of 87%. Harnessing RNAi technology appears to hold great promise for treating patients with TTR cardiac amyloidosis. The ability of ALN-TTRSc to lower both wild-type and mutant proteins may provide a major advantage over liver transplantation, which affects the production of only mutant protein and is further limited by donor shortage, cost, and need for immunosuppression.

Antisense Oligonucleotides

Antisense oligonucleotides (ASOs) are under clinical investigation for their ability to inhibit hepatic expression of amyloidogenic TTR protein. Currently, the ASO compound, ISIS-TTRRx, is under investigation in a phase 3 multicenter, randomized, double-blind, placebo-controlled clinical trial in patients with familial amyloid polyneuropathy (FAP).11 The primary objective is to evaluate its efficacy as measured by change in neuropathy from baseline relative to placebo. Secondary measures will evaluate quality of life (QOL), modified body mass index (mBMI) by albumin, and pharmacodynamic effects on retinol binding protein. Exploratory objectives in a subset of patients with LV wall thickness ≥13 mm without a history of persistent hypertension will examine echocardiographic parameters, N-terminal pro–B-type natriuretic peptide (NT-proBNP), and polyneuropathy disability score relative to placebo. These data will facilitate analysis of the effect of antisense oligonucleotide-mediated TTR suppression on the TTR cardiac phenotype with a phase 3 trial anticipated to begin enrollment in 2016.

TTR Stabilizers (Diflunisal, Tafamidis)

Diflunisal

Several TTR-stabilizing agents are in various stages of clinical trials. Diflunisal, a traditionally used and generically available nonsteroidal anti-inflammatory drug (NSAID), binds and stabilizes familial TTR variants against acid-mediated fibril formation in vitro and is now in human clinical trials.12,13 The use of diflunisal in patients with TTR cardiac amyloidosis is controversial given complication of chronic inhibition of cyclooxygenase (COX) enzymes, including gastrointestinal bleeding, renal dysfunction, fluid retention, and hypertension that may precipitate or exacerbate heart failure in vulnerable individuals.14-17 In TTR cardiac amyloidosis, an open-label cohort study suggested that low-dose diflunisal with careful monitoring along with a prophylactic proton pump inhibitor could be safely administered to compensated patients.18 An association was observed, however, between chronic diflunisal use and adverse changes in renal function suggesting that advanced kidney disease may be prohibitive in diflunisal therapy.In FAP patients with peripheral or autonomic neuropathy randomized to diflunisal or placebo, diflunisal slowed progression of neurologic impairment and preserved QOL over two years of follow-up.19 Echocardiography demonstrated cardiac involvement in approximately 50% of patients.20 Longer-term safety and efficacy data over an average 38 ± 31 months in 40 Japanese patients with hereditary ATTR amyloidosis who were not candidates for liver transplantation showed that diflunisal was mostly well tolerated.12 The authors cautioned the need for attentive monitoring of renal function and blood cell counts. Larger multicenter collaborations are needed to determine diflunisal’s true efficacy in HFPEF patients with TTR cardiac amyloidosis.

Tafamidis

Tafamidis is under active investigation as a novel compound that binds to the thyroxine-binding sites of the TTR tetramer, inhibiting its dissociation into monomers and blocking the rate-limiting step in the TTR amyloidogenesis cascade.21 The TTR compound was shown in an 18-month double-blind, placebo-controlled trial to slow progression of neurologic symptoms in patients with early-stage ATTRm due to the V30M mutation.22 When focusing on cardiomyopathy in a phase 2, open-label trial, tafamidis also appeared to effectively stabilize TTR tetramers in non-V30M variants, wild-type and V122I, as well as biochemical and echocardiographic parameters.23,24 Preliminary data suggests that clinically stabilized patients had shorter disease duration, lower cardiac biomarkers, less myocardial thickening, and higher EF than those who were not stabilized, suggesting early institution of therapy may be beneficial. A phase 3 trial has completed enrollment and will evaluate the efficacy, safety, and tolerability of tafamidis 20 or 80 mg orally vs. placebo.25 This will contribute to long-term safety and efficacy data needed to determine the therapeutic effects of tafamidis among ATTRm variants.

Amyloid Degraders (Doxycycline/TUDCA and Anti-SAP Antibodies)

Doxycycline/TUDCA

While silencer and stabilizer drugs are aimed at lowering amyloidogenic precursor protein production, they cannot remove already deposited fibrils in an infiltrated heart. Removal of already deposited fibrils by amyloid degraders would be an important therapeutic strategy, particularly in older adults with heavily infiltrated hearts reflected by thick walls, HFPEF, systolic heart failure, and restrictive cardiomyopathy. Combined doxycycline and tauroursodeoxycholic acid (TUDCA) disrupt TTR amyloid fibrils and appeared to have an acceptable safety profile in a small phase 2 open-label study among 20 TTR patients. No serious adverse reactions or clinical progression of cardiac or neuropathic involvement was observed over one year.26 An active phase 2, single-center, open-label, 12-month study will assess primary outcome measures including mBMI, neurologic impairment score, and NT-proBNP.27 Another phase 2 study is examining the tolerability and efficacy of doxycycline/TUDCA over an 18-month period in patients with TTR amyloid cardiomyopathy.28 Additionally, a study in patients with TTR amyloidosis is ongoing to determine the effect of doxycycline alone on neurologic function, cardiac biomarkers, echocardiographic parameters, modified body mass index, and autonomic neuropathy.29

Anti-SAP Antibodies

In order to safely clear established amyloid deposits, the role of the normal, nonfibrillar plasma glycoprotein present in all human amyloid deposits, serum amyloid P component (SAP), needs to be more clearly understood.30 In mice with amyloid AA type deposits, administration of antihuman SAP antibody triggered a potent giant cell reaction that removed massive visceral amyloid deposits without adverse effects.31 In humans with TTR cardiac amyloidosis, anti-SAP antibody treatments could be feasible because the bis-D proline compound, CPHPC, is capable of clearing circulating human SAP, which allow anti-SAP antibodies to reach residual deposited SAP. In a small, open-label, single-dose-escalation, phase 1 trial involving 15 patients with systemic amyloidosis, none of whom had clinical evidence of cardiac amyloidosis, were treated with CPHPC followed by human monoclonal IgG1 anti-SAP antibody.32 No serious adverse events were reported and amyloid deposits were cleared from the liver, kidney, and lymph node. Anti-SAP antibodies hold promise as a potential amyloid therapy because of their potential to target all forms of amyloid deposits across multiple tissue types.

Mutant or wild-type TTR cardiac amyloidoses are increasingly recognized as a cause of HFPEF. Clinicians need to be aware of this important HFPEF etiology because the diverse array of emerging disease-modifying agents for TTR cardiac amyloidosis in human clinical trials has the potential to herald a new era for the treatment of HFPEF.

References

  1. Maurer MS, Mancini D. HFpEF: is splitting into distinct phenotypes by comorbidities the pathway forward? J Am Coll Cardiol 2014;64:550-2.
  2. Mohammed SF, Mirzoyev SA, Edwards WD, et al. Left ventricular amyloid deposition in patients with heart failure and preserved ejection fraction. JACC Heart Fail 2014;2:113-22.
  3. González-López E, Gallego-Delgado M, Guzzo-Merello G, et al. Wild-type transthyretin amyloidosis as a cause of heart failure with preserved ejection fraction. Eur Heart J 2015.
  4. Castano A, Bokhari S, Maurer MS. Unveiling wild-type transthyretin cardiac amyloidosis as a significant and potentially modifiable cause of heart failure with preserved ejection fraction. Eur Heart J 2015 Jul 28. [Epub ahead of print]
  5. Rapezzi C, Merlini G, Quarta CC, et al. Systemic cardiac amyloidoses: disease profiles and clinical courses of the 3 main types. Circulation 2009;120:1203-12.
  6. Bokhari S, Castano A, Pozniakoff T, Deslisle S, Latif F, Maurer MS. (99m)Tc-pyrophosphate scintigraphy for differentiating light-chain cardiac amyloidosis from the transthyretin-related familial and senile cardiac amyloidoses. Circ Cardiovasc Imaging 2013;6:195-201.
  7. Fire A, Xu S, Montgomery MK, Kostas SA, Driver SE, Mello CC. Potent and specific genetic interference by double-stranded RNA in Caenorhabditis elegans. Nature 1998;391:806-11.
  8. Elbashir SM, Harborth J, Lendeckel W, Yalcin A, Weber K, Tuschl T. Duplexes of 21-nucleotide RNAs mediate RNA interference in cultured mammalian cells. Nature 2001;411:494-8.
  9. Kanasty R, Dorkin JR, Vegas A, Anderson D. Delivery materials for siRNA therapeutics. Nature Mater 2013;12:967-77.
  10. U.S. National Institutes of Health. Phase 2 Study to Evaluate ALN-TTRSC in Patients With Transthyretin (TTR) Cardiac Amyloidosis (ClinicalTrials.gov website). 2014. Available at: https://www.clinicaltrials.gov/ct2/show/NCT01981837. Accessed 8/19/2015.
  11. U.S. National Institutes of Health. Efficacy and Safety of ISIS-TTRRx in Familial Amyloid Polyneuropathy (Clinical Trials.gov Website. 2013. Available at: http://www.clinicaltrials.gov/ct2/show/NCT01737398. Accessed 8/19/2015.
  12. Sekijima Y, Dendle MA, Kelly JW. Orally administered diflunisal stabilizes transthyretin against dissociation required for amyloidogenesis. Amyloid 2006;13:236-49.
  13. Tojo K, Sekijima Y, Kelly JW, Ikeda S. Diflunisal stabilizes familial amyloid polyneuropathy-associated transthyretin variant tetramers in serum against dissociation required for amyloidogenesis. Neurosci Res 2006;56:441-9.
  14. Epstein M. Non-steroidal anti-inflammatory drugs and the continuum of renal dysfunction. J Hypertens Suppl 2002;20:S17-23.
  15. Wallace JL. Pathogenesis of NSAID-induced gastroduodenal mucosal injury. Best Pract Res Clin Gastroenterol 2001;15:691-703.
  16. Mukherjee D, Nissen SE, Topol EJ. Risk of cardiovascular events associated with selective COX-2 inhibitors. JAMA 2001;286:954-9.
  17. Page J, Henry D. Consumption of NSAIDs and the development of congestive heart failure in elderly patients: an underrecognized public health problem. Arch Intern Med 2000;160:777-84.
  18. Castano A, Helmke S, Alvarez J, Delisle S, Maurer MS. Diflunisal for ATTR cardiac amyloidosis. Congest Heart Fail 2012;18:315-9.
  19. Berk JL, Suhr OB, Obici L, et al. Repurposing diflunisal for familial amyloid polyneuropathy: a randomized clinical trial. JAMA 2013;310:2658-67.
  20. Quarta CCF, Solomon RH Suhr SD, et al. The prevalence of cardiac amyloidosis in familial amyloidotic polyneuropathy with predominant neuropathy: The Diflunisal Trial. International Symposium on Amyloidosis 2014:88-9.
  21. 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 U S A 2002;99 Suppl 4:16427-32.
  22. Coelho T, Maia LF, Martins da Silva A, et al. Tafamidis for transthyretin familial amyloid polyneuropathy: a randomized, controlled trial. Neurology 2012;79:785-92.
  23. Merlini G, Plante-Bordeneuve V, Judge DP, et al. Effects of tafamidis on transthyretin stabilization and clinical outcomes in patients with non-Val30Met transthyretin amyloidosis. J Cardiovasc Transl Res 2013;6:1011-20.
  24. Maurer MS, Grogan DR, Judge DP, et al. Tafamidis in transthyretin amyloid cardiomyopathy: effects on transthyretin stabilization and clinical outcomes. Circ Heart Fail 2015;8:519-26.
  25. U.S. National Institutes of Health. Safety and Efficacy of Tafamidis in Patients With Transthyretin Cardiomyopathy (ATTR-ACT) (ClinicalTrials.gov website). 2014. Available at: http://www.clinicaltrials.gov/show/NCT01994889. Accessed 8/19/2015.
  26. Obici L, Cortese A, Lozza A, et al. Doxycycline plus tauroursodeoxycholic acid for transthyretin amyloidosis: a phase II study. Amyloid 2012;19 Suppl 1:34-6.
  27. U.S. National Institutes of Health. Safety, Efficacy and Pharmacokinetics of Doxycycline Plus Tauroursodeoxycholic Acid in Transthyretin Amyloidosis (ClinicalTrials.gov website). 2011. Available at: http://www.clinicaltrials.gov/ct2/show/NCT01171859. Accessed 8/19/2015.
  28. U.S. National Institutes of Health. Tolerability and Efficacy of a Combination of Doxycycline and TUDCA in Patients With Transthyretin Amyloid Cardiomyopathy (ClinicalTrials.gov website). 2013. Available at: http://www.clinicaltrials.gov/ct2/show/NCT01855360. Accessed 8/19/2015.
  29. U.S. National Institutes of Health. Safety and Effect of Doxycycline in Patients With Amyloidosis (ClinicalTrials.gov website).2015. Available at: https://clinicaltrials.gov/ct2/show/NCT01677286. Accessed 8/19/2015.
  30. Pepys MB, Dash AC. Isolation of amyloid P component (protein AP) from normal serum as a calcium-dependent binding protein. Lancet 1977;1:1029-31.
  31. Bodin K, Ellmerich S, Kahan MC, et al. Antibodies to human serum amyloid P component eliminate visceral amyloid deposits. Nature 2010;468:93-7.
  32. Richards DB, Cookson LM, Berges AC, et al. Therapeutic Clearance of Amyloid by Antibodies to Serum Amyloid P Component. N Engl J Med 2015;373:1106-14.

 

The Acid-Mediated Denaturation Pathway of Transthyretin Yields a Conformational Intermediate That Can Self-Assemble into Amyloid

Zhihong Lai , Wilfredo Colón , and Jeffery W. Kelly *
Department of Chemistry, Texas A&M University, College Station, Texas 77843-3255
Biochemistry199635 (20), pp 6470–6482   http://dx.doi.org:/10.1021/bi952501g
Publication Date (Web): May 21, 1996  Copyright © 1996 American Chemical Society

Transthyretin (TTR) amyloid fibril formation is observed during partial acid denaturation and while refolding acid-denatured TTR, implying that amyloid fibril formation results from the self-assembly of a conformational intermediate. The acid denaturation pathway of TTR has been studied in detail herein employing a variety of biophysical methods to characterize the intermediate(s) capable of amyloid fibril formation. At physiological concentrations, tetrameric TTR remains associated from pH 7 to pH 5 and is incapable of amyloid fibril formation. Tetrameric TTR dissociates to a monomer in a process that is dependent on both pH and protein concentration below pH 5. The extent of amyloid fibril formation correlates with the concentration of the TTR monomer having an altered, but defined, tertiary structure over the pH range of 5.0−3.9. The inherent Trp fluorescence-monitored denaturation curve of TTR exhibits a plateau over the pH range where amyloid fibril formation is observed (albeit at a higher concentration), implying that a steady-state concentration of the amyloidogenic intermediate with an altered tertiary structure is being detected. Interestingly, 1-anilino-8-naphthalenesulfonate fluorescence is at a minimum at the pH associated with maximal amyloid fibril formation (pH 4.4), implying that the amyloidogenic intermediate does not have a high extent of hydrophobic surface area exposed, consistent with a defined tertiary structure. Transthyretin has two Trp residues in its primary structure, Trp-41 and Trp-79, which are conveniently located far apart in the tertiary structure of TTR. Replacement of each Trp with Phe affords two single Trp containing variants which were used to probe local pH-dependent tertiary structural changes proximal to these chromophores. The pH-dependent fluorescence behavior of the Trp-79-Phe mutant strongly suggests that Trp-41 is located near the site of the tertiary structural rearrangement that occurs in the formation of the monomeric amyloidogenic intermediate, likely involving the C-strand−loop−D-strand region. Upon further acidification of TTR (below pH 4.4), the structurally defined monomeric amyloidogenic intermediate begins to adopt alternative conformations that are not amyloidogenic, ultimately forming an A-state conformation below pH 3 which is also not amyloidogenic. In summary, analytical equilibrium ultracentrifugation, SDS−PAGE, far- and near-UV CD, fluorescence, and light scattering studies suggest that the amyloidogenic intermediate is a monomeric predominantly β-sheet structure having a well-defined tertiary structure.

 

Prevention of Transthyretin Amyloid Disease by Changing Protein Misfolding Energetics

Per Hammarström*, R. Luke Wiseman*, Evan T. Powers, Jeffery W. Kelly   + Author Affiliations

Science  31 Jan 2003; 299(5607):713-716   http://dx.doi.org:/10.1126/science.1079589

Genetic evidence suggests that inhibition of amyloid fibril formation by small molecules should be effective against amyloid diseases. Known amyloid inhibitors appear to function by shifting the aggregation equilibrium away from the amyloid state. Here, we describe a series of transthyretin amyloidosis inhibitors that functioned by increasing the kinetic barrier associated with misfolding, preventing amyloidogenesis by stabilizing the native state. The trans-suppressor mutation, threonine 119 → methionine 119, which is known to ameliorate familial amyloid disease, also functioned through kinetic stabilization, implying that this small-molecule strategy should be effective in treating amyloid diseases.

 

Rational design of potent human transthyretin amyloid disease inhibitors

Thomas Klabunde1,2, H. Michael Petrassi3, Vibha B. Oza3, Prakash Raman3, Jeffery W. Kelly3 & James C. Sacchettini1

Nature Structural & Molecular Biology 2000; 7: 312 – 321.                http://dx.doi.org:/10.1038/74082

The human amyloid disorders, familial amyloid polyneuropathy, familial amyloid cardiomyopathy and senile systemic amyloidosis, are caused by insoluble transthyretin (TTR) fibrils, which deposit in the peripheral nerves and heart tissue. Several nonsteroidal anti-inflammatory drugs and structurally similar compounds have been found to strongly inhibit the formation of TTR amyloid fibrils in vitro. These include flufenamic acid, diclofenac, flurbiprofen, and resveratrol. Crystal structures of the protein–drug complexes have been determined to allow detailed analyses of the protein–drug interactions that stabilize the native tetrameric conformation of TTR and inhibit the formation of amyloidogenic TTR. Using a structure-based drug design approach ortho-trifluormethylphenyl anthranilic acid and N-(meta-trifluoromethylphenyl) phenoxazine 4,6-dicarboxylic acid have been discovered to be very potent and specific TTR fibril formation inhibitors. This research provides a rationale for a chemotherapeutic approach for the treatment of TTR-associated amyloid diseases.

 

First European consensus for diagnosis, management, and treatment of transthyretin familial amyloid polyneuropathy

Adams, Davida; Suhr, Ole B.b; Hund, Ernstc; Obici, Laurad; Tournev, Ivailoe,f; Campistol, Josep M.g; Slama, Michel S.h; Hazenberg, Bouke P.i; Coelho, Teresaj; from the European Network for TTR-FAP (ATTReuNET)

Current Opin Neurol: Feb 2016; 29 – Issue – p S14–S26      http://dx.doi.org:/10.1097/WCO.0000000000000289

Purpose of review: Early and accurate diagnosis of transthyretin familial amyloid polyneuropathy (TTR-FAP) represents one of the major challenges faced by physicians when caring for patients with idiopathic progressive neuropathy. There is little consensus in diagnostic and management approaches across Europe.

Recent findings: The low prevalence of TTR-FAP across Europe and the high variation in both genotype and phenotypic expression of the disease means that recognizing symptoms can be difficult outside of a specialized diagnostic environment. The resulting delay in diagnosis and the possibility of misdiagnosis can misguide clinical decision-making and negatively impact subsequent treatment approaches and outcomes.

Summary: This review summarizes the findings from two meetings of the European Network for TTR-FAP (ATTReuNET). This is an emerging group comprising representatives from 10 European countries with expertise in the diagnosis and management of TTR-FAP, including nine National Reference Centres. The current review presents management strategies and a consensus on the gold standard for diagnosis of TTR-FAP as well as a structured approach to ongoing multidisciplinary care for the patient. Greater communication, not just between members of an individual patient’s treatment team, but also between regional and national centres of expertise, is the key to the effective management of TTR-FAP.

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Transthyretin familial amyloid polyneuropathy (TTR-FAP) is a highly debilitating and irreversible neurological disorder presenting symptoms of progressive sensorimotor and autonomic neuropathy [1▪,2▪,3]. TTR-FAP is caused by misfolding of the transthyretin (TTR) protein leading to protein aggregation and the formation of amyloid fibrils and, ultimately, to amyloidosis (commonly in the peripheral and autonomic nervous system and the heart) [4,5]. TTR-FAP usually proves fatal within 7–12 years from the onset of symptoms, most often due to cardiac dysfunction, infection, or cachexia [6,7▪▪].

The prevalence and disease presentation of TTR-FAP vary widely within Europe. In endemic regions (northern Portugal, Sweden, Cyprus, and Majorca), patients tend to present with a distinct genotype in large concentrations, predominantly a Val30Met substitution in the TTR gene [8–10]. In other areas of Europe, the genetic footprint of TTR-FAP is more varied, with less typical phenotypic expression [6,11]. For these sporadic or scattered cases, a lack of awareness among physicians of variable clinical features and limited access to diagnostic tools (i.e., pathological studies and genetic screening) can contribute to high rates of misdiagnosis and poorer patient outcomes [1▪,11]. In general, early and late-onset variants of TTR-FAP, found within endemic and nonendemic regions, present several additional diagnostic challenges [11,12,13▪,14].

Delay in the time to diagnosis is a major obstacle to the optimal management of TTR-FAP. With the exception of those with a clearly diagnosed familial history of FAP, patients still invariably wait several years between the emergence of first clinical signs and accurate diagnosis [6,11,14]. The timely initiation of appropriate treatment is particularly pertinent, given the rapidity and irreversibility with which TTR-FAP can progress if left unchecked, as well as the limited effectiveness of available treatments during the later stages of the disease [14]. This review aims to consolidate the existing literature and present an update of the best practices in the management of TTR-FAP in Europe. A summary of the methods used to achieve a TTR-FAP diagnosis is presented, as well as a review of available treatments and recommendations for treatment according to disease status.

Patients with TTR-FAP can present with a range of symptoms [11], and care should be taken to acquire a thorough clinical history of the patient as well as a family history of genetic disease. Delay in diagnosis is most pronounced in areas where TTR-FAP is not endemic or when there is no positive family history [1▪]. TTR-FAP and TTR-familial amyloid cardiomyopathy (TTR-FAC) are the two prototypic clinical disease manifestations of a broader disease spectrum caused by an underlying hereditary ATTR amyloidosis [19]. In TTR-FAP, the disease manifestation of neuropathy is most prominent and definitive for diagnosis, whereas cardiomyopathy often suggests TTR-FAC. However, this distinction is often superficial because cardiomyopathy, autonomic neuropathy, vitreous opacities, kidney disease, and meningeal involvement all may be present with varying severity for each patient with TTR-FAP.

Among early onset TTR-FAP with usually positive family history, symptoms of polyneuropathy present early in the disease process and usually predominate throughout the progression of the disease, making neurological testing an important diagnostic aid [14]. Careful clinical examination (e.g., electromyography with nerve conduction studies and sympathetic skin response, quantitative sensation test, quantitative autonomic test) can be used to detect, characterize, and scale the severity of neuropathic abnormalities involving small and large nerve fibres [10]. Although a patient cannot be diagnosed definitively with TTR-FAP on the basis of clinical presentation alone, symptoms suggesting the early signs of peripheral neuropathy, autonomic dysfunction, and cardiac conduction disorders or infiltrative cardiomyopathy are all indicators that further TTR-FAP diagnostic investigation is warranted. Late-onset TTR-FAP often presents as sporadic cases with distinct clinical features (e.g., milder autonomic dysfunction) and can be more difficult to diagnose than early-onset TTR-FAP (Table 2) [1▪,11,12,13▪,14,20].

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Genetic testing is carried out to allow detection of specific amyloidogenic TTR mutations (Table 1), using varied techniques depending on the expertise and facilities available in each country (Table S2, http://links.lww.com/CONR/A39). A targeted approach to detect a specific mutation can be used for cases belonging to families with previous diagnosis. In index cases of either endemic and nonendemic regions that do not have a family history of disease, are difficult to confirm, and have atypical symptoms, TTR gene sequencing is required for the detection of both predicted and new amyloidogenic mutations [26,27].

Following diagnosis, the neuropathy stage and systemic extension of the disease should be determined in order to guide the next course of treatment (Table 4) [3,30,31]. The three stages of TTR-FAP severity are graded according to a patient’s walking disability and degree of assistance required [30]. Systemic assessment, especially of the heart, eyes, and kidney, is also essential to ensure all aspects of potential impact of the disease can be detected [10].

Table 4

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Image Tools

The goals of cardiac investigations are to detect serious conduction disorders with the risk of sudden death and infiltrative cardiomyopathy. Electrocardiograms (ECG), Holter-ECG, and intracardiac electrophysiology study are helpful to detect conduction disorders. Echocardiograms, cardiac magnetic resonance imaging, scintigraphy with bone tracers, and biomarkers (e.g., brain natriuretic peptide, troponin) can all help to diagnose infiltrative cardiomyopathy[10]. An early detection of cardiac abnormalities has obvious benefits to the patient, given that the prophylactic implantation of pacemakers was found to prevent 25% of major cardiac events in TTR-FAP patients followed up over an average of 4 years [32▪▪]. Assessment of cardiac denervation with 123-iodine meta-iodobenzylguanidine is a powerful prognostic marker in patients diagnosed with FAP [33].

…..

Tafamidis

Tafamidis is a first-in-class therapy that slows the progression of TTR amyloidogenesis by stabilizing the mutant TTR tetramer, thereby preventing its dissociation into monomers and amyloidogenic and toxic intermediates [55,56]. Tafamidis is currently indicated in Europe for the treatment of TTR amyloidosis in adult patients with stage I symptomatic polyneuropathy to delay peripheral neurological impairment [57].

In an 18-month, double-blind, placebo-controlled study of patients with early-onset Val30Met TTR-FAP, tafamidis was associated with a 52% lower reduction in neurological deterioration (P = 0.027), a preservation of nerve function, and TTR stabilization versus placebo [58▪▪]. However, only numerical differences were found for the coprimary endpoints of neuropathy impairment [neuropathy impairment score in the lower limb (NIS-LL) responder rates of 45.3% tafamidis vs 29.5% placebo; P = 0.068] and quality of life scores [58▪▪]. A 12-month, open-label extension study showed that the reduced rates of neurological deterioration associated with tafamidis were sustained over 30 months, with earlier initiation of tafamidis linking to better patient outcomes (P = 0.0435) [59▪]. The disease-slowing effects of tafamidis may be dependent on the early initiation of treatment. In an open-label study with Val30Met TTR-FAP patients with late-onset and advanced disease (NIS-LL score >10, mean age 56.4 years), NIS-LL and disability scores showed disease progression despite 12 months of treatment with tafamidis, marked by a worsening of neuropathy stage in 20% and the onset of orthostatic hypotension in 22% of patients at follow-up [60▪].

Tafamidis is not only effective in patients exhibiting the Val30Met mutation; it also has proven efficacy, in terms of TTR stabilization, in non-Val30Met patients over 12 months [61]. Although tafamidis has demonstrated safe use in patients with TTR-FAP, care should be exercised when prescribing to those with existing digestive problems (e.g., diarrhoea, faecal incontinence) [60▪].

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Diflunisal

Diflunisal is a nonsteroidal anti-inflammatory drug (NSAID) that, similar to tafamidis, slows the rate of amyloidogenesis by preventing the dissociation, misfolding, and misassembly of the mutated TTR tetramer [62,63]. Off-label use has been reported for patients with stage I and II disease, although diflunisal is not currently licensed for the treatment of TTR-FAP.

Evidence for the clinical effectiveness of diflunisal in TTR-FAP derives from a placebo-controlled, double-blind, 24-month study in 130 patients with clinically detectable peripheral or autonomic neuropathy[64▪]. The deterioration in NIS scores was significantly more pronounced in patients receiving placebo compared with those taking diflunisal (P = 0.001), and physical quality of life measures showed significant improvement among diflunisal-treated patients (P = 0.001). Notable during this study was the high rate of attrition in the placebo group, with 50% more placebo-treated patients dropping out of this 2-year study as a result of disease progression, advanced stage of the disease, and varied mutations.

One retrospective analysis of off-label use of diflunisal in patients with TTR-FAP reported treatment discontinuation in 57% of patients because of adverse events that were largely gastrointestinal [65]. Conclusions on the safety of diflunisal in TTR-FAP will depend on further investigations on the impact of known cardiovascular and renal side-effects associated with the NSAID drug class [66,67].

 

 

 

 

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Topics in Pathology

Larry H Bernstein, MD, FCAP, Curator

LPBI

Special Issues from Medscape Pathology

Journal of Clinical Pathology

Hospital Autopsy: Endangered or Extinct?

Angus Turnbull; Michael Osborn; Nick Nicholas

Disclosures

J Clin Pathol. 2015;68(8):601-604.

Abstract

Aim To determine the hospital autopsy rate for the UK in 2013.

Methods A study of data from a ‘Freedom of Information’ request to all (n=186) acute NHS Trusts within England (n=160), NHS Boards in Scotland (n=14) and Wales (n=7) and Social Care Trusts in Northern Ireland (n=5). Hospital autopsy rates were calculated from the number of hospital autopsies performed in 2013 as a percentage of total inpatient deaths in the Trust that year.

Results The UK response rate was 99% (n=184), yielding a mean autopsy rate of 0.69%. The mean rates were 0.51% (England), 2.13% (Scotland), 0.65% (Wales) and 0.46% (Northern Ireland). 23% (n=38) of all included respondents had a rate of 0% and 86% (n=143) a rate less than 1%.

Conclusions The decline in hospital autopsy has continued relentlessly and, for better or for worse, the practice is on the verge of extinction in the UK. The study highlights to health professionals and policy makers the magnitude of this decline. Further research should investigate the impact of this on patient safety, clinical audit, public health and medical education.

Introduction

Autopsy from the Greek ‘autos’ and ‘opsomeri’ means ‘to see for oneself’.[1,2] Its history stems from mummification and human dissection in 3000 BC, through ancient Greece where Hirophilus discovered the duodenum by live human dissection to Rokitansky (1804–1878), regarded as the father of the modern autopsy and who performed or supervised over 100 000 examinations.[1]

Autopsies in the UK comprise medicolegal (those required by HM coroner or in Scotland the procurator fiscal) and hospital consent (clinical) autopsies. Many doctors believe that autopsy is outdated while some argue that autopsies should remain an integral part of medicine, education, clinical audit and research.[1]

In 2013, 45% of registered deaths in England and Wales were reported to the coroner. Of these, 41% underwent coronial autopsy, accounting for approximately 20% of all deaths and over 94 000 autopsies.[3]

Hospital autopsy rates have been falling in the UK and worldwide for over half a century[4–15] (figure 1A, B) and account for a small minority of all autopsies in the UK.[1,3] Recent studies suggest autopsy rates of less than 10% for teaching hospitals and less than 5% elsewhere.[1,16]

Decline in hospital autopsy rates

Decline in hospital autopsy rates

Figure 1.

Decline in hospital autopsy rates over recent decades. (A) Autopsy rates from three first world countries, data collated from multiple studies. (B) Autopsy rates from four different hospitals/NHS Trusts, data collated from multiple studies.

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The decline in hospital autopsy rates is well known, yet poorly researched and quantified. The majority of medical professionals and politicians in the UK are likely to be unaware of this conspicuous decline. Consequently, little has been done to address the falling rates and the implications of this are not yet fully understood, nor are the consequences.

A PubMed literature search yielded no research detailing a UK-wide autopsy rate within the past 20 years (search terms “hospital autopsy [title]”, “clinical autopsy [title]”, “autopsy rate [title]”). Given this and documented inter-hospital variation (figure 1B), we aimed to determine the current UK autopsy rate.

The structure of healthcare delivery varies throughout the UK. In England, the provision of acute services (emergency, inpatient and outpatient care) is provided by 186 organisations known as Acute National Health Service (NHS) Trusts—each of which may provide care from multiple hospital sites. In Scotland and Wales, the countries are divided into a number of defined geographical areas (Boards), each of which may contain several sites of healthcare delivery. In Northern Ireland, these geographical areas are known as Health and Social Care Trusts.

Method

Acute NHS Trusts within England (n=160), Boards within Wales (n=7) and Scotland (n=14) and Social Care Trusts within Northern Ireland (n=5) were contacted via ‘Freedom of Information’ requests. The level of response therefore is for the Trust/Board, not individual hospitals. If no reply was received within 4 months, reminders were sent.

The hospital autopsy rate was calculated as the number of autopsies performed on patients who died in the year 2013 as a percentage of total deaths which occurred in the hospital in that calendar year.

Studies indicate significantly higher autopsy rates in stillbirths, neonates and young children.[17,18]Therefore, data were excluded if they fell within the following categories:

  1. Children’s Hospital NHS Trusts
  2. Stillbirth, neonatal, perinatal and paediatric death
  3. Trusts with no recorded deaths
  4. Incomplete responses

Statistical analysis was performed using two-tailed χ2 tests (Prism 6 Software) between each country. The categories used were number of deaths that underwent autopsy and number of deaths not followed by autopsy. Bonferroni correction was used to compensate for the six pairwise comparisons, resulting in 99.25 CIs (p<0.008). Statistical outliers were determined with a ROUT test using a false-positive rate (Q) of 1%.

Results

A 99% (n=184) response rate was achieved for the UK; constituent country response rates were 99% (England), 100% (Scotland), 100% (Wales) and 100% (Northern Ireland). A total of 17 Trusts were removed, according to the exclusion criteria. Eight Trusts were concerned about patient identification because the number of autopsies was small and so provided a ‘fewer than’ figure. In these cases, a maximum possible rate was calculated.

Mean hospital autopsy rates were calculated as the total number of autopsies expressed as a percentage of the total number of deaths. The UK mean autopsy rate was 0.69% and varied considerably between countries. The highest mean autopsy rates were in Scotland (2.1%), followed by Wales (0.65%), England (0.51%) and Northern Ireland (0.46%). The study confirms that hospital autopsy rates are significantly lower than the most recent literature suggests and that there is evident inter-country variation (figure 2A, Table 1) and intra-country variation (figure 2A).

Figure 2.

The results from Freedom of Information request for UK and constituent countries. (A) Individual points representing each sample Trust/Board, non-parametric data, no statistical difference between countries. (B) Cumulative frequency histogram of autopsy rates for NHS Trusts/Boards in the UK.

autopsy rates

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Inter-country pairwise comparisons using χ2 tests of significance (p<0.008) found Scotland to have a significantly higher hospital autopsy rate than each of the other countries (p<0.0001). Other pairwise comparisons failed to achieve significance (Table 2).

Twenty eight samples were statistical high outliers, 20 from England, 6 from Scotland, 1 from Wales and 1 from Northern Ireland. The mean hospital autopsy rate is skewed by these outliers, which typically were large teaching hospitals or small specialist centres. The top 5% (n=7) of Trusts within England performed 47% of the country’s autopsies and 75% of autopsies in Wales were performed in one health board.

Ninety-eight per cent of samples (n=164) had an autopsy rate of <5%, 86% (n=143) an autopsy rate <1% and 23% (n=38) of all samples did not perform a single autopsy in 2013 (figure 2B). This demonstrates that for a quarter of NHS Trusts/Boards in the UK, hospital autopsy is extinct and in only a fraction (1.8%) of specialist trusts do autopsy rates exceed 5%, the rate previously published for non-teaching hospitals.[1,18]

Hospital autopsy rates in children’s hospital NHS Trusts ranged from 0% to 21%. This higher figure is in agreement with other literature.[17,18]

Discussion

This study has demonstrated that the evident decline in hospital autopsy has continued, if not accelerated, over recent years and already the hospital autopsy is extinct in many NHS Trusts. With 23% of NHS Trusts/Boards having an autopsy rate of 0%, a large part of UK hospital autopsy is now performed in a small number of centres. These few demonstrate that if the provisions and attitudes allow, then hospital autopsy rates of the recent past are still achievable, despite recent legislative changes such as the Human Tissue Act 2004/2006. Trusts with higher autopsy rates tended to be small specialised centres or large teaching hospital Trusts; this influence was not measured in this study due to difficulties in defining a ‘teaching’ or ‘specialised’ Trust/Board. Given that 86% of Trusts/Boards in the UK now have a hospital autopsy rate of <1%, we must pose the question whether a revival in hospital autopsy is possible? In the near future, many of these organisations may join the 23% in which hospital autopsy is extinct, unless they implement those changes in policy and attitude present in the 1.8% of Trusts/Boards where hospital autopsy exceeds 5% of inpatient deaths?

The hospital autopsy rate in Scotland was significantly higher than the other countries (Table 2). The causes of this are uncertain but may include variations in the Human Tissue Act and Authority in Scotland or a lower procurator fiscal (coronial) autopsy rate.

A number of Trusts/Boards gave some explanations as to why their autopsy rate was low, these commonly surrounded provision of facilities. For example, one Trust does not employ an onsite histopathologist or have its own autopsy facilities. However, some Trusts/Boards which themselves do not have onsite hospital autopsy facilities have an agreement with neighbouring Trusts/Boards to carry out their autopsies. From the results, there is evidence of remote island providers that continue to implement autopsy despite no local facilities but which transport cadavers via boat or aeroplane to a separate hospital for autopsy. Thus, a lack of facilities does not preclude hospital autopsy although may add significantly to the cost.

Future research should investigate the differences in Trust/Board policies, clinician attitudes, facilities, funding and local demographics to determine how significantly higher autopsy rates can be achieved.

The strength of this study lies in the nationwide approach to calculating contemporary hospital autopsy rates. Previous studies have focused on single hospitals or Trusts; given the demonstrated wide inter-Trust variation this approach may lead to significant errors. A weakness of this study was that some hospital trusts were unable to separate the data for deaths and autopsies for children and adults. Therefore, mean adult autopsy rates may be slightly over-reported, rates being generally higher among paediatric deaths.

In England and Wales, 94 455 coronial autopsies were performed in 2013[3] yet only 1132 hospital autopsies were performed within the English and Welsh Trusts included in this study. Hospital autopsy now accounts for approximately 1.2% of total autopsies. With such low numbers, questions must be raised regarding the effect such decline has on quality assurance, public health, misdiagnosis (a key contributor to avoidable harm[19,20]), audit and the teaching of both medical students and trainee pathologists. Hospital autopsy presents classic cases used to train junior pathologists, given that many coronial postmortems are not used for training. Training in hospital autopsy will become ever more important given the impending lack of pathologists to cover coronial autopsy. The aim of this paper is to raise awareness of the extent of the decline and to prompt discussion on its consequences. While debate continues over the value of hospital autopsy in medical practice, if action is not taken imminently, the practice may disappear.

COMMENTARY

Prostate Cancer: Is It Time to Retire the Gleason Score?

George D. Lundberg, MD

Hello. I am Dr George Lundberg and this is At Large at Medscape.

If you are an American adult male, you either now have prostate cancer—whether or not you know it—or will likely develop it if you live long enough.

In an average recent year, some 220,000 American men are diagnosed with prostate cancer and some 27,000 die from it. That means, obviously, that it kills 12% of those it is found to afflict and does not kill 88%. Of those patients freshly diagnosed, 98.9% are alive at 5 years.

Does interventional therapy account for the good results of some of that nearly 90% of men who are diagnosed and don’t die? Well, yes, but probably not very many. Really bad prostate cancer tends to do its lethal thing, regardless of interventions.

Back when we collectively had a lot of autopsies, it was possible—even easy—- to follow and learn the natural history of many diseases.

Modern autopsy-less American physicians, including pathologists, are whizz-bang at computers, imaging, lab test panels, genes, microbiomes, electronic medical records, and coding. They are maybe not so great at physical exams, taking a useful personal and family history, or gross and microscopic pathology. This latter list is where physicians once got really good at understanding the natural history of diseases.

Now, epidemiologic facts, outcomes, and common sense have begun to prevail over the national hysteria of prostate-specific antigen (PSA) tests for all men. The hysteria tends to take this form: “Find that prostate cancer and root it out…no matter how small or indolent. That way, ‘Megalopolis U’ can keep those operating rooms, hospital beds, and—get this—unproven (but very elegant) proton beameconomic monstrosities really humming in order to satisfy the overpaid MBAs that determined that such were a good investment idea.”

But some prostate cancers really can kill. How about those? A pathologist named Donald Gleason came up with a numbering system intended to guide therapy based upon anaplasia and prognostic threat of prostate cancer. It was 1, 2, 3, 4, and 5. It makes sense. But then, another number dealing with the relative amount of each level of differentiation and pattern (also 1, 2, 3, 4, 5) got added, and combining the two scores became the Gleason score range of 2-10.

A reasonable human could interpret a 6 on a scale of 10 as middling, pretty bad, or a “better-whack-it-out”-type score. So, a team from Johns Hopkins Medical Institutions[1] has worked out the actual prognosis as falling back into 5 Prognostic Grade Groups (PGGs):

  • Gleason 1, 2, 3, 4, 5, and 6 become Prognostic Grade Group (PGG I);
  • Gleason 3 + 4 = 7 (PGG II);
  • Gleason 4 + 3 = 7 (PGG III);
  • Gleason 4 + 4 = 8 (PGG IV); and
  • Gleason 9-10 (PGG V).

This is so much simpler and less likely to confuse the treating clinician and the patient who is increasingly sharing in this treatment decision.

A European group has just published outcomes based on this PGG system,[2] and it fits nicely. Those many patients with low grades who may not need radical therapy will stand a better chance of notreceiving radical therapy with new low-sounding numbers.

And, by the way, how did “watchful waiting” as a good way to handle those prostate “cancers”—which, from histology, seem like they would behave as indolentomas—morph so quickly into “active surveillance”? My guess is that it is very hard to bill a patient, Medicare, or an insurance company for just letting the patient watch and wait.

Chicago Mayor Rahm—not his physician brother Zeke—Emanuel was right: Never let a crisis go to waste. When the word “cancer” was uttered or written, hair lit on fire and something had to be done, right or wrong.

That is my opinion. I’m Dr George Lundberg.

Medscape Medical News Conference News

New Clue as to Why Only Some Breast Cancers Relapse

Zosia Chustecka

UPDATED September 26, 2015 // VIENNA — A new clue as to why only some breast cancers recur comes from the largest study of genetic sequencing of breast cancer tissue to date.

While most breast cancer is cured after treatment, about 20% of cases recur. The new study shows that the cases that recur have a different genetic profile, and suggests that some of the genetic drivers of relapse are targetable with drugs.

“We demonstrate that there are clear differences within the driver landscapes of relapsed cancers. This probably reflects a combination of predisposition to relapse and of differences in the mutations acquired during the relapse and metastasis phase,” say the researchers, led by Lucy Yates, MD, a clinical research oncologist from the Wellcome Trust Sanger Institute in Cambridge, United Kingdom.

The finding raises the hope that breast cancer patients who are most at risk for relapse can be identified when they are first diagnosed, they suggest.

In addition, as the newly identified genetic drivers of relapse are targetable with drugs, there is also hope that eventually women who are identified as being at high risk for relapse could be treated with such drugs to prevent recurrence, they suggest.

The study is due to be presented European Cancer Congress (ECC) 2015, but details were released early by the ECC press office.

The finding comes from a study that compared the genetic make-up of breast cancer from 836 tissue samples taken from women on primary diagnosis with 161 samples of tissue taken from recurrences or metastases.

The study is the largest and most comprehensive carried out to date, say the researchers, both in terms of the number of samples from relapsed breast cancers and in terms of the wide-ranging genetic sequencing carried out, which looked at 365 genes involved in cancer-related pathways.

The researchers performed de novo driver mutation discovery, and individual mutations were annotated with likely driver status based upon recurrence and known driver status in previously published, well-curated datasets and databases. The incidence of each driver mutation in the primary and relapse datasets was compared using Fisher’s exact test and using the Benjamini–Hochberg correction for multiple testing.

The team found 11 genes that were significantly enriched in the relapsed cohort compared with the primary tumor cohort. The most heavily enriched were TP53 and ARID1B. Multiple samples were available for 66 patients, including local or distant relapse samples in all cases and a sample from the primary tumor in 21 cases. This multisample analysis allowed the team to trace the evolution of mutations.

“We have found that some of the genetic mutations that drive breast cancers that relapse are relatively uncommon amongst cancers that do not relapse at the point of primary diagnosis,” Dr Yates said in a statement.

“We believe that the differences we have seen reflect genetic differences that can predispose a cancer to return, combined with mutations acquired throughout the period from first diagnosis to the subsequent relapse,” she added.

However, in a discussion of this paper, Fabrice André, MD, PhD, from the Gustave Roussy Institute, in Villejuif, France, questioned whether all the genes that were found to be enriched in the relapsed samples were driving the relapse and whether any could be identified as recurrent markers. He noted that although Dr Yates and colleagues found 11 genes that were highly enriched in the relapsed tissue samples, another study (which analyzed 183 samples) found only one of these genes to be highly enriched.

Dr Andre also wondered whether the late mutations that were identified are clinically relevant ― could they explain the development of resistance to therapy? This has been seen in other cancers, he noted.

Extreme Heterogeneity ― Need for Multiple Biopsies

“Our data reveal extreme heterogeneity and indicate that genomic analysis of primary, relapsed, and matched normal tissue are needed,” Dr Yates concluded.

“We need to do biopsies again and again and again,” said Anne-Lise Borresen-Dale, MD, from the Institute for Cancer Research, Oslo University Hospital, Norway, who chaired the session. But Dr Andre wondered whether circulating tumor cells, the so-called “liquid biopsy,” could be used.

Multiple samples were available for 66 subjects, including local or distant relapse samples in all cases and a sample from the primary tumor in 21 cases. This multisample analysis permitted relative temporal ordering of driver mutation accumulation to be determined, the researchers explain.

“We have found that some of the genetic mutations that drive breast cancers that relapse are relatively uncommon amongst cancers that do not relapse at the point of primary diagnosis,” Dr Yates said in a statement.

“This study highlights the differences between genetic alterations that drive relapsed and metastatic disease as opposed to primary breast cancers, and underlines the importance of analyzing the genetic features of metastases when making treatment decisions,” said Jorge Reis-Filho, MD, from the Memorial Sloan Kettering Cancer Center in New York City, who was acting as a spokesperson for the European Society of Medical Oncology, which is cohosting the meeting. He was not involved with this work.

However, Dr Reis-Filho also cautioned that “the extent of the differences in the repertoire of mutations among different metastatic sites within individual patients remains to be determined, however, as does the best way to obtain tumor-derived genetic material in patients with metastatic disease. We also need to know more about whether single or multiple metastatic sites should be analyzed in this context.”

Also commenting on the study, Peter Naredi, MD, PhD, professor of surgery at Sahlgrenska University Hospital in Gothenburg, Sweden, who is the European CanCer Organization scientific cochair of the congress, said: “Information such as that which Dr Yates will present is very important in the era of precision medicine.”

“This study also underlines the fact that we should consider a recurrence of a cancer as a new event, and carefully select the right treatment for the recurrent tumor as opposed to just relying on information from the first occurrence,” Dr Naredi said in a statement.

JAK Inhibitors in Breast Cancer

Some of the genetic changes that were found in the relapsed/metastatic breast cancer samples appeared at a late stage when the cancer recurred, and were not seen in samples taken at primary diagnosis. Among these later-stage mutations, the researchers say they found “compelling evidence” for the tumor suppression activity of two related genes, called JAK2 and STAT3, that operate within the same signaling pathway.

“Within some breast cancers, a disruption in this signaling pathway seems to be advantageous for survival of the cancer,” Dr Yates said in a statement.

“Interestingly, this is in contrast to the role of JAK2 in some other cancers, where overactivity of the gene drives malignancy rather than suppresses it,” she added.

The JAK (Janus-associated kinase) enzymes JAK1 and JAK2 are involved in regulating blood and immunologic functioning, and a dysregulation of these enzymes is thought to be a driver in the development of myelofibrosis. The first JAK inhibitor, ruxolitinib (Jakafi, Incyte Corp), was approved for the treatment of myelofibrosis in 2011.

Dr Yates and colleagues note that enhanced JAK-STAT signaling is known to play an important role in breast cancer stem cell development and cancerous cell line survival, and preclinical evidence seems to suggest that inhibiting the gene would be therapeutically advantageous. These findings have led to the development of clinical trials for breast cancer using JAK inhibitors in the hope that they will slow cancer progression.

“However, our findings suggest that, in a subset of cancers, inhibiting this pathway may have the opposite effect, and this requires further investigation. In general, the observation highlights the importance of understanding the diverse nature of breast cancers in the era of precision medicine,” Dr Yates said.

The work was funded by the Wellcome Trust. Dr Yates has disclosed no relevant financial relationships.

European Cancer Congress (ECC) 2015: Abstract 1804.

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