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Plain Language Summary: What is this summary about? This summary describes results from The Transthyretin Amyloidosis Outcomes Survey (THAOS for short). THAOS is a real-world study of people with a heart condition called transthyretin amyloid cardiomyopathy (ATTR-CM for short). Researchers looked at how tafamidis affects people with ATTR-CM who had both heart- and nerve-related symptoms. They calculated how long people lived and compared the data between those who took tafamidis and those who did not. They also compared how long and how often people had to stay in the hospital. Lastly, researchers looked at the side effects that people had during the study when they took tafamidis.

What are the key takeaways? After two and a half years, a larger proportion of people who took tafamidis (82% or 82 in 100) were estimated to be alive than people who did not take tafamidis (75% or 75 in 100). On average, people who took tafamidis were hospitalized for heart-related problems less often than people who did not take tafamidis. People who took tafamidis also had shorter hospital stays for heart-related problems. The side effects people had when taking tafamidis were similar to those reported in previous clinical studies.

What were the main conclusions reported by the researchers? The results from this real-world study suggest that people with ATTR-CM with heart- and nerve-related symptoms who take tafamidis may live longer with less frequent and shorter hospital stays for heart-related symptoms.

Clinical trial number: NCT00628745.

Background: Central Nervous System involvement in hereditary transthyretin amyloidosis (ATTRv) is present in liver transplanted patients with longstanding ATTRV30M amyloidosis, and in some rarer variants. The pathophysiology of brain involvement and its relationship with cognitive disturbances is unknown. This systematic review summarized the literature on brain and cognitive involvement in ATTRv amyloidosis and aimed to elucidate the reasons for such involvement.

Methods: The literature search was performed using the following databases: Medline/PubMed, Embase via Elsevier, Scopus, and Web of Science. Two assessors independently screened titles and abstracts, examined full texts, extracted data, and assessed the risk of bias. The risk of bias assessment was carried out using the JBI critical appraisal tools. This review included studies that applied any neuroimaging exam or cognitive assessment in humans with genetic confirmation of any TTR mutation.

Results: 59 studies met the inclusion criteria. Overall, the studies were of good quality. 57 studies reported at least one brain MRI technique. Only six studies reported a formal neuropsychological assessment. The studies included 1218 ATTRv patients (mean 45.7 ± 11.8 years) and 169 asymptomatic TTR variant carriers (mean 30.6 ± 7.5 years). The most common TTR variant was V30M (n = 936), followed by V122I (n = 74). 42.4% of ATTRv patients presented abnormalities in the neuroimaging exam and 19.7% presented cognitive dysfunction.

Conclusion: Based on the available evidence, brain involvement and cognitive symptoms can be present in ATTRv amyloidosis. Further research should explore the relationship of these symptoms with other complications (autonomic and cardiologic).

Background: The NEURO-TTRansform trial showed that after 66 weeks of treatment, eplontersen significantly reduced neuropathic impairment and improved quality of life (QoL) in patients with hereditary transthyretin-mediated amyloidosis with polyneuropathy (ATTRv-PN). In this secondary analysis from NEURO-TTRansform, autonomic impairment, and the impact of eplontersen on autonomic impairment progression was evaluated through 85 weeks in patients randomised to eplontersen (n = 144) versus external placebo (n = 60; through Week 66 from the NEURO-TTR trial).

Methods: Change from baseline in modified Neuropathy Impairment Score +7 (mNIS+7) composite score, Norfolk Quality of Life-Diabetic Neuropathy (Norfolk QoL-DN) total score, and the Neuropathy Symptoms and Change (NSC) total score was evaluated. Exploratory assessments were change in autonomic components of these instruments, Composite Autonomic Symptom Score-31 (COMPASS-31) total score, and nutritional status (modified body mass index [mBMI]).

Results: Patients reported profound autonomic dysfunction at baseline. Improvements with eplontersen versus placebo were observed up to Week 66 in autonomic components of mNIS+7, Norfolk QoL-DN, NSC, and mBMI; eplontersen results were sustained up to Week 85, including improvements in COMPASS-31 (Week 81).

Conclusions: Eplontersen demonstrated benefit across multiple measures of autonomic impairment known to progress rapidly and negatively impact QoL without treatment, without deterioration in nutritional status.

Introduction/Aims: The degree of change in neuropathic impairment and quality of life (QoL) that is clinically meaningful to patients with hereditary transthyretin amyloidosis with polyneuropathy (ATTRv-PN) is not established. This study aimed to estimate the magnitude of treatment differences that are meaningful to patients in measures of neuropathy and QoL and to determine whether eplontersen achieved a meaningful improvement versus placebo.

Methods: Data from the NEURO-TTRansform trial on patients with ATTRv-PN treated with eplontersen (n = 141) or historical placebo (n = 59) were used. Anchor-based approaches were used to estimate thresholds for meaningful differences in the modified Neuropathy Impairment Score +7 (mNIS+7) composite score, Norfolk QoL-Diabetic Neuropathy (Norfolk QoL-DN) total score, Neuropathy Symptoms and Change (NSC) total score, and modified body mass index (mBMI). Differences between the least squares means of the treatment groups were analyzed.

Results: Meaningful improvement in mNIS+7 was estimated as −4.0 points and deterioration as 1.8 points. The estimated ranges of meaningful improvement and deterioration in Norfolk QoL-DN were −12.8 to −4.0 points, and 5.9 to 14.7 points, respectively. For NSC, ranges were −2.4 to −1.3 points for meaningful improvement, and 0.6 to 5.8 points for deterioration. The estimated meaningful improvement in mBMI was 9.8 kg/m2 × g/L and deterioration was −40.9 kg/m2 × g/L. Improvements in each measure with eplontersen versus placebo were greater than the estimates of meaningful differences.

Discussion: Eplontersen demonstrated a clinically meaningful effect on neuropathic impairment, QoL, and nutritional status. Such estimates have implications for clinical practice and trials.

Background: Central nervous system symptoms, such as cognitive dysfunction, have been reported in Hereditary Transthyretin Amyloidosis (ATTRv). However, there is a lack of neuroimaging studies investigating structural alterations in the brain related to cognition in ATTRv amyloidosis. This study aimed to investigate cognition and cortical morphology in a cohort of ATTRv patients.

Methods: 29 ATTRv patients and 26 healthy controls completed neuropsychological assessment. 21 of these patients underwent 3T brain MRI, and 23 healthy subjects constituted the control group for MRI. Cortical measures of volume, thickness, fractional anisotropy (FA), and mean diffusivity (MD) were obtained for both groups. Correlation analyses between brain and cognitive measurements were performed.

Results: Patients displayed worse performance than controls in executive functions, verbal and visual memory, visuospatial domains, and language tests. Our study indicated cortical thinning in ATTRv patients in the temporal, occipital, frontal, and parietal areas. The inferior temporal gyrus correlated with verbal memory. Insula and, pars opercularis correlated with both verbal memory and executive function.

Conclusions: Cortical thickness in the inferior temporal gyrus, pars opercularis, and insula were linked to memory and executive function. We observed no correlations between cortical volume measures and cognition. Further investigations are imperative to confirm these findings across different populations.

Importance: There is a lack of long-term efficacy and safety data on hereditary transthyretin amyloidosis with polyneuropathy (hATTR-PN) and on RNA interference (RNAi) therapeutics in general. This study presents the longest-term data to date on patisiran for hATTR-PN.

Objective: To present the long-term efficacy and safety of patisiran in adults with hATTR-PN.

Design, Setting, and Participants: This global open-label extension (OLE) of the APOLLO randomized clinical trial and phase 2 OLE study enrolled patients from 43 hospitals or clinical centers across 19 countries between July 2015 and August 2017, with follow-up until November 2022. Of 212 eligible patients with hATTR who completed the phase 3 APOLLO or phase 2 OLE parent studies, 211 enrolled in and 138 completed the global OLE.

Intervention: Patisiran, 0.3 mg/kg, intravenously once every 3 weeks for up to 5 years.

Main Outcomes and Measures: Outcomes evaluated at year 5 of the global OLE included disability (polyneuropathy disability [PND] score); polyneuropathy severity (Neuropathy Impairment Score [NIS]), nutritional status (modified body mass index [mBMI]), quality of life (Norfolk Quality of Life-Diabetic Neuropathy [Norfolk QOL-DN]), and Rasch-Built Overall Disability Scale (R-ODS), with no statistical hierarchy. Safety, survival probability, and mortality were also assessed.

Results: At the global OLE baseline, the mean (SD) age was 61.3 (12.3) years, and 156 patients (73.9%) were male. In 138 patients completing the study, PND scores remained stable or improved in 89 patients (65.0%), NISs showed a mean (SD) change of 10.9 (14.7), and mean (SD) mBMI (calculated as weight in kilograms divided by height in meters squared times serum albumin in grams per liter) increased by 46.4 (120.7) over 5 years from baseline. Norfolk QOL-DN and R-ODS scores showed mean (SD) changes of 4.1 (16.7) and -3.7 (6.2), respectively. Adverse events (AEs) leading to study withdrawal occurred in 47 patients (22.3%). Infusion-related reactions were the most common treatment-related AE (n = 34 [16.1%]). Overall, 41 patients (19.4%) died during the study. Patisiran treatment in the parent study and low familial amyloid polyneuropathy score at parent study baseline were associated with significantly improved survival.

Conclusions and Relevance: In the longest study of an RNAi therapeutic for any disease, patisiran treatment resulted in modest changes for patients with hATTR-PN with an acceptable safety profile. These results highlight the importance of initiating early treatment for hATTR and the potential of RNAi therapeutics in medicine. Trial

Registration: ClinicalTrials.gov Identifier: NCT02510261.

Background: Hereditary transthyretin (ATTRv) amyloidosis is a rare but life-threatening multisystemic disease. Multiple disease-modifying treatments are now available and standardised instruments for early detection and disease monitoring are essential. Still, validated and easy-to-use tools for clinical follow-up are scarce.

Methods: The Kumamoto scale was first described in 1997 as a method for systematically evaluating patients with ATTRv amyloidosis and has been used in clinical trials since. A panel of amyloidosis experts from Sweden, Denmark, and Norway discussed the strengths and limitations of the Kumamoto scale at the Nordic Amyloidosis Day at Arlanda in 2023, and it was decided to revise and improve the scale that has been used in routine clinical monitoring of patients in Sweden since 2020. Our aim is to introduce the revised version of the Kumamoto scale as a useful clinical monitoring tool.

Results: Minor adjustments were applied to make the scale more sensitive and precise. Bedside instruments for sensory examination were defined as well as the sensory and motor levels. Constipation was added as a sign of autonomic dysfunction. The subtotal and total scores remain unchanged.

Conclusions: We believe that the revised Kumamoto scale is a reliable and easy-to-use clinical tool for monitoring ATTRv amyloidosis.

Background: Hereditary transthyretin (ATTRv) amyloidosis was first described in Sweden in the late 1960s. Selected patient data have been collected since then and have now been transferred to a national quality registry.

Methods: This is the first report from SveATTR—a longitudinal Swedish web-based registry open for TTR variant carriers and patients with ATTR amyloidosis. The registry covers basic background information, as well as relevant clinical follow-up measures and data on disease-modifying therapies. Data from all ATTRv amyloidosis patients registered through December 2022 were included.

Results: In total, 1055 patients were included, of whom 65% were males and 95% carried the V30M variant. Median age of onset was 64 years, and 79% had a late disease onset (≥50 years). Eighty-seven percent of the patients had peripheral polyneuropathy at onset, whereas 10% had cardiac symptoms, 8% had visual disturbances, and 6% had gastrointestinal symptoms. A total of 159 patients had undergone liver transplantation, and 233 had received a disease-modifying drug. Improved survival was seen for transplanted patients and for patients on drug therapy.

Conclusion: This report highlights the importance of SveATTR for further characterization of the Swedish ATTRv amyloidosis population as well as for evaluating the efficacy of disease-modifying therapies.

Introduction: Tafamidis is approved to treat transthyretin amyloid cardiomyopathy (ATTR-CM). Many patients with ATTR-CM present with a mixed phenotype of both cardiac and neurologic symptoms, but real-world effectiveness studies of tafamidis in this population are lacking. This study assessed survival and other outcomes in a real-world, contemporary cohort of tafamidis-treated and untreated patients with mixed-phenotype ATTR-CM.

Methods: The Transthyretin Amyloidosis Outcomes Survey (THAOS) was a longitudinal, observational, phase 4 study of patients with transthyretin amyloidosis and asymptomatic carriers of pathogenic transthyretin gene variants and was completed in June 2023. This analysis included a contemporary cohort of patients enrolled in THAOS in 2019-2023 who were characterized as having mixed-phenotype ATTR-CM at enrollment. The tafamidis-treated cohort received the approved dose of tafamidis (meglumine 80 mg/free acid 61 mg) throughout the study, and the untreated cohort never received tafamidis.

Results: In tafamidis-treated (n = 116) and untreated patients (n = 223), respectively, median age at enrollment was 77.8 and 72.8 years, and 42.2% and 77.6% had variant ATTR-CM. Survival rates at 30 months were 81.5% (95% CI 66.7-90.2) in tafamidis-treated patients and 75.1% (95% CI 66.1-82.0) in untreated patients. Median yearly incidence of cardiovascular-related hospitalizations was 0.89 for tafamidis-treated and 1.70 for untreated patients, and median duration of cardiovascular-related hospitalizations was 7.0 and 11.5 days, respectively. There were 13 (11.2%) and 40 (17.9%) deaths in the respective groups.

Conclusion: Patients with mixed-phenotype ATTR-CM treated with the approved dose of tafamidis had numerically higher survival rates, a numerically lower rate of cardiovascular-related hospitalizations, and fewer deaths than untreated patients. These data parallel recent results for patients with predominantly cardiac ATTR-CM from THAOS and extend results of ATTR-ACT to a contemporary, real-world, mixed-phenotype population.

Trial Registration: ClinicalTrials.gov identifier NCT00628745