Inotersen for the treatment of adults with polyneuropathy caused by hereditary transthyretin-mediated amyloidosis

Introduction: Hereditary transthyretin-mediated amyloidosis (ATTRv; v for variant) is an underdiagnosed, progressive, and fatal multisystemic disease with a heterogenous clinical phenotype that is caused by TTR gene mutations that destabilize the TTR protein, resulting in its misfolding, aggregation, and deposition in tissues throughout the body. Areas covered: Inotersen, an antisense oligonucleotide inhibitor, was recently approved in the United States and Europe for the treatment of the polyneuropathy of ATTRv based on the positive results obtained in the pivotal phase 3 trial, NEURO-TTR. This review will discuss the mechanism of action of inotersen and its pharmacology, clinical efficacy, and safety and tolerability. A PubMed search using the terms 'inotersen,' 'AG10,' 'antisense oligonucleotide,' 'hereditary transthyretin amyloidosis,' 'familial amyloid polyneuropathy,' and 'familial amyloid cardiomyopathy' was performed, and the results were screened for the most relevant English language publications. The bibliographies of all retrieved articles were manually searched to identify additional studies of relevance. Expert opinion: Inotersen targets the disease-forming protein, TTR, and has been shown to improve quality of life and neuropathy progression in patients with stage 1 or 2 ATTRv with polyneuropathy. Inotersen is well tolerated, with a manageable safety profile through regular monitoring for the development of glomerulonephritis or thrombocytopenia

Inotersen preserves or improves quality of life in hereditary transthyretin amyloidosis

Objective: To examine the impact on quality of life (QOL) of patients with hATTR amyloidosis with polyneuropathy treated with inotersen (Tegsedi™) versus placebo. Methods: Data were from the NEURO-TTR trial (ClinicalTrials.gov Identifier: NCT01737398), a phase 3, multinational, randomized, double-blind, placebo-controlled study of inotersen in patients with hATTR amyloidosis with polyneuropathy. At baseline and week 66, QOL measures-the Norfolk-QOL-Diabetic Neuropathy (DN) questionnaire and SF-36v2® Health Survey (SF-36v2)-were assessed. Treatment differences in mean changes in QOL from baseline to week 66 were tested using mixed-effect models with repeated measures. Responder analyses compared the percentages of patients whose QOL meaningfully improved or worsened from baseline to week 66 in inotersen and placebo arms. Descriptive analysis of item responses examined treatment differences in specific activities and functions at week 66. Results: Statistically significant mean differences between treatment arms were observed for three of five Norfolk-QOL-DN domains and five of eight SF-36v2 domains, with better outcomes for inotersen than placebo in physical functioning, activities of daily living, neuropathic symptoms, pain, role limitations due to health problems, and social functioning. A larger percentage of patients in the inotersen arm than the placebo arm showed preservation or improvement in Norfolk-QOL-DN and SF-36v2 scores from baseline to week 66. Responses at week 66 showed more substantial problems with daily activities and functioning for patients in the placebo arm than in the inotersen arm. Conclusion: Patients with hATTR amyloidosis with polyneuropathy treated with inotersen showed preserved or improved QOL at 66 weeks compared to those who received placebo.This research was funded by Akcea Therapeutics and Ionis Pharmaceuticals, Incinfo:eu-repo/semantics/publishedVersio

Design and Rationale of the Global Phase 3 NEURO-TTRansform Study of Antisense Oligonucleotide AKCEA-TTR-LRx (ION-682884-CS3) in Hereditary Transthyretin-Mediated Amyloid Polyneuropathy

Introduction: AKCEA-TTR-LRx is a ligand-conjugated antisense (LICA) drug in development for the treatment of hereditary transthyretin amyloidosis (hATTR), a fatal disease caused by mutations in the transthyretin (TTR) gene. AKCEA-TTR-LRx shares the same nucleotide sequence as inotersen, an antisense medicine approved for use in hATTR polyneuropathy (hATTR-PN). Unlike inotersen, AKCEA-TTR-LRx is conjugated to a triantennary N-acetylgalactosamine moiety that supports receptor-mediated uptake by hepatocytes, the primary source of circulating TTR. This advanced design increases drug potency to allow for lower and less frequent dosing. The NEURO-TTRansform study will investigate whether AKCEA-TTR-LRx is safe and efficacious, with the aim of improving neurologic function and quality of life in hATTR-PN patients. Methods/design: Approximately 140 adults with stage 1 (independent ambulation) or 2 (requires ambulatory support) hATTR-PN are anticipated to enroll in this multicenter, open-label, randomized, phase 3 study. Patients will be assigned 6:1 to AKCEA-TTR-LRx 45 mg subcutaneously every 4 weeks or inotersen 300 mg once weekly until the prespecified week 35 interim efficacy analysis, after which patients receiving inotersen will receive AKCEA-TTR-LRx 45 mg subcutaneously every 4 weeks. All patients will then receive AKCEA-TTR-LRx through the remainder of the study treatment period. The final efficacy analysis at week 66 will compare the AKCEA-TTR-LRx arm with the historical placebo arm from the phase 3 trial of inotersen (NEURO-TTR). The primary outcome measures are between-group differences in the change from baseline in serum TTR, modified Neuropathy Impairment Score + 7, and Norfolk Quality of Life-Diabetic Neuropathy questionnaire. Conclusion: NEURO-TTRansform is designed to determine whether targeted delivery of AKCEA-TTR-LRx to hepatocytes with lower and less frequent doses will translate into clinical and quality-of-life benefits for patients with hATTR-PN

Vision Loss In Chronic Inflammatory Demyelinating Polyradiculoneuropathy: A Case Series

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an acquired, immune-mediated, and clinically heterogeneous disease affecting the nerve roots and peripheral nerves. CIDP classically presents with gradually progressive and often proximal limb weakness and numbness accompanied by areflexia, elevated cerebrospinal fluid (CSF) protein without pleocytosis, and electrodiagnostic or pathologic evidence of demyelination. We report three cases where vision loss was an early and prominent symptom in new onset CIDP: two cases of papilledema, and one case of optic neuropathy

Neuropathy symptom and change: Inotersen treatment of hereditary transthyretin amyloidosis

Introduction: Hereditary transthyretin-mediated amyloidosis (hATTR) manifests as multisystem dysfunction, including progressive polyneuropathy. Inotersen, an antisense oligonucleotide, improved the course of neuropathic impairment in patients with hATTR in the pivotal NEURO-TTR study (NCT01737398). To determine inotersen's impact on symptoms and patients' neuropathy experience, we performed a post hoc analysis of the Neuropathy Symptoms and Change (NSC) score. Methods: Stage 1 or 2 hATTR patients were randomized to receive weekly subcutaneous inotersen or placebo for 65 weeks. NSC score was assessed at baseline and 35 and 66 weeks. Results: At 66 weeks, inotersen-treated patients had symptom stabilization as compared with worsening in patients receiving placebo, based on total NSC score. There were also improvements in the subdomains of muscle weakness, sensory, pain, and autonomic symptoms, and for various individual items. Discussion: Inotersen treatment stabilized neuropathy symptoms, including autonomic symptoms, in patients with hATTR according to NSC score. Thus, the NSC may be an effective measure to assess neuropathy progression and patients' neuropathy experience in clinical practice.info:eu-repo/semantics/publishedVersio

Precision targeting of autoantigen-specific B cells in muscle-specific tyrosine kinase myasthenia gravis with chimeric autoantibody receptor T cells.

Muscle-specific tyrosine kinase myasthenia gravis (MuSK MG) is an autoimmune disease that causes life-threatening muscle weakness due to anti-MuSK autoantibodies that disrupt neuromuscular junction signaling. To avoid chronic immunosuppression from current therapies, we engineered T cells to express a MuSK chimeric autoantibody receptor with CD137-CD3ζ signaling domains (MuSK-CAART) for precision targeting of B cells expressing anti-MuSK autoantibodies. MuSK-CAART demonstrated similar efficacy as anti-CD19 chimeric antigen receptor T cells for depletion of anti-MuSK B cells and retained cytolytic activity in the presence of soluble anti-MuSK antibodies. In an experimental autoimmune MG mouse model, MuSK-CAART reduced anti-MuSK IgG without decreasing B cells or total IgG levels, reflecting MuSK-specific B cell depletion. Specific off-target interactions of MuSK-CAART were not identified in vivo, in primary human cell screens or by high-throughput human membrane proteome array. These data contributed to an investigational new drug application and phase 1 clinical study design for MuSK-CAART for the treatment of MuSK autoantibody-positive MG

Characteristics of Patients with Hereditary Transthyretin Amyloidosis-Polyneuropathy (ATTRv-PN) in NEURO-TTRansform, an Open-label Phase 3 Study of Eplontersen

Introduction: Hereditary transthyretin (ATTRv) amyloidosis is a rare, severe, progressive, debilitating, and ultimately fatal disease caused by systemic deposition of transthyretin (TTR) amyloid fibrils. ATTRv amyloidosis occurs in both males and females. Eplontersen (ION-682884), a ligand-conjugated antisense oligonucleotide designed to degrade hepatic TTR mRNA, is being evaluated for the treatment of ATTRv amyloidosis with polyneuropathy (ATTRv-PN) in the phase 3, international, multicenter, open-label NEURO-TTRansform study (NCT04136184). To describe the study population of this pivotal trial, here we report the baseline characteristics of patients enrolled in the NEURO-TTRansform study. Methods: Patients eligible for NEURO-TTRansform were 18–82 years old with a diagnosis of ATTRv-PN and Coutinho stage 1 (ambulatory without assistance) or stage 2 (ambulatory with assistance) disease; documented TTR gene variant; signs and symptoms consistent with neuropathy associated with ATTRv; no prior liver transplant; and New York Heart Association (NYHA) functional class I or II. Results: The NEURO-TTRansform study enrolled 168 patients across 15 countries/territories (North America, 15.5%; Europe, 38.1%; South America/Australia/Asia, 46.4%). At baseline, the study cohort had a mean age of 52.8 years, 69.0% of patients were male, and 78.0% of patients were White. The V30M variant was most prevalent (60.1% of patients), and prevalence varied by region. Overall, 56.5% and 17.3% of patients had received previous treatment with tafamidis or diflunisal, respectively. A majority of patients (79.2%) had Coutinho stage 1 disease (unimpaired ambulation) and early (before age 50) disease onset (53.0%). Time from diagnosis to enrollment was 46.6 (57.4) months (mean [standard deviation]). Most patients had a baseline polyneuropathy disability (PND) score of I (40.5%) or II (41.1%), and the mean modified Neuropathy Impairment Score + 7 (mNIS + 7) was 79.0. Conclusion: The recruited population in the ongoing NEURO-TTRansform study has global representation characteristic of contemporary clinical practice.

ATTR amyloidosis during the COVID-19 pandemic: insights from a global medical roundtable

The global spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection causing the ongoing coronavirus disease 2019 (COVID-19) pandemic has raised serious concern for patients with chronic disease. A correlation has been identified between the severity of COVID-19 and a patient's preexisting comorbidities. Although COVID-19 primarily involves the respiratory system, dysfunction in multiple organ systems is common, particularly in the cardiovascular, gastrointestinal, immune, renal, and nervous systems. Patients with amyloid transthyretin (ATTR) amyloidosis represent a population particularly vulnerable to COVID-19 morbidity due to the multisystem nature of ATTR amyloidosis