Vutrisiran Improves Survival and Reduces Cardiovascular Events in ATTR Amyloid Cardiomyopathy: HELIOS-B

Background: Patients with transthyretin amyloidosis with cardiomyopathy (ATTR-CM) have high mortality and morbidity. Vutrisiran, a subcutaneous RNA interference therapeutic, reduced the composite of all-cause mortality (ACM) and cardiovascular (CV) events (CV hospitalizations and urgent heart failure [HF] visits) in HELIOS-B (A Study to Evaluate Vutrisiran in Patients With Transthyretin Amyloidosis With Cardiomyopathy) in patients with ATTR-CM. Objectives: Here we present data from HELIOS-B evaluating the impact of vutrisiran on ACM and CV mortality with additional patient follow-up through 42 months, and CV events such as CV hospitalizations, HF hospitalizations, and urgent HF visits. Methods: The HELIOS-B trial randomized 655 patients to vutrisiran 25 mg or placebo once every 3 months for up to 33 to 36 months in the double-blind (DB) period, followed by an open-label extension. Prespecified mortality and CV mortality analyses used data through 39 to 42 months of follow-up (DB period and up to 6 months of the open-label extension). CV hospitalizations and HF events were evaluated over the DB period of 33 to 36 months. Differences between vutrisiran and placebo were evaluated in the overall population, and in those stratified by baseline tafamidis use. Results: In the overall population, vutrisiran reduced the risk of ACM (HR: 0.64; 95% CI: 0.46-0.88) and CV mortality (HR: 0.67; 95% CI: 0.47-0.96) vs placebo. Vutrisiran also reduced the risk of a composite of CV mortality and CV events (HR: 0.72; 95% CI: 0.55-0.94), and lowered rates of CV hospitalizations (rate ratio [RR]: 0.75; 95% CI: 0.62-0.91), urgent HF visits (RR: 0.54; 95% CI: 0.30-0.98), and HF hospitalizations (RR: 0.67; 95% CI: 0.52-0.86) vs placebo. Consistent trends were seen regardless of baseline tafamidis use. Conclusions: Consistent with the primary trial results, vutrisiran reliably reduced the risk of ACM, CV mortality, CV hospitalizations, HF hospitalizations, and urgent HF visits vs placebo in patients with ATTR-CM. (HELIOS-B: A Study to Evaluate Vutrisiran in Patients With Transthyretin Amyloidosis With Cardiomyopathy; NCT04153149

Lentiviral-mediated gene therapy restores B cell tolerance in Wiskott-Aldrich syndrome patients

Wiskott-Aldrich syndrome (WAS) is an X-linked immunodeficiency characterized by microthrombocytopenia, eczema, and high susceptibility to developing tumors and autoimmunity. Recent evidence suggests that B cells may be key players in the pathogenesis of autoimmunity in WAS. Here, we assessed whether WAS protein deficiency (WASp deficiency) affects the establishment of B cell tolerance by testing the reactivity of recombinant antibodies isolated from single B cells from 4 WAS patients before and after gene therapy (GT). We found that pre-GT WASp-deficient B cells were hyperreactive to B cell receptor stimulation (BCR stimulation). This hyperreactivity correlated with decreased frequency of autoreactive new emigrant/transitional B cells exiting the BM, indicating that the BCR signaling threshold plays a major role in the regulation of central B cell tolerance. In contrast, mature naive B cells from WAS patients were enriched in self-reactive clones, revealing that peripheral B cell tolerance checkpoint dysfunction is associated with impaired suppressive function of WAS regulatory T cells. The introduction of functional WASp by GT corrected the alterations of both central and peripheral B cell tolerance checkpoints. We conclude that WASp plays an important role in the establishment and maintenance of B cell tolerance in humans and that restoration of WASp by GT is able to restore B cell tolerance in WAS patients

Agammaglobulinaemia despite terminal B-cell differentiation in a patient with a novel LRBA mutation

Mutations in lipopolysaccharide-responsive vesicle trafficking, beach and anchor-containing protein (LRBA) cause immune deficiency and inflammation. Here, we are reporting a novel homozygous mutation in LRBA allele in 7-year-old Omani boy, born to consanguineous parents. He presented with type 1 diabetes, autoimmune haematological cytopenia, recurrent chest infections and lymphocytic interstitial lung disease. The patient was treated with CTLA4-Ig (abatacept) with good outcome every 2 weeks for a period of 3 months. He developed complete IgG deficiency, but remarkably, histological examination revealed germinal centres and plasma cells in lymphoid and inflamed lung tissue. Further charatecterisation showed these cells to express IgM but not IgG. This ex vivo analysis suggests that LRBA mutation confers a defect in class switching despite plasma cell formation

Impact of Vutrisiran on Cardiac Biomarkers in Patients With Transthyretin Amyloidosis With Cardiomyopathy From HELIOS-B

Background: Before the development of disease-modifying therapies for transthyretin amyloidosis cardiomyopathy (ATTR-CM), N-terminal prohormone of B-type natriuretic peptide (NT-proBNP) and troponin I/T were recognized as independent prognostic biomarkers of mortality. This study evaluated the prognostic value of these biomarkers in a contemporary patient population and the impact of vutrisiran, an RNA interference therapeutic that rapidly knocks down circulating transthyretin, on biomarker levels. / Objectives: This study sought to evaluate the association between risk of cardiovascular events and all-cause mortality with baseline NT-proBNP and troponin I levels and changes from baseline at month 6 in patients from HELIOS-B and explore how vutrisiran impacts biomarkers over time. / Methods: In HELIOS-B, a double-blind, placebo-controlled study, 655 patients with ATTR-CM were randomized 1:1 to receive vutrisiran or placebo for up to 36 months. The primary endpoint was a composite outcome of all-cause mortality and recurrent cardiovascular events. All-cause mortality through 42 months was a secondary endpoint. NT-proBNP and troponin I were assessed as prespecified exploratory endpoints. / Results: Baseline NT-proBNP and troponin I levels were independently associated with risks of the composite outcome and all-cause mortality (P < 0.0001 for both biomarkers and endpoints). At month 6, increases in NT-proBNP from baseline were associated with higher risk of the composite outcome and all-cause mortality, and decreases in troponin I were associated with a lower risk of the composite outcome. At month 30, the median changes from baseline of NT-proBNP and troponin I were 753 pg/mL (Q1-Q3: −8 to 2,573 pg/mL) and 9.7 pg/mL (Q1-Q3: −6.3 to 41.2 pg/mL) in the placebo arm and 118 pg/mL (Q1-Q3: −419 to 911 pg/mL) and −5.8 pg/mL (Q1-Q3: −25.0 to 10.0 pg/mL) in the vutrisiran arm. The geometric mean fold-change ratios (vutrisiran/placebo) were 0.68 (95% CI: 0.61-0.76) for NT-proBNP and 0.68 (95% CI: 0.62-0.75) for troponin I (P < 0.0001 for both). / Conclusions: Patterns of associations between biomarkers and adverse outcomes support the importance of early treatment initiation and the potential for risk reduction in patients with ATTR-CM. Vutrisiran maintained stable or reduced levels of both biomarkers consistent with the benefit of treatment in reducing the risk of cardiovascular events and all-cause mortality. (HELIOS-B: A Study to Evaluate Vutrisiran in Patients With Transthyretin Amyloidosis With Cardiomyopathy; NCT04153149

Prospective Newborn Screening for SCID in Germany: A First Analysis by the Pediatric Immunology Working Group (API)

Background: T-cell receptor excision circle (TREC)-based newborn screening (NBS) for severe combined immunodeficiencies (SCID) was introduced in Germany in August 2019. / Methods: Children with abnormal TREC-NBS were referred to a newly established network of Combined Immunodeficiency (CID) Clinics and Centers. The Working Group for Pediatric Immunology (API) and German Society for Newborn Screening (DGNS) performed 6-monthly surveys to assess the TREC-NBS process after 2.5 years. / Results: Among 1.9 million screened newborns, 88 patients with congenital T-cell lymphocytopenia were identified (25 SCID, 17 leaky SCID/Omenn syndrome (OS)/idiopathic T-cell lymphocytopenia, and 46 syndromic disorders). A genetic diagnosis was established in 88%. Twenty-six patients underwent hematopoietic stem cell transplantation (HSCT), 23/26 within 4 months of life. Of these, 25/26 (96%) were alive at last follow-up. Two patients presented with in utero onset OS and died after birth. Five patients with syndromic disorders underwent thymus transplantation. Eight syndromic patients deceased, all from non-immunological complications. TREC-NBS missed one patient, who later presented clinically, and one tracking failure occurred after an inconclusive screening result. / Conclusion: The German TREC-NBS represents the largest European SCID screening at this point. The incidence of SCID/leaky SCID/OS in Germany is approximately 1:54,000, very similar to previous observations from North American and European regions and countries where TREC-NBS was implemented. The newly founded API-CID network facilitates tracking and treatment of identified patients. Short-term HSCT outcome was excellent, but NBS and transplant registries will remain essential to evaluate the long-term outcome and to compare results across the rising numbers of TREC-NBS programs across Europe