Daratumumab monotherapy in refractory warm autoimmune hemolytic anemia and cold agglutinin disease.

ABSTRACT: Autoimmune hemolytic anemia (AIHA) is a rare autoantibody-mediated disease. For steroid and/or rituximab-refractory AIHA, there is no consensus on optimal treatment. Daratumumab, a monoclonal antibody targeting CD38, could be beneficial by suppression of CD38+ plasma cells and thus autoantibody secretion. In addition, because CD38 is also expressed by activated T cells, daratumumab may also act via immunomodulatory effects. We evaluated the efficacy and safety of daratumumab monotherapy in an international retrospective study including 19 adult patients with heavily pretreated refractory AIHA. In warm AIHA (wAIHA, n = 12), overall response was 50% with a median response duration of 5.5 months (range, 2-12), including ongoing response in 2 patients after 6 and 12 months. Of 6 nonresponders, 4 had Evans syndrome. In cold AIHA (cAIHA, n = 7) overall hemoglobin (Hb) response was 57%, with ongoing response in 3 of 7 patients. One additional patient with nonanemic cAIHA was treated for severe acrocyanosis and reached a clinical acrocyanosis response as well as a Hb increase. Of 6 patients with cAIHA with acrocyanosis, 4 had improved symptoms after daratumumab treatment. In 2 patients with wAIHA treated with daratumumab, in whom we prospectively collected blood samples, we found complete CD38+ T-cell depletion after daratumumab, as well as altered T-cell subset differentiation and a severely diminished capacity for cell activation and proliferation. Reappearance of CD38+ T cells coincided with disease relapse in 1 patient. In conclusion, our data show that daratumumab therapy may be a treatment option for refractory AIHA. The observed immunomodulatory effects that may contribute to the clinical response deserve further exploration.

Real-world use of thrombopoietin receptor agonists for the management of immune thrombocytopenia in adult patients in the United Kingdom: Results from the TRAIT study.

Few studies have reported the real-world use of both romiplostim and eltrombopag in immune thrombocytopenia (ITP). TRAIT was a retrospective observational study aimed to evaluate the platelet responses and adverse effects associated with the use of these thrombopoietin receptor agonists (TPO-RAs) in adult patients with ITP in the United Kingdom. Of 267 patients (median age at diagnosis, 48 years) with ITP (primary ITP [n = 218], secondary ITP [n = 49]) included in the study, 112 (42%) received eltrombopag and 155 (58%) received romiplostim as the first prescribed TPO-RA. A platelet count ≥30 × 109/L was achieved in 89% of patients with the first TPO-RA treatments, while 68% achieved a platelet count ≥100 × 109/L. Treatment-free response (TFR; platelet count ≥30 × 109/L, 3 months after discontinuing treatment) was achieved by 18% of the total patients. Overall, 61 patients (23%) switched TPO-RAs, most of whom achieved platelet counts ≥30 × 109/L with the second TPO-RA (23/25 who switched from eltrombopag to romiplostim [92%]; 28/36 who switched from romiplostim to eltrombopag [78%]). TFR was associated with secondary ITP, early TPO-RA initiation after diagnosis, the presence of comorbidity and no prior splenectomy or treatment with steroids or mycophenolate mofetil. Both TPO-RAs had similar efficacy and safety profiles to those reported in clinical studies.

Development of the Cold Agglutinin Disease Symptoms and Impact Questionnaire (CAD-SIQ).

OBJECTIVES: Cold agglutinin disease (CAD) is a rare autoimmune hemolytic anemia. This study aimed to identify disease-related symptoms and impacts important to patients with CAD, and to develop a novel CAD-specific patient-reported outcome measure. METHODS: Adults with CAD were randomly selected from a United States patient panel to participate in concept elicitation (CE) interviews to identify important symptoms and impacts or cognitive debriefing (CD) interviews to assess the comprehension and relevance of the draft item set. RESULTS: Overall, 37 adults were included (mean [range] age 67.2 [35-87] years). In CE interviews (n = 16), the most frequently reported CAD-related symptoms were reactions to cold environments and fatigue (both 93.8%). CAD had negative impacts on enjoyable activities (81.3%) and daily activities (75.0%). Following CE, standard survey methodological principles were used to develop a draft item pool of 14 concepts. Items were refined through three iterative rounds of CD interviews (n = 21), yielding 11 final items: fatigue; cold sensitivity; dyspnea; wearing extra clothing; limited physical, social, and enjoyable activities; difficulty with usual activities; mood; frustration; and anxiety/stress. CONCLUSIONS: The novel 11-item CAD-Symptoms and Impact Questionnaire provides a measure of the symptoms and impacts of CAD that are important to patients.

Recent advances in understanding spleen tyrosine kinase (SYK) in human biology and disease, with a focus on fostamatinib.

Spleen tyrosine kinase (SYK) is an important regulatory molecule of signal transduction pathways involved in the pathogenesis of autoimmune diseases such as immune thrombocytopenia (ITP), and the SYK-signaling pathway has emerged as a potential target for the treatment of numerous diseases. The aim of this narrative review is to summarize the biological properties of SYK and its involvement in disease pathways, provide an update on SYK inhibitors in the treatment of ITP, and consider other potential applications. Fostamatinib, the only licensed SYK inhibitor to date, produces clinical response in ITP patients, including those who are refractory to other treatments. It appears to reduce the risk of thrombotic events and may therefore be a drug to consider for patients with an increased thrombotic risk. Encouraging results have also been obtained in the treatment of warm autoimmune hemolytic anemia. Several other SYK inhibitors have entered clinical trials for a range of indications, reflecting the ability of these drugs to affect multiple signaling pathways. SYK inhibitors have the potential to target several aspects of COVID-19 pathogenesis including thrombosis, without affecting normal hemostasis, and data from the first study of fostamatinib in COVID-19 are encouraging. It is hoped that ongoing trials in autoimmune indications other than ITP, as well as in hematological malignancies and other disorders, confirm the promise of SYK inhibitors.

Immune thrombocytopenia (ITP) is an autoimmune disease that usually happens when your immune system mistakenly attacks and destroys platelets, which are cells that help blood to clot. Individuals with ITP can experience easy or excessive bruising and bleeding. Scientists have identified that an enzyme called spleen tyrosine kinase (SYK) is involved in numerous biological processes that are associated with the immune system response, inflammation, and some types of cancer in humans. Therefore, it has become a target for new drugs which inhibit the action of SYK. In this review article, the authors provide a summary of the biological properties and actions of SYK and its involvement in various diseases, discuss information about drugs that have been developed as SYK inhibitors for the treatment of ITP, and consider other potential uses for drugs that inhibit SYK. Although several drugs are being developed, the only SYK inhibitor that is currently available for the treatment of ITP is a drug called fostamatinib. In patients with ITP, including those who no longer respond to other treatments, fostamatinib has been shown to improve platelet counts and reduce bleeding events. Researchers are also currently investigating the use of drugs that inhibit SYK, including fostamatinib, for the potential treatment of other diseases associated with inflammation (e.g. rheumatoid arthritis, COVID-19), autoimmunity (e.g. warm autoimmune hemolytic anemia), and blood cancers (e.g. lymphoma, chronic lymphocytic leukemia, and acute myeloid leukemia).

Sutimlimab provides clinically meaningful improvements in patient-reported outcomes in patients with cold agglutinin disease: Results from the randomised, placebo-controlled, Phase 3 CADENZA study.

Cold agglutinin disease (CAD) is a rare chronic autoimmune haemolytic anaemia, driven mainly by classical complement pathway activation, leading to profound fatigue and poor quality of life. In the Phase 3 CADENZA trial, sutimlimab-a C1s complement inhibitor-rapidly halted haemolysis, increased haemoglobin levels and improved fatigue versus placebo in patients with CAD without a recent history of transfusion. Patient-reported outcomes (PROs) included Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-Fatigue), 12-Item Short Form Health Survey (SF-12), EuroQol visual analogue scale (EQ-VAS), Patient Global Impression of Change (PGIC) and Patient Global Impression of (fatigue) Severity (PGIS). Sutimlimab resulted in significant rapid and meaningful improvements versus placebo in PROs. From Week 1, the FACIT-Fatigue mean score increased >5 points above baseline (considered a clinically important change [CIC]). Least-squares (LS) mean change in FACIT-Fatigue score from baseline to treatment assessment timepoint was 10.8 vs. 1.9 points (sutimlimab vs. placebo; p < 0.001). Improvements in physical (PCS) and mental (MCS) component scores of the SF-12 were also considered CICs (LS mean changes from baseline to Week 26: PCS 5.54 vs. 1.57 [p = 0.064]; MCS 5.65 vs. -0.48 [p = 0.065]). These findings demonstrate that in addition to improving haematologic parameters, sutimlimab treatment demonstrates significant patient-reported benefits. Study registered at www.clinicaltrials.gov: NCT03347422.

Long-term risk of relapse in immune-mediated thrombotic thrombocytopenic purpura and the role of anti-CD20 therapy.

Disease relapse is recognized as a risk in immune-mediated thrombotic thrombocytopenic purpura (iTTP) after treatment of the acute presenting episode. Identification of patients at risk of relapse and its patterns are yet to be clearly established. We reviewed patients with iTTP having had >3 years of follow-up over 10 years in the United Kingdom to identify patient characteristics for relapse, assess relapse rates and patterns, and response to anti-CD20 therapy in those with a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS13) relapses (ADAMTS13 activity of <20% without thrombocytopenia). We identified 443 patients demonstrating relapse rates of 40% at 5-year follow-up. At 10-year follow-up, no difference in relapse was observed irrespective of whether rituximab was used at acute presentation (P = .39). Black Caribbean ethnicity increased the risk of disease relapse in the British population. There was a distinct population of patients (6%) that relapsed early with subsequent frequent relapses occurring on average within 2 years (average time to relapse in subgroup, 1.7 years). Overall, nearly 60% of relapses described were ADAMTS13 relapses, with subsequent treatment reducing the risk of progression to clinical relapses. We demonstrate that iTTP diagnosed in the latter part of the study period had lower rates of clinical relapses (22.6% vs 11.1%, P = .0004) with the advent of regular monitoring and preemptive rituximab. In ADAMTS13 relapses, 96% responded to anti-CD20 therapy, achieving ADAMTS13 activity of >20%. Anti-CD20 therapy was demonstrated to be an effective long-term treatment regardless of relapse pattern and there was no loss of this treatment response after subsequent treatment episodes.

Incidence of adult primary immune thrombocytopenia in England-An update.

BACKGROUND: Adult primary immune thrombocytopenia (ITP) is a rare bleeding disorder of unknown cause. Recent estimates of its incidence and trend over time were acquired for England. METHOD: The primary ITP population (using ICD 10 code D693 and excluding secondary ITP cases; positive predictive value: 82.6%) was sourced from NHS Digital inpatient and outpatient. Incidence rate (IR) for England and by age groups, sex, and regions were calculated and trends were assessed using average annual percent change (AAPC). RESULTS: A total of 25 805 patients (mean age 59 years; females 57.8%) diagnosed between 2003 and 2014 was identified. IRs increased from 4.2/100 000 to 6.4/100 000 over this period (AAPC:4.3%). For all sex-specific age groups, the IRs significantly increased over time, except 18-29 years males. The greatest increase was among females aged 30-39 (AAPC:8.7%). In contrast, among ≥70 years, ITP was more common in males (highest IR among ≥80 years males: 23.9/100 000). England's average annual IR was 6.1/100 000 for 2010-14. An estimated 2.5/100 000 (based on UKITP Registry data) was estimated to require 1st line treatment whereas 2.4/100 000 would have 1st and 2nd line treatments within 6 months from diagnosis. IRs for London and East Midlands were the highest (6.5/100 000). CONCLUSIONS: This study found a rising incidence of primary ITP, with sharp increases among young women and elderly men. These findings put in context the impact of ITP on patients' lives and the healthcare services in England, especially with 17%-50% who may develop chronic ITP and require long-term care.

A real-world study of immune thrombocytopenia management during the COVID-19 pandemic in the UK.

The COVID-19 pandemic has created many challenges in the management of immune thrombocytopenic purpura (ITP). The recommendation for avoidance of steroids by WHO led to the off-licence use, supported by NHS England, of thrombopoietin mimetics (TPO-RA) for newly diagnosed or relapsed ITP. This is a real-world prospective study which investigated the treatment patterns and outcomes in this setting. Twenty-four hospitals across the UK submitted 343 cases. Corticosteroids remain the mainstay of ITP treatment, but TPO-RAs were more effective. Incidental COVID-19 infection was identified in a significant number of patients (9·5%), while 14 cases were thought to be secondary to COVID-19 vaccination.

Psychometric Evaluation of ITP Life Quality Index (ILQI) in a Global Survey of Patients with Immune Thrombocytopenia.

INTRODUCTION: Immune thrombocytopenia (ITP) is an autoimmune disorder caused by immunologic destruction of otherwise normal platelets. Patients and physicians differ in their views pertaining to the limitations imposed on patients' daily lives by ITP and its treatment. Poor understanding of ITP symptoms can result in misdiagnosis and complex treatment patterns, and affect patient health-related quality of life (HRQoL). The ITP Life Quality Index (ILQI) is a 10-item patient-reported outcome measure developed for clinical practice to aid discussions between patients and physicians. This research aimed to validate the psychometric properties of the ILQI using data collected in the ITP World Impact Survey (I-WISh). METHODS: I-WISh data containing responses to the ILQI from 1507 patients with ITP across 13 countries worldwide was subject to psychometric analysis to evaluate the structure, reliability and validity of the ILQI and assess scoring cut-offs. RESULTS: The ILQI has an overarching unidimensional structure, supporting a total score including all 10 items. Reliability was supported (Cronbach's alpha = 0.90). ILQI scores monotonically increased with ITP severity. ILQI scores correlated with measures of fatigue and emotional well-being, supporting construct validity. Differential item functioning (DIF) analyses showed that ILQI item responses were interpreted similarly between the USA and other Western countries. It was suggested that previous clinical cut-off score of 20 for "impaired HRQoL" was reduced to 17 and a cut-off of 23-25 (rather than 30) was suggested to assess "significantly impaired HRQoL". CONCLUSION: The validity and reliability of the ILQI to assess HRQoL of patients with ITP is supported. The revised cut-off scores for the ILQI will aid patient-centric decision-making.

Mycophenolate Mofetil for First-Line Treatment of Immune Thrombocytopenia.

BACKGROUND: Immune thrombocytopenia is a rare autoimmune disorder with associated bleeding risk and fatigue. Recommended first-line treatment for immune thrombocytopenia is high-dose glucocorticoids, but side effects, variable responses, and high relapse rates are serious drawbacks. METHODS: In this multicenter, open-label, randomized, controlled trial conducted in the United Kingdom, we assigned adult patients with immune thrombocytopenia, in a 1:1 ratio, to first-line treatment with a glucocorticoid only (standard care) or combined glucocorticoid and mycophenolate mofetil. The primary efficacy outcome was treatment failure, defined as a platelet count of less than 30×109 per liter and initiation of a second-line treatment, assessed in a time-to-event analysis. Secondary outcomes were response rates, side effects, occurrence of bleeding, patient-reported quality-of-life measures, and serious adverse events. RESULTS: A total of 120 patients with immune thrombocytopenia underwent randomization (52.4% male; mean age, 54 years [range 17 to 87]; mean platelet level, 7×109 per liter) and were followed for up to 2 years after beginning trial treatment. The mycophenolate mofetil group had fewer treatment failures than the glucocorticoid-only group (22% [13 of 59 patients] vs. 44% [27 of 61 patients]; hazard ratio, 0.41; range, 0.21 to 0.80; P = 0.008) and greater response (91.5% of patients having platelet counts greater than 100×109 per liter vs. 63.9%; P<0.001). We found no evidence of a difference between the groups in the occurrence of bleeding, rescue treatments, or treatment side effects, including infection. However, patients in the mycophenolate mofetil group reported worse quality-of-life outcomes regarding physical function and fatigue than those in the glucocorticoid-only group. CONCLUSIONS: The addition of mycophenolate mofetil to a glucocorticoid for first-line treatment of immune thrombocytopenia resulted in greater response and a lower risk of refractory or relapsed immune thrombocytopenia, but with somewhat decreased quality of life. (Funded by the U.K. National Institute for Health Research; FLIGHT ClinicalTrials.gov number, NCT03156452; EudraCT number, 2017-001171-23.).

Tapering and Discontinuation of Thrombopoietin Receptor Agonist Therapy in Patients with Immune Thrombocytopenia: Results from a Modified Delphi Panel.

BACKGROUND: Recent evidence suggests that in patients with immune thrombocytopenia (ITP) with a stable response on thrombopoietin receptor agonists, treatment may be tapered and/or discontinued. OBJECTIVES: The objective of this study was to provide a guide for tapering and discontinuation of TPO-RA therapy in patients with ITP, based on hematologist survey results, existing evidence, and expert consensus. PATIENTS/METHODS: UK hematologists completed a survey to characterize self-reported practice patterns related to TPO-RA tapering and discontinuation in patients with ITP. Using a modified Delphi panel approach, ITP experts developed consensus statements regarding the use of TPO-RA tapering and discontinuation. RESULTS: Survey respondents estimated that 30-34% of their patients were suitable for tapering or discontinuation and that 29-35% of these patients required treatment re-initiation after an average treatment-free interval of 86-106 days. No clear predictors of patient suitability or response to tapering or discontinuation were identified. The ITP expert consensus was that approximately 30% of patients are eligible for tapering and discontinuation, which may be considered after 6-12 months for patients demonstrating an adequate treatment response (platelet count >50,000/µL at ≥75% of assessments in the preceding 6 months). Treatment re-initiation may be considered if the platelet count decreases or if the patient becomes symptomatic. Individual differences need to be taken into account when considering TPO-RA tapering or discontinuation. CONCLUSIONS: Tapering and discontinuation of TPO-RA therapy may be considered for certain patients with ITP. Further study is needed to better predict patients likely to achieve sustained off-treatment responses after tapering and discontinuation.

Genetic and functional insights into CDA-I prevalence and pathogenesis.

BACKGROUND: Congenital dyserythropoietic anaemia type I (CDA-I) is a hereditary anaemia caused by biallelic mutations in the widely expressed genes CDAN1 and C15orf41. Little is understood about either protein and it is unclear in which cellular pathways they participate. METHODS: Genetic analysis of a cohort of patients with CDA-I identifies novel pathogenic variants in both known causative genes. We analyse the mutation distribution and the predicted structural positioning of amino acids affected in Codanin-1, the protein encoded by CDAN1. Using western blotting, immunoprecipitation and immunofluorescence, we determine the effect of particular mutations on both proteins and interrogate protein interaction, stability and subcellular localisation. RESULTS: We identify six novel CDAN1 mutations and one novel mutation in C15orf41 and uncover evidence of further genetic heterogeneity in CDA-I. Additionally, population genetics suggests that CDA-I is more common than currently predicted. Mutations are enriched in six clusters in Codanin-1 and tend to affect buried residues. Many missense and in-frame mutations do not destabilise the entire protein. Rather C15orf41 relies on Codanin-1 for stability and both proteins, which are enriched in the nucleolus, interact to form an obligate complex in cells. CONCLUSION: Stability and interaction data suggest that C15orf41 may be the key determinant of CDA-I and offer insight into the mechanism underlying this disease. Both proteins share a common pathway likely to be present in a wide variety of cell types; however, nucleolar enrichment may provide a clue as to the erythroid specific nature of CDA-I. The surprisingly high predicted incidence of CDA-I suggests that better ascertainment would lead to improved patient care.