Complement-mediated hemolysis persists year round in patients with cold agglutinin disease

Sustained improvements in patient-reported outcomes after long-term sutimlimab in patients with cold agglutinin disease: results from the CADENZA study open-label extension

Background

Cold agglutinin disease (CAD) is a rare subtype of autoimmune haemolytic anaemia characterised by classical complement pathway-mediated haemolysis, fatigue, and poor quality of life (QoL). Sutimlimab, a C1s inhibitor, rapidly halted haemolysis, and improved patient-reported outcomes (PROs) in patients with CAD in two phase 3 trials (CARDINAL and CADENZA). Here we report PROs from the CADENZA open-label extension (Part B).

Methods

The first patient was enrolled in CADENZA (NCT03347422) in March 2018 (Part A) and the last patient completed the study in December 2021 (Part B). All patients who completed the 26-week Part A were eligible to receive biweekly doses of sutimlimab in Part B for up to 1 year after the last patient completed Part A. PROs were assessed throughout Part B, until the last on-treatment visit with available assessment (LV), and after a 9-week washout.

Findings

In total, 32/39 patients completed Part B; median Part B treatment duration: 99 weeks. Patients switching from placebo to sutimlimab in Part B experienced rapid improvement in Functional Assessment of Chronic Illness Therapy (FACIT)-Fatigue score and other PROs. Sustained, clinically important improvements in FACIT-Fatigue were observed throughout Part B in patients who switched to sutimlimab and those continuing sutimlimab treatment (combined-group mean [SE] change from baseline at LV: 8.8 [2.1]). Similarly, the combined-group mean [SE] change for 12-Item Short Form Health Survey physical (4.9 [1.7]) and mental (4.0 [1.8]) component scores exceeded clinically important changes from baseline at LV. EuroQol visual analogue scale showed consistent and sustained increases from baseline with sutimlimab treatment. Following a 9-week washout, all PROs approached baseline values.

Interpretation

Continued inhibition of the classical complement pathway with sutimlimab results in meaningful long-term improvements in PROs (fatigue and QoL) in patients with CAD.

Funding

Sanofi.

Long-term efficacy and safety of continued complement C1s inhibition with sutimlimab in cold agglutinin disease: CADENZA study Part B

Background

Cold agglutinin disease (CAD) is a rare autoimmune haemolytic anaemia mediated by the classical complement pathway (CP). Sutimlimab selectively targets complement C1s inhibiting classical CP activation. In CADENZA Part A (26-weeks), a placebo-controlled study in patients without recent transfusion history, sutimlimab reduced haemolysis, anaemia, and fatigue, and was generally well tolerated.

Methods

The CADENZA study (NCT03347422) started in March 2018 (Part A) and completed in December 2021 (Part B). All patients in Part B were eligible to receive sutimlimab for up to 1 year after the last patient completed Part A. Efficacy and safety was assessed throughout Part B, until the last on-treatment visit with available assessment (LV), and after a 9-week washout.

Findings

In total, 32/39 patients completed Part B; median treatment duration: 99 weeks. Similar sustained improvements in haemolysis, anaemia, and quality of life were observed in patients switching to sutimlimab and those continuing sutimlimab. Mean LV values for the combined group (ie, placebo-to-sutimlimab group and sutimlimab-to-sutimlimab group) improved from baseline for haemoglobin (≥11.0 g/dL on-treatment vs 9.3 g/dL at baseline), bilirubin (≤20.0 μmol/L on-treatment vs 35.0 μmol/L at baseline), and FACIT-Fatigue scores. Following a 9-week washout, inhibition of CP activity was reversed, and haemolytic markers approached baseline levels. Overall, sutimlimab was generally well tolerated throughout the study. No patients developed systemic lupus erythematosus or meningococcal infections. During the 9-week washout, most adverse events could be attributed to recurrence of underlying CAD.

Interpretation

The CADENZA Part B results support the sustained efficacy and safety of sutimlimab for treatment of CAD; however, upon discontinuation disease activity reoccurs.

Funding

Sanofi.

Clinical value of combined predictors of RET%, γ-GT, LDH in the ABO neonatal hemolytic disease

Objective

The purpose of this study is to examine the prognostic significance of the amalgamated indicators, reticulocyte percentage (RET%), lactate dehydrogenase (LDH), and γ-Glutamyltransferase (γ-GT), in neonatal ABO hemolytic disease.

Methods

A total of 137 hospitalized children with pathological jaundice were included. Based on their medical conditions, they were categorized into two groups, hemolytic (67 cases) and non-hemolytic (70 cases). Pearson linear correlation and binary logistic multivariate analysis were used to analyze LDH, γ-GT, RET% and hemolysis. Furthermore, the predictive value of the combined predictors of RET%, LDH, and γ-GT on ABO neonatal hemolytic disease was evaluated using the ROC curve analysis.

Results

The laboratory indexes of the two groups were subject to analysis using binary logistic regression to identify suspicious influencing factors. The study revealed that RET%, LDH, and γ-GT were independent risk factors for hemolysis. Pearson linear correlation analysis indicated a positive correlation between LDH and γ-GT with RET% (r = 0.529, P < 0.01; r = 0.526, P = <0.01, respectively). Furthermore, the predictive value of each combined predictor was obtained using the ROC curve, and it was observed that combined predictor L (RET% + LDH + γ-GT)>L1 (RET% + LDH)>L2 (RET% + γ-GT).

Conclusion

Combined predictor L (RET% + LDH + γ-GT)demonstrate its optimal diagnostic efficacy, offering a novel approach towards diagnosing early-onset ABO hemolytic disease of the newborn.

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.

Collection and processing of hematopoietic progenitor cell products at risk of presenting with cold agglutination

BACKGROUND AIMS

Cold agglutinins are commonly identified in transfusion laboratories and are defined by their ability to agglutinate erythrocytes at 3-4°C, with most demonstrating a titer >64. Similarly, cryoglobulins can precipitate from plasma when temperatures drop below central body temperature, resulting in erythrocyte agglutination. Thankfully, disease associated from these autoantibodies is rare, but unfortunately, such temperature ranges are routinely encountered outside of the body's circulation, as in an extracorporeal circuit during hematopoietic progenitor cell (HPC) collection or human cell therapy laboratory processing. When agglutination occurs ex vivo, complications with the collection and product may be encountered, resulting in adverse events or product loss. Here, we endeavor to share our experience in preventing and responding to known cases at risk of or spontaneous HPC agglutination in our human cell therapy laboratory.

CASE REPORTS

Four cases of HPC products at risk for, or spontaneously, agglutinating were seen at our institution from 2018 to 2020. Planned modifications occurred, including ambient room temperature increases, tandem draw and return blood warmers, warm product transport and extended post-thaw warming occurred. In addition, unplanned modifications were undertaken, including warm HPC product processing and plasma replacement of the product when spontaneous agglutination of the product was identified. All recipients successfully engrafted after infusion.

CONCLUSIONS

While uncommon, cold agglutination of HPC products can disrupt standard processes of collection and processing. Protocol modifications can circumvent adverse events for the donor and minimize product loss. Such process modifications should be considered in individuals with known risks for agglutination going to HPC donation/collection.

Sutimlimab suppresses SARS-CoV-2 mRNA vaccine-induced hemolytic crisis in a patient with cold agglutinin disease

Cold agglutinin disease (CAD) is a rare form of acquired autoimmune hemolytic anemia driven mainly by antibodies that activate the classical complement pathway. Several patients with CAD experience its development or exacerbation of hemolysis after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection or after receiving the SARS-CoV-2 mRNA vaccine. Therefore, these patients cannot receive an additional SARS-CoV-2 mRNA vaccination and have a higher risk of severe SARS-CoV-2 infection. Sutimlimab is a monoclonal antibody that inhibits the classical complement pathway of the C1s protein and shows rapid and sustained inhibition of hemolysis in patients with CAD. However, whether sutimlimab could also inhibit hemolysis caused by SARS-CoV-2 mRNA vaccination is uncertain. Here, we present the case of a 70-year-old man with CAD who repeatedly experienced a hemolytic crisis after receiving SARS-CoV-2 mRNA vaccines. The patient eventually underwent SARS-CoV-2 mRNA vaccination safely, without hemolytic attack, under classical pathway inhibition therapy with sutimlimab. This report suggests that appropriate sutimlimab administration can suppress SARS-CoV-2 mRNA vaccination-induced CAD exacerbation, and that it could be a preventive strategy to minimize hemolytic attacks in susceptible populations.

Sutimlimab in patients with cold agglutinin disease: results of the randomized placebo-controlled phase 3 CADENZA trial

Sutimlimab, a first-in-class humanized immunoglobulin G4 (IgG4) monoclonal antibody that selectively inhibits the classical complement pathway at C1s, rapidly halted hemolysis in the single-arm CARDINAL study in recently transfused patients with cold agglutinin disease (CAD). CADENZA was a 26-week randomized, placebo-controlled phase 3 study to assess safety and efficacy of sutimlimab in patients with CAD without recent (within 6 months prior to enrollment) transfusion history. Forty-two patients with screening hemoglobin ≤10 g/dL, elevated bilirubin, and ≥1 CAD symptom received sutimlimab (n = 22) or placebo (n = 20) on days 0 and 7 and then biweekly. Composite primary endpoint criteria (hemoglobin increase ≥1.5 g/dL at treatment assessment timepoint [mean of weeks 23, 25, 26], avoidance of transfusion, and study-prohibited CAD therapy [weeks 5-26]) were met by 16 patients (73%) on sutimlimab, and 3 patients (15%) on placebo (odds ratio, 15.9 [95% confidence interval, 2.9, 88.0; P < .001]). Sutimlimab, but not placebo, significantly increased mean hemoglobin and FACIT-Fatigue scores at treatment assessment timepoint. Sutimlimab normalized mean bilirubin by week 1. Improvements correlated with near-complete inhibition of the classical complement pathway (2.3% mean activity at week 1) and C4 normalization. Twenty-one (96%) sutimlimab patients and 20 (100%) placebo patients experienced ≥1 treatment-emergent adverse event. Headache, hypertension, rhinitis, Raynaud phenomenon, and acrocyanosis were more frequent with sutimlimab vs placebo, with a difference of ≥3 patients between groups. Three sutimlimab patients discontinued owing to adverse events; no placebo patients discontinued. These data demonstrate that sutimlimab has potential to be an important advancement in the treatment of CAD. This trial was registered at www.clinicaltrials.gov as #NCT03347422.

Sutimlimab for treatment of cold agglutinin disease: why, how and for whom?

Therapies for cold agglutinin disease have been directed at the pathogenic B-cell clone. Sutimlimab, a monoclonal antibody that targets C1s, is the first complement inhibitor to be extensively studied in cold agglutinin disease. Sutimlimab selectively blocks the classical activation pathway and leaves the alternative and lectin pathways intact. Trials have documented high response rates with rapid improvement in hemolysis, hemoglobin levels and fatigue scores and low toxicity. Sutimlimab was recently approved in the USA. This drug appears to be particularly useful in severely anemic patients who require a rapid response, in acute exacerbations that do not resolve spontaneously and in patients in whom chemoimmunotherapy is contraindicated or has failed. The choice of therapy in cold agglutinin disease should be individualized.