Sutimlimab Research Articles

Sustained Complement C1s Inhibition with Sutimlimab in Patients with Cold Agglutinin Disease Results in Continued Efficacy during Part B of the Randomized Placebo-Controlled Phase 3 Cadenza Study (NCT03347422)

Background: Cold agglutinin disease (CAD) is a rare chronic autoimmune hemolytic anemia characterized by classical complement pathway (CP)-mediated hemolysis. Sutimlimab (SUT) is a first-in-class humanized monoclonal antibody that prevents CP activation by selectively inhibiting C1s; both the alternative and lectin pathways remain intact. In the randomized, double-blind, placebo-controlled Part A (26 weeks) of Phase 3 CADENZA, SUT treatment resulted in rapid and sustained improvements in hemoglobin (Hb), hemolytic markers and quality of life (QoL). Aims: To report the long-term safety and efficacy of SUT treatment in patients with CAD from the open-label Part B extension of CADENZA. Methods: In Part A, eligible patients with CAD without a history of recent blood transfusion (≤1 during previous 12 months; 0 during last 6 months), received SUT or placebo (PBO) through intravenous infusions on Days 0 and 7, then biweekly. All patients completing Part A were eligible to enter Part B and receive biweekly SUT for ≥1 year after the last patient completed Part A. Efficacy data up to Week 79 as well as the last available patients' values are reported. Efficacy endpoints included change from baseline (BL) in Hb, hemolytic and pharmacodynamic markers, Functional Assessment of Chronic Illness Therapy (FACIT)-Fatigue, and blood transfusions. Safety data was recorded throughout the study; treatment emergent adverse event (TEAE) and serious TEAE (TESAE). Results: Of the 42 patients enrolled in Part A, 39 completed Part A and entered Part B, with 32 (82.1%) completing Part B; 7 (17.9%) patients discontinued the study prematurely, due to TESAE (n=1), lack of efficacy (n=3), withdrawal of consent (n=2) and withdrawal by sponsor (n=1). SUT treatment rapidly improved Hb levels; mean (SE) Hb at the end of Part A was 11.51 (0.40) g/dL and 9.43 (0.40) g/dL for SUT and PBO groups, respectively. In Part B, improvements in Hb were sustained in the SUT group and the ex-PBO group saw rapid and comparable increases in Hb upon initiation of SUT; at Week 79 mean (SE) Hb levels were 11.86 (0.54) g/dL and 11.76 (0.58) g/dL in the SUT only and ex-PBO groups, respectively (Panel A). Mean total bilirubin was normalized with SUT treatment in Part A and sustained in Part B; similar decreases were observed for patients in the ex-PBO group when they started receiving SUT in Part B (Panel B). Improvements in mean [SE] FACIT-Fatigue scores (BL: 32.96 [1.79]) observed in Part A were sustained in Part B in the SUT only group (44.31 [2.19] at Week 87); the mean FACIT-Fatigue score increased to comparable levels in the ex-PBO group (41.40 [2.71] at Week 87). Improvements in Hb, bilirubin, and FACIT-Fatigue correlated with normalization of C4 and near-complete inhibition of CP activity, that was maintained through the end of treatment. Reductions in mean absolute reticulocyte count and increases in haptoglobin levels observed with SUT treatment in Part A were maintained in Part B, and upon initiation of SUT in Part B, the ex-PBO group reached comparable levels. In Part B, 9 (23.1%) patients received a ≥1 transfusion. Thirty-six (92.3%) patients experienced ≥1 TEAE in Part B. Seven (17.9%) patients experienced a total of 11 TESAEs; one TESAE of hypertension was assessed as related to SUT by the investigator. Thromboembolic events (transient ischemic attack [n=1]; deep vein thrombosis [n=1]) were observed in 2 (5.1%) patients with underlying risk factors for thromboembolism. Both events were assessed as non-serious and unrelated to SUT by the Investigator. One TESAE of infection (urinary tract infection Grade ≥3) was reported. No meningococcal infections, serious events of hypersensitivity, anaphylaxis or systemic lupus erythematosus were reported. One patient with a history of tobacco use (received PBO in Part A) experienced a TESAE of squamous cell carcinoma of the lung with fatal outcome. SUT was withdrawn due to this TESAE prior to the patient's death. Conclusion: Long-term treatment with SUT, an anti-C1s CP inhibitor, maintained mean Hb levels >11 g/dL, achieved sustained normalization of bilirubin and led to clinically meaningful improvements of FACIT-Fatigue scores, while maintaining a favourable safety profile. Improvements in anemia, inhibition of hemolysis and favourable effects on QoL were rapidly achieved and sustained to a similar extent in those patients administered SUT throughout the study and those who switched to SUT treatment in Part B. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Concomitant Use of Sutimlimab and COVID-19 Vaccines in Patients with Cold Agglutinin Disease from the Phase 3 Cardinal and Cadenza Studies

Background: Cold agglutinin disease (CAD) is a rare autoimmune hemolytic anemia, characterized by chronic hemolysis mediated by classical complement pathway activation. The ongoing COVID-19 pandemic has posed an additional challenge in treating patients with CAD. Anti-CD20 therapies (commonly used off-label to treat CAD) increase the risk of serious COVID-19 infection and reduce the immune response to COVID-19 vaccines. Recent evidence has also shown a correlation between CAD exacerbations and both COVID-19 and COVID-19 vaccines; raising concern amongst clinicians as CAD patients are usually elderly with comorbidities and will likely require additional boosters during the ongoing pandemic. Sutimlimab (SUT), recently FDA approved for patients with CAD, is a first-in-class humanized monoclonal antibody which selectively targets C1s in the classical complement pathway; addressing the underlying mechanism of hemolysis in CAD. In the Phase 3 CARDINAL (NCT03347396) and CADENZA (NCT03347422) studies, SUT treatment led to rapid and sustained increases in hemoglobin and clinically meaningful improvements in fatigue and was generally well tolerated - reported adverse events (AE) were consistent with elderly populations. Both studies spanned the period before and during the pandemic; investigators were advised to vaccinate enrolled patients without stopping SUT treatment. However, the impact of SUT on immune response to COVID-19 vaccination is unknown. Objective: To explore concomitant use of COVID-19 vaccines and SUT in patients with CAD Methods: Post-hoc analysis from the open label extension (OLE) part of the CADENZA and CARDINAL studies. COVID-19 cases/diagnoses were collected via the regular AE reporting system. Data on tolerability to COVID-19 vaccine was collected through AE reports. Immunogenicity to COVID-19 vaccines was analyzed in a subset of patients fully vaccinated (2 doses) against COVID-19 and had consented to the use of stored samples (collected no later than 6 months after vaccination). Anti-Sars-CoV-2 Spike (EUROIMMUN Anti-SARS-CoV-2 ELISA) and anti-Sars-CoV-2 Nucleocapsid (Abbott Architect i2000 SR) IgG titers were measured. Three patients who tested positive for COVID-19 during Part A of both studies were excluded from the immunogenicity analysis. Results: Of the 61 completers from both studies, 47 received at least one dose of a COVID-19 vaccine; 14 received none; 11 had an additional booster. All participants, regardless of vaccination status, had similar demographic and clinical characteristics. Among those vaccinated, most (83%) received both doses during the studies; of these, mRNA vaccines were the most common (79%). The mean inter-dose interval for fully vaccinated patients (n=37) was 38 days; those who received 1 booster (n=11) had a mean of 165 days between the last dose and booster. No COVID-19 cases were reported during the OLE. Ten AEs were reported in 8 patients during the 7 days after any vaccine dose, but none more than once, and there were no serious AEs. SUT therapy was postponed/skipped twice due to vaccine administration, at the investigator's discretion. Anemia and hemolysis markers, including hemoglobin and total bilirubin, were measured after vaccination to assess its impact on hemolytic activity. No indications of hemolytic exacerbation were observed (Table 1). The immunogenicity analysis comprised 27 patients. All patients developed an immune response post-vaccination, measured via positive IgG anti-spike antibodies (Figure 1). The mean time between last dose and serum collection was 65 days (range: 25-137). Antibody titers were similar irrespective of gender or age. A further analysis performed on 6 patients with booster vaccinations demonstrated elevated immune responses pre to post booster (mean [95% CI] log10 titer change: 1.82 [0.79-2.85]). To rule out previous asymptomatic COVID-19 infection, anti-nucleocapsid SARS-Cov-2 IgG antibodies were assayed and were negative in all cases. Conclusions: COVID-19 vaccination response was not impaired in patients with CAD being treated with SUT. COVID-19 vaccines were well tolerated, and there were no signs of increased hemolytic marker activity following COVID-19 vaccination in patients receiving SUT. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Treating Cold Agglutinin Disease with Sutimlimab

Clinical complications of cold agglutinin disease (CAD) include hemolytic anemia and acrocyanosis. The disease is driven by IgM autoantibodies that