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Blood Advances in a Different Vein Eculizumab Reduces Hemolysis and Transfusion Dependency in Patients With Cold Agglutin Disease Treatment with eculizumab, an in- hibitor of the terminal complement pathway, reduced hemolysis and transfusion-dependence in patients with cold agglutin disease (CAD). However, it had no effect on cold- induced circulatory symptoms, according to results from a phase II trial published in Blood Advances. “CAD is a rare form of hemo- lytic anemia caused by immuno- globulin M (IgM) autoantibodies against red blood cell (RBC) anti- gens,” Alexander Röth, MD, from the department of hematology at University Hospital Essen in Ger- many, and co-authors explained. “Most patients suffer from mild or moderate anemia, with exacerba- tion at cold temperature.” While “drug treatment of chronic CAD has so far been based on cytoreduction, using approach- es derived from the treatment of lymphoma,” potential toxicity pre- cludes their use in older patients. The results from this trial sug- gest that “complement inhibition [via eculizumab] is a well-tolerated alternative in patients ineligible for or not responding to B-cell– directed therapies, when hemolysis is the leading cause of morbidity.” The open-label, prospective, nonrandomized DECADE (Eculi- zumab in cold agglutinin disease) trial evaluated the safety and ef- ficacy of eculizumab in 13 patients: 12 with chronic CAD and one with acute cold agglutinin syndrome. CAD was defined by hemolysis with a cold agglutinin titer ≥64 at 4°C and a monospecific direct antiglobulin test with strong reac- tivity against the complement C3d (a breakdown product of C3b) and negative or weak reactivity against immunoglobulin G. Participants were ≥18 years old (median age = 74 years; range = 64- 80 years) and required treatment because of anemia-related symp- toms or transfusion-dependence. Impact of Eculizumab on Indicators of Hemolysis in Patients With CAD TABLE 2. Laboratory Test Normal Range Lactate dehydrogenase, U/L p Value 572 (534-685) 334 (243-567) 0.022 <22 46.2 (18.2-124.0) 30.0 (19.5-80.6) 0.844 Bilirubin, µmol/L 5.1-20.5 46.0 (34.2-68.4) 43.0 (20.0-61.6) 0.012 Haptoglobin, g/L 0.3-2.0 0.04 (0.03-0.05) 0.03 (0.02-0.05) 0.844 Hemopexin, g/L 0.5-1.2 0.47 (0.18-0.58) 0.85 (0.45-1.09) 0.013 Hemoglobin, g/dL 11.6-16.1 9.35 (8.80-10.80) 10.15 (9.00-11.35) 0.039 22-76 160.2 (99.1-185.5) 111.7 (67.4-142.6) 0.063 Reticulocytes, ×10 9 /L Treatment with alkylating agents, rituximab, human immunoglobu- lins, or plasmapheresis was pro- hibited at least four weeks before screening. Nine patients were transfusion- dependent, with a median of 6 units transfused in the preceding 12 months (range = 2-32 units). Patients received eculizumab 600 mg weekly for four weeks, followed one week later by eculi- zumab 900 mg every other week through 26 weeks of treatment. Eleven patients completed the 26-week treatment phase, at which point they were given the option to continue eculizumab, then monitored through a post- treatment observation phase. Two patients discontinued: One left the study due to clinical suspi- cion of peritonitis and one left because the underlying Raynaud syndrome did not respond to eculizumab. From baseline to the last day of therapy, patients’ median lactate dehydrogenase levels de- creased from 572 U/L to 334 U/L (p=0.0215), the study’s primary endpoint. Seven of 13 patients showed a lactate dehydrogenase decrease ≥250 U/L. In the two patients who elected to continue eculizumab beyond week 26, the lactate de- hydrogenase level remained low (268 U/L and 231 U/L). –ALEXANDER RÖTH, MD ASH Clinical News Week 26 120-247 Free hemoglobin, mg/dL “Our findings suggest that eculizumab was able to control hemolysis in patients with weak, but not in patients with strong, complement activation.” 60 Week 0 The post-treatment observation phase showed increases in hemo- globin and the plasma protein he- mopexin and decreases in bilirubin and reticulocytes – signs of reduced hemolysis: • hemoglobin: 9.35 g/dL (range = 8.80-10.80) to 10.15 g/dL (range = 9.00-11.35; p=0.040) • hemopexin: 0.47 g/L (range = 0.18-0.58) to 0.85 g/L (range = 0.45-1.09; p=0.013) • bilirubin: 46.0 mmol/L (range = 34.2-68.4) to 43.0 mmol/L (range = 20.0-61.6; p=0.012) • reticulocytes: 160.2×10 9 /L (range = 99.1-185.5) to 111.7×10 9 /L (range = 67.4- 142.5; p=0.063) See full results in TABLE 2 . The he- moglobin rise was paralleled by a significant reduction in red blood cell transfusion requirements, the investigators reported, “with three patients maintaining and eight patients acquiring transfu- sion independence (p=0.02).” The median number of units trans- fused was 0 (range = 0-12 units), instead of an expected 2.6 units (range = 0-20.9 units; p=0.06). However, cold-induced circula- tory symptoms, such as acrocya- nosis or Raynaud syndrome, re- mained unaffected by eculizumab. Patients with cold agglutinins with a thermal amplitude of 37°C tended to have less pronounced lactate dehydrogenase responses than patients with cold agglutinins with a narrower thermal ampli- tude (p=0.09 for the comparison of 37°C vs. 4°-30°C). “Suppres- sion of hemolysis caused by cold agglutinins with a wide thermal amplitude may require higher eculizumab doses than used here,” the authors concluded. Thirteen patients experienced a total of 37 adverse events (AEs), including hemorrhoidal hemor- rhage, fatigue, muscle cramps, arterial sclerosis, hypertension, pruritis, and limb pain. Thirteen AEs (occurring in 4 patients) were classified as possibly related to treatment, while one case of severe pneumonia was considered prob- ably related to treatment. Notably, there were no meningococcal infections observed in this trial, despite the recognized increased risk of this toxicity in patients receiving eculizumab. “In CAD, the thermal am- plitude is considered the most relevant measure of disease sever- ity: the higher the temperature at which the antibody can react with the cell, the greater the ability to fix complement and the greater the ensuing damage,” the authors con- cluded. “Our findings suggest that eculizumab was able to control hemolysis in patients with weak, but not in patients with strong, complement activation.” The study is limited by the open-label and non-randomized design, as well as the small patient population. Follow-up was also limited in assessing response duration. Alexion, supported the trial. The authors report financial relation- ships with Roche and Alexion. ● REFERENCE Röth A, Bommer M, Huttmann A, et al. Eculizumab in cold agglutinin disease (DECADE): an open-label, prospective, bicentric, nonrandomized phase 2 trial. Blood Advances. 2018;2:2543-9. December 2018