Phase 3 randomized COMMODORE 1 trial: Crovalimab versus eculizumab in complement inhibitor-experienced patients with paroxysmal nocturnal hemoglobinuria.

Crovalimab, a novel C5 inhibitor, allows for low-volume, every-4- week, subcutaneous self-administration. COMMODORE 1 (NCT04432584) is a phase 3, global, randomized trial evaluating crovalimab versus eculizumab in C5 inhibitor-experienced patients with paroxysmal nocturnal hemoglobinuria (PNH). Adults with lactate dehydrogenase ≤1.5 × upper limit of normal and receiving approved eculizumab doses for ≥24 weeks were randomized 1:1 to receive crovalimab (weight-based tiered dosing) or continue eculizumab. The original primary study objective was efficacy; however, given the evolving treatment landscape, target recruitment was not met, and all efficacy endpoints became exploratory, with safety as the new primary objective. Exploratory efficacy endpoints included transfusion avoidance, hemolysis control, breakthrough hemolysis, hemoglobin stabilization, FACIT-Fatigue score, and patient preference (crovalimab vs. eculizumab). Eighty-nine patients were randomized (45 to crovalimab; 44 to eculizumab). During the 24-week primary treatment period, adverse events (AEs) occurred in 77% of patients receiving crovalimab and 67% receiving eculizumab. No AEs led to treatment withdrawal or death, and no meningococcal infections occurred. 16% of crovalimab-treated patients had transient immune complex reactions (also known as Type III hypersensitivity events), an expected risk when switching between C5 inhibitors that bind to different C5 epitopes; most were mild/moderate and all resolved without treatment modification. Crovalimab-treated patients had sustained terminal complement activity inhibition, maintained disease control, and 85% preferred crovalimab over eculizumab. Together with phase 3 COMMODORE 2 results in complement inhibitor-naive patients, these data support crovalimab's favorable benefit-risk profile. Crovalimab is a new C5 inhibitor for PNH that is potentially less burdensome than existing therapies for this lifelong disease.

Phase 3 Study of Subcutaneous Versus Intravenous Ravulizumab in Eculizumab-Experienced Adult Patients with PNH: Primary Analysis and 1-Year Follow-Up.

INTRODUCTION: This study compared the pharmacokinetics (PK) of the ravulizumab on-body delivery system for subcutaneous (SUBQ) administration with intravenous (IV) ravulizumab in eculizumab-experienced patients with paroxysmal nocturnal hemoglobinuria (PNH). METHODS: Patients with PNH received SUBQ ravulizumab (n = 90) or IV ravulizumab (n = 46) during the 10-week randomized treatment period; all patients then received SUBQ ravulizumab during an extension period (< 172 weeks; data cutoff 1 year). Primary endpoint was day 71 serum ravulizumab trough concentration (Ctrough). Secondary endpoints were ravulizumab Ctrough and free C5 over time. Efficacy endpoints included change in lactate dehydrogenase (LDH), breakthrough hemolysis (BTH), transfusion avoidance, stabilized hemoglobin, and Treatment Administration Satisfaction Questionnaire (TASQ) score. Safety, including adverse events (AEs) and adverse device effects (ADEs), was assessed until data cutoff. RESULTS: SUBQ ravulizumab demonstrated PK non-inferiority with IV ravulizumab (day 71 SUBQ/IV geometric least-squares means ratio 1.257 [90% confidence interval 1.160-1.361; p < 0.0001]). Through 1 year of SUBQ administration, ravulizumab Ctrough values were > 175 µg/mL (PK threshold) and free C5 < 0.5 µg/mL (PD threshold). Efficacy endpoints remained stable: mean (standard deviation, SD) LDH percentage change was 0.9% (20.5%); BTH events, 5/128 patients (3.9%); 83.6% achieved transfusion avoidance; 79.7% achieved stabilized hemoglobin. Total TASQ score showed improved satisfaction with SUBQ ravulizumab compared with IV eculizumab (mean [SD] change at SUBQ day 351, - 69.3 [80.1]). The most common AEs during SUBQ treatment (excluding ADEs) were headache (14.1%), COVID-19 (14.1%), and pyrexia (10.9%); the most common ADE unrelated to a device product issue was injection site reaction (4.7%). Although many patients had ≥ 1 device issue-related ADE, full SUBQ dose administration was achieved in 99.9% of attempts. CONCLUSIONS: SUBQ ravulizumab provides an additional treatment choice for patients with PNH. Patients may switch to SUBQ ravulizumab from IV eculizumab or ravulizumab without loss of efficacy. TRIAL REGISTRATION: NCT03748823.

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare blood disorder characterized by the destruction of red blood cells (hemolysis) within blood vessels. In addition to hemolysis, patients with PNH are susceptible to life-threatening blood clots (thromboses). Eculizumab and ravulizumab are types of treatments for PNH, called C5 inhibitors. In the blood, these treatments bind to C5 protein and prevent the destruction of red blood cells, reducing the symptoms and complications of PNH. Both treatments are approved for use via intravenous (through the vein) administration. Ravulizumab is also approved in the USA for use via subcutaneous (under the skin) administration. This study compared subcutaneous ravulizumab with intravenous ravulizumab in patients with PNH who had previously been treated with eculizumab. During the initial treatment period of 71 days, 90 patients received subcutaneous ravulizumab and 46 received intravenous ravulizumab. Following this period, all patients received subcutaneous ravulizumab. At day 71, the amount of ravulizumab in the blood of patients taking subcutaneous ravulizumab was no less than in patients taking intravenous ravulizumab and was maintained over 1 year of treatment. Efficacy measures (how well it works) remained stable in patients taking subcutaneous ravulizumab for 1 year and side effects were comparable with those of intravenous ravulizumab. Patients reported more satisfaction with subcutaneous ravulizumab than intravenous eculizumab, as assessed by the Treatment Administration Satisfaction Questionnaire. This study showed that patients with PNH can switch from intravenous eculizumab or ravulizumab to subcutaneous ravulizumab without loss of efficacy. Subcutaneous ravulizumab provides an additional treatment choice for patients with PNH.

Clinical course and disease burden in patients with paroxysmal nocturnal hemoglobinuria by hemolytic status.

Disease characteristics of patients enrolled in the International PNH Registry were assessed during two follow-up periods based on hemolytic status while untreated with eculizumab: Non-hemolytic cohort: follow-up time defined as time from disease start until last reported untreated lactate dehydrogenase (LDH) value <1.5×upper limit normal (ULN); Hemolytic cohort: follow-up time defined as time from LDH ≥1.5×ULN at or post-disease start, to most recent untreated follow-up. A total of 1012 patients met criteria for the Non-hemolytic cohort and 1565 patients for the Hemolytic cohort; median (min, max) years of follow-up were 2.2 (0.0, 54.2) and 1.2 (0.0, 37.2) years, respectively. Annual rate of thrombotic events (TEs) was lower in the Non-hemolytic than Hemolytic cohort (0.01 events/person-year vs. 0.03 events/person-year; p<0.001). Mortality was lower in the Non-hemolytic cohort than the Hemolytic cohort (0.1% (1 death) vs. 1.8% (22 deaths); p<0.001). While elevated risks for TEs were observed in patients with hemolysis, many TEs were also observed in patients without hemolysis. As thrombosis is the leading cause of mortality in patients with PNH, this real-world analysis highlights the importance of awareness and monitoring for TEs in patients with PNH regardless of hemolytic status.

Atypical Hemolytic Uremic Syndrome: Differential Diagnosis from TTP/HUS and Management.

Atypical hemolytic uremic syndrome (aHUS) is a rare form of thrombotic microangiopathy (TMA). It has an unfavorable outcome with death rates as high as 25% during the acute phase and up to 50% of cases progressing to end-stage renal failure. Uncontrolled complement activation through the alternative pathway is thought to be the main underlying pathopysiology of aHUS and corresponds to all the deleterious findings of the disease. Thrombotic thrombocytopenic purpura (TTP) and Shiga toxin-associated HUS are the 2 other important TMA diseases. Although differentiating HUS from TTP is relatively easy in children with a preceding diarrheal illness or invasive S. pneumoniae, differentiating aHUS from TTP or other microangiopathic disorders can present a major diagnostic challenge in adults. ADAMTS13 analysis is currently the most informative diagnostic test for differentiating TTP, congenital TTP, and aHUS. Today empiric plasma therapy still is recommended by expert opinion to be used as early as possible in any patient with symptoms of aHUS. The overall treatment goal remains restoration of a physiological balance between activation and control of the alternative complement pathway. So it is a reasonable approach to block the terminal complement complex with eculizumab in order to prevent further organ injury and increase the likelihood organ recovery. Persistence of hemolysis or lack of improvement of renal function after 3-5 daily plasmaphereses have to be regarded as the major criteria for uncontrolled TMA even if platelet count has normalized and as an indication to switch the treatment to eculizumab. Eculizumab has changed the future perspectives of patients with aHUS and both the FDA and the EMA have approved it as life-long treatment. However, there are still some unresolved issues about the follow-up such as the optimal duration of eculizumab treatment and whether it can be stopped or how to stop the therapy.

Expression of adducin genes during erythropoiesis: a novel erythroid promoter for ADD2.

OBJECTIVE: The first objective of this study was to examine the differences in levels of adducin (ADD1, ADD2, ADD3) mRNA expression during human erythropoiesis. The second objective was to determine whether the rapid induction of ADD2 expression could be attributed to a novel erythroid-specific promoter. METHODS: Expression of mRNA was quantified using real-time RT-PCR. Primary erythroid precursors were isolated from normal human bone marrow using fluorescence-activated cell sorting. Two model systems were compared: CD34(+) hematopoietic stem cells induced to differentiate with erythropoietin and HEL cells induced to differentiate with hemin. 5'RACE analysis was performed using primary human erythroblasts as starting material. RESULTS: All three adducin genes showed different patterns of expression during erythropoietic differentiation of cultured CD34(+) stem cells. Levels of ADD3 mRNA were higher than levels of ADD2 mRNA at early stages of erythropoiesis. Expression of ADD2 was induced to very high levels (100 times baseline) in erythropoietin-stimulated cultures. 5'RACE analysis identified a novel starting exon and putative erythroid promoter for ADD2. CONCLUSION: These results suggest that expression of each adducin gene is regulated in a gene-specific manner during erythropoiesis. The early expression of ADD3 suggests that it may have a role in erythroblasts but is replaced by ADD2 in later stages of erythropoiesis. The very high levels of expression of ADD2 suggest that its promoter may be useful for directing erythroid-specific gene expression.

Coexistence of homozygous factor V Leiden mutation and antiphospholipid antibodies in two patients presented with Budd-Chiari syndrome.

Two female patients are reported, who presented with Budd-Chiari syndrome (hepatic vein thrombosis), and were found to have both, antiphospholipid antibodies and homozygous factor V Leiden mutation. Both patients also had recurrent fetal losses, as well as splenic and portal vein thrombosis. The coexistence of homozygous factor V Leiden mutation and antiphospholipid antibodies in patients with Budd-Chiari syndrome is extremely rare. The interaction of antiphospholipid antibodies and factor V Leiden mutation in the pathogenesis of antiphospholipid syndrome and their contribution to Budd-Chiari syndrome are discussed.