Predictors for improvement in patient-reported outcomes: post hoc analysis of a phase 3 randomized, open-label study of eculizumab and ravulizumab in complement inhibitor-naive patients with paroxysmal nocturnal hemoglobinuria.

Paroxysmal nocturnal hemoglobinuria (PNH) is characterized by uncontrolled terminal complement activation leading to intravascular hemolysis (IVH), thrombosis, and impairments in quality of life (QoL). The aim of this study was to identify the clinical drivers of improvement in patient-reported outcomes (PROs) in patients with PNH receiving the complement component 5 (C5) inhibitors eculizumab and ravulizumab.This post hoc analysis assessed clinical outcomes and PROs from 246 complement inhibitor-naive patients with PNH enrolled in a phase 3 randomized non-inferiority study that compared the C5 inhibitors ravulizumab and eculizumab (study 301; NCT02946463). The variables of interest were lactate dehydrogenase (LDH) levels, a surrogate measure of IVH, and hemoglobin (Hb) levels. PROs were collected using Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F) and European Organisation for Research and Treatment of Cancer, Quality of Life Questionnaire-Core 30 (EORTC QLQ-C30) to assess fatigue and QoL, respectively.Improvements in absolute mean LDH levels were significantly associated with improvements in mean FACIT-F score (p = 0.0024) and EORTC QLQ-C30 global health (GH) score (p < 0.0001) from baseline to day 183. Improvements in scores were achieved despite a non-significant increase in Hb levels. To understand the interaction between LDH and Hb, a regression analysis was performed: LDH response with Hb improvements was a significant predictor of improvement in fatigue. The independent effect of improved Hb did not significantly affect FACIT-F or EORTC QLQ-C30 GH scores.These findings suggest that LDH levels are an important determinant of fatigue and QoL outcomes in patients with PNH. CTR: NCT02946463, October 27, 2016.

Novel uses of complement inhibitors in myasthenia gravis-Two case reports.

INTRODUCTION/AIMS: Myasthenia gravis (MG) is a rare, life-threatening immune-related adverse effect (irAE) of immune checkpoint inhibitor (ICI) treatment. C5-complement inhibitors are effective treatments for acetylcholine receptor antibody (AChR ab) positive generalized MG. We describe the use of eculizumab/ravulizumab in two patients with MG receiving concomitant pembrolizumab. METHODS: This was a retrospective review of two medical records. RESULTS: Patient 1: An 80-year-old male with recurrent, non-muscle invasive transitional cell carcinoma of the bladder developed ICI-induced AChR ab positive MG (ICI-MG), myositis, and myocarditis 2 weeks after the first dose of pembrolizumab. Myositis responded to corticosteroids. MG responded to eculizumab, followed by ravulizumab. He died of metastatic cancer 8 months later. Patient 2: A 58-year-old male had refractory thymoma-associated AChR ab-positive MG, which responded to eculizumab. He developed metastatic Merkel cell cancer necessitating pembrolizumab. MG remained stable on eculizumab. He had no irAEs for 22 months, with positron emission tomographic resolution of cancer. He then developed mild, indolent retinal vasculitis, which responded to prednisone. Discontinuation of pembrolizumab for 5 months resulted in cancer recurrence; pembrolizumab was resumed with peri-infusion pulse prednisone. MG remained stable and he continues eculizumab. DISCUSSION: In the first patient, eculizumab, followed by ravulizumab, improved ICI-MG. In the second patient, eculizumab treatment may have had a prophylactic effect on the development of ICI-induced irAEs. The effect of complement inhibition on cancer outcomes of ICI therapy is unknown. A possible biologic basis for complement inhibitors in reducing irAEs of ICI, especially in the presence of underlying autoimmune disease, merits evaluation.

Efficacy of ravulizumab in patients with generalized myasthenia gravis by time from diagnosis: A post hoc subgroup analysis of the CHAMPION MG study.

INTRODUCTION/AIMS: The CHAMPION MG study demonstrated that ravulizumab significantly improved Myasthenia Gravis-Activities of Daily Living (MG-ADL) and Quantitative Myasthenia Gravis (QMG) total scores versus placebo in adults with acetylcholine receptor antibody-positive generalized myasthenia gravis (AChR+ gMG). This post hoc analysis aimed to assess these outcomes by time from MG diagnosis. METHODS: Changes from baseline to week 26 in MG-ADL and QMG total scores were analyzed by time from MG diagnosis to study entry (≤2 vs. >2 years). Within each subgroup, least-squares (LS) mean changes for ravulizumab and placebo were compared using mixed models for repeated measures. RESULTS: In ravulizumab-treated patients, differences in LS mean (standard error of the mean) changes from baseline to week 26 were not statistically significant in the ≤2-years subgroup versus the >2-years subgroup for MG-ADL (-4.3 [0.70] vs. -2.9 [0.37]; p = .0511) or QMG (-4.3 [0.94] vs. -2.5 [0.50]; p = .0822) scores. No clear trends were observed in the placebo group. LS mean changes from baseline were significantly greater for ravulizumab versus placebo in both the ≤2 and >2 years from diagnosis subgroups for MG-ADL and QMG scores (all p < .05). The difference in treatment effect between the ≤2-years and >2-years subgroups was not statistically significant. No clinically meaningful between-subgroup differences in treatment-emergent adverse events were observed in ravulizumab-treated patients. DISCUSSION: Ravulizumab treatment improved clinical outcomes for patients with AChR+ gMG regardless of time from diagnosis. A numerical trend was observed favoring greater treatment effect with earlier versus later treatment after diagnosis. Further studies are required for confirmation.

Complement-mediated thrombotic microangiopathy treated with anticomplement protein 5 therapy, a retrospective study.

BACKGROUND: Complement-mediated thrombotic microangiopathy (CM-TMA), also called atypical hemolytic uremic syndrome (aHUS), is a difficult-to-diagnose rare disease that carries severe morbidity and mortality. Anti-C5 monoclonal antibodies (aC5-mab) are standard treatments, but large studies and long-term data are scarce. Here, we report our single institution experience to augment the knowledge of CM-TMA treated with aC5-mab therapy. METHODS: We aimed to assess the short and long-term effects of aC5-mab in patients diagnosed with CM-TMA treated outside of a clinical trial. This was a retrospective study. We included all patients diagnosed with CM-TMA and treated with aC5-mab at our institution. There were no exclusion criteria. Endpoints included complete TMA response (CR) defined as normalization of hematological parameters and ≥25% improvement in serum creatinine (Cr) from baseline in patients with renal disease, relapse defined as losing the previously achieved CR, morbidity, adverse events, and survival. RESULTS: We found 28 patients with CM-TMA treated with aC5-mab. The median age was 50 years. Baseline laboratories: platelet counts 93 × 109 /L, hemoglobin 8.6 g/dL, lactate dehydrogenase 1326 U/L, serum Cr 4.7 mg/dL, and estimated glomerular filtration rate 19 mL/min. One individual was on renal replacement therapy (RRT) and 10 initiated RRT within 5 days of the first dose of aC5-mab. Genetic variants associated with CM-TMA included mutations in C3, CFB, CFH, CFHR1/3, CFI, and MCP. The mean duration of hospitalization was 24 days. The median time to initiation of aC5-mab was 10 days. Sixteen subjects received RRT. At the time of hospital discharge, 27 were alive, 14 remained on RRT, and 4 had a CR. At 6 months, 23 patients were alive, 18 continued aC5-mab, 8 remained on RRT, and 9 had a CR. At the last follow-up visit past 6 months, 20 were alive, 14 continued aC5-mab, 5 remained on RRT, 12 had a CR, and 1 was lost to follow-up. CONCLUSIONS: Our study provides real-world experience and insight into the long-term outcomes of CM-TMA treated with aC5-mab. Our findings validate that CM-TMA is an aggressive disease with significant morbidity and mortality, and confirm that aC5-mab is a relatively effective therapy for CM-TMA. Our study adds practical, real-world experience to the literature, but future research remains imperative.

Clinical efficacy and safety of switching from eculizumab to ravulizumab in adult patients with aHUS- real-world data.

BACKGROUND: The complement factor 5 (C5)-inhibitor eculizumab has been established as standard-of-care for the treatment of atypical hemolytic uremic syndrome (aHUS). In 2021, the long-acting C5-inhibitor ravulizumab was approved, extending intervals of intravenous treatment from two to eight weeks resulting in improvement of quality of life for patients and lowering direct and indirect therapy associated costs. METHODS: This multicenter, retrospective data analysis of 32 adult patients with aHUS (including 10 kidney transplant recipients) treated with eculizumab for at least three months and switched to ravulizumab aims to evaluate the safety and efficacy of switching medication in the real-world setting. Hematologic parameters, kidney function, concurrent therapy and aHUS associated events were evaluated three months before and until up to 12 months after switching to ravulizumab. RESULTS: Mean age (range) at ravulizumab initiation was 41 years (19-78 years) and 59% of the patients were female. Genetic analysis was available for all patients with 72% showing a pathogenic variant. Median time (range) on eculizumab before switching was 20 months (3-120 months). No new events of TMA or worsening of renal function were reported during up to 12 months of follow-up during ravulizumab treatment. CONCLUSIONS: This is the largest, non-industry derived, multi-center retrospective analysis of adult patients with aHUS switching C5-inhibitor treatment from eculizumab to ravulizumab in the real-world setting. Switching to ravulizumab was safe and efficient resulting in sustained hematological stability and preservation of renal function.

Ravulizumab facilitates reduced burden of vascular access, a major benefit in paediatric atypical haemolytic uraemic syndrome.

BACKGROUND: Atypical haemolytic uraemic syndrome (aHUS) is a rare thrombotic microangiopathy resulting from dysregulation of the alternative complement pathway, leading to multi-organ dysfunction and chronic kidney disease. Eculizumab is an anti-C5 monoclonal antibody therapy that has significantly improved aHUS disease control and patient outcomes, however it requires fortnightly intravenous dosing. This often necessitates long term central access and a high hospital attendance burden. Ravulizumab is a novel, next-generation anti-C5 monoclonal antibody engineered from eculizumab to reduce endosomal degradation of the antibody, increasing the dosing interval up to 8 weeks. CASE SERIES: In this retrospective case series we present the transition of three children with aHUS from eculizumab to ravulizumab from a single tertiary paediatric nephrology service. All patients underwent genomic and immunological work up for aHUS, with no cause found. After stabilisation with eculizumab, two patients developed macrovascular thrombotic complications associated with indwelling central vascular catheters, ultimately leading to central access failure. All patients were transitioned from eculizumab to ravulizumab without relapse of aHUS. One patient successfully underwent deceased donor kidney transplantation with ravulizumab for complement inhibition. All patients have transitioned to peripheral access for infusions given the reduced frequency of dosing, maintaining good control of aHUS for 2-4 years. CONCLUSION: Ravulizumab permits sufficiently reduced frequency of infusion to allow for administration by peripheral cannulation - removing the risks of long term central vascular access often required to deliver eculizumab to paediatric patients.

Periungual pyogenic granulomas after ravulizumab therapy in a child with acute myelomonocytic leukemia treated with hematopoietic stem cell transplant.

Development of periungual pyogenic granulomas (pPGs) has been associated with several systemic treatments, including retinoids, taxanes, epidermal growth factor receptor inhibitors, and vascular endothelial growth factor inhibitors. We present the case of an 8-year-old girl with a personal history of acute myelomonocytic leukemia treated with a haploidentical hematopoietic stem cell transplant who developed pPGs 2 months after starting ravulizumab. Ravulizumab is a monoclonal antibody directed against C5 protein. No previous reports of pPGs development have been described with ravulizumab.

Safety Profile of Monoclonal Antibodies and Subsequent Drug Developments in the Treatment of Paroxysmal Nocturnal Hemoglobinuria.

Paroxysmal nocturnal hemoglobinuria (PNH) is a clonal stem cell disease characterized by intravascular hemolysis due to the targeting of affected red blood cells by the complement system. Eculizumab and ravulizumab are two monoclonal antibodies that inhibit the complement system's components and have been shown to significantly improve survival and quality of life. This review describes the role of these monoclonal antibodies in the treatment of PNH with an emphasis on their safety profile. The challenges in the use of these drugs and new drugs in various stages of drug development are also described, which may be helpful in addressing some of these challenges.

Dose optimalization of subcutaneous ravulizumab is predicted to yield significant savings and to improve patient friendliness.

Ravulizumab is an expensive complement C5-inhibitor for the treatment of paroxysmal nocturnal haemoglobinuria. Recently, a subcutaneous formulation has entered the market, for which the approved dosing regimen results in supratherapeutic ravulizumab concentrations in the majority of patients in the registration studies. Therefore, we explored alternative dosing regimens in silico based on the registration data of the manufacturer. Extending the interval from 1 to 2 weeks or individualized dosing based on therapeutic drug monitoring resulted in therapeutic ravulizumab concentrations and comparable predicted efficacy in terms of lactate dehydrogenase normalization, with dose reductions up to 64%. We here show that with an individualized dose, a substantial dose reduction for subcutaneous ravulizumab might be possible with improved patient-friendliness.

[Japanese patient preferences between ravulizumab and eculizumab for the treatment of paroxysmal nocturnal hemoglobinuria].

Ravulizumab is the first long-acting complement inhibitor approved for paroxysmal nocturnal hemoglobinuria (PNH) treatment. We evaluated patient preference for ravulizumab or eculizumab among Japanese adults with PNH. The ALXN1210-PNH-301 (NCT02946463) and ALXN1210-PNH-302 (NCT03056040) studies included 23 Japanese adults who are enrolled in complement inhibitor treatment-naive and eculizumab (≥6 months) treatment. Patient preference was assessed using the PNH-specific patient preference questionnaire (PNH-PPQ©). Most patients preferred ravulizumab (19/23, 82.6%), none preferred eculizumab, and four (17.4%) reported no preference (χ2 test, p<0.005). The preference for ravulizumab was driven by its lower infusion frequency (every 8 weeks) compared with eculizumab (every 2 weeks). The included Japanese patients with PNH preferred ravulizumab because of its reduced infusion frequency, which increases activity planning ability, treatment convenience, and overall quality of life, as compared with eculizumab. These data provide useful insight into patient perspectives and may aid decision-making for PNH treatment.

The burden of illness in patients with paroxysmal nocturnal hemoglobinuria receiving treatment with the C5-inhibitors eculizumab or ravulizumab: results from a US patient survey.

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare and life-threatening disease with symptoms of hemolysis and thrombosis. Current therapies for this complement-mediated disease rely predominantly on inhibition of the C5 complement protein. However, data on treatment responses and quality of life in C5-inhibitor (C5i)-treated PNH patients are scarce. The objective of this study was to determine C5i treatment effects on clinical parameters, PNH symptoms, quality of life, and resource use for PNH patients. This cross-sectional study surveyed 122 individuals in the USA receiving treatment for PNH with C5-targeted monoclonal antibodies, eculizumab (ECU) or ravulizumab (RAV). Despite most patients receiving C5i therapy for ≥ 3 months (ECU 100%, n = 35; RAV 95.4%, n = 83), many patients remained anemic with hemoglobin levels ≤ 12 g/dL in 87.5% (n = 28/32) and 82.9% (n = 68/82) of ECU and RAV recipients, respectively. A majority of patients on ECU (88.6%; n = 31/35) and RAV (74.7%; n = 65/87) reported fatigue symptoms. Among PNH patients receiving C5i therapy for ≥ 12 months, some still reported thrombotic events (ECU, 10.0%, n = 1/10; RAV, 23.5%, n = 4/17) and required transfusions within the past year (ECU, 52.2%, n = 12/23; RAV, 22.6%, n = 7/31). Other patient-reported PNH symptoms included breakthrough hemolysis, shortness of breath, and headaches. Patients reported scores below the average population norms on the Functional Assessment of Chronic Illness Therapy (FACIT)-Fatigue and European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30) scales. Overall, this study found that PNH patients receiving ECU or RAV therapy demonstrated a significant burden of illness, highlighting the need for improved PNH therapies.

Composite endpoint to evaluate complement inhibition therapy in patients with paroxysmal nocturnal hemoglobinuria.

This study developed and explored a novel composite endpoint to assess the overall impact that treatment can have on patients living with paroxysmal nocturnal hemoglobinuria (PNH). Candidate composite endpoint variables were selected by a group of experts and included: lactate dehydrogenase levels as a measure of intravascular hemolysis; complete terminal complement inhibition; absence of major adverse vascular events, including thrombosis; absence of any adverse events leading to death or discontinuation of study treatment; transfusion avoidance; and improvements in fatigue-related quality of life as determined by the Functional Assessment of Chronic Illness Therapy (FACIT)-Fatigue score. From these variables, a novel composite endpoint was constructed and explored using data collected in the ravulizumab PNH Study 301 (NCT02946463). Thresholds were defined and reported for each candidate variable. Five of the six candidate variables were included in the final composite endpoint; the FACIT-Fatigue score was excluded. Composite endpoint criterion was defined as patients meeting all five selected individual component thresholds. All patients in the ravulizumab arm achieved complete terminal complement inhibition and a reduction in lactate dehydrogenase levels; 51.2% and 41.3% of patients in the ravulizumab arm and eculizumab arm, respectively, achieved all composite endpoint component thresholds (treatment difference: 9.4%; 95% confidence interval: -3.0, 21.5). The composite endpoint provided a single and simultaneous measurement of overall benefit for patients receiving treatment for PNH. Use of the composite endpoint in future PNH research is recommended to determine clinical benefit, and its use in health technology assessments should be evaluated.

Long-term safety and efficacy of ravulizumab in patients with paroxysmal nocturnal hemoglobinuria: 2-year results from two pivotal phase 3 studies.

OBJECTIVES: The complement component 5 (C5) inhibitor ravulizumab demonstrated non-inferiority to eculizumab following 26 weeks of treatment in complement inhibitor-naïve and complement inhibitor-experienced patients with paroxysmal nocturnal hemoglobinuria (PNH; studies 301 and 302, respectively). This study aims to describe the results of both studies from 27 weeks to 2 years. METHODS: Patients (N = 441) continued to receive ravulizumab throughout the extension period. Efficacy endpoints included lactate dehydrogenase (LDH) normalization, transfusion avoidance and fatigue score (FACIT-F). Safety analyses were also performed. RESULTS: From 27 weeks to 2 years, improvements in LDH levels were maintained in both study populations. Transfusion avoidance was maintained in 81.9% (study 301) and 85.6% (study 302) of patients, and FACIT-F scores remained stable. Ravulizumab was well tolerated, and the incidence of adverse events (AEs) were similar between patients of both studies. Incidence of serious AEs deemed related to ravulizumab treatment was low (<3%). CONCLUSIONS: This study reports, to date, the longest period of follow-up in over 400 patients with PNH treated with ravulizumab (662 patient-years). Long-term, ravulizumab demonstrated durable efficacy and was well tolerated, highlighting the importance of C5 inhibitors as the mainstay of PNH treatment.

The burden of illness of patients with paroxysmal nocturnal haemoglobinuria receiving C5 inhibitors in France, Germany and the United Kingdom: Patient-reported insights on symptoms and quality of life.

OBJECTIVES: To assess the clinical, humanistic and economic burden of paroxysmal nocturnal haemoglobinuria (PNH) among C5 inhibitor (C5i)-treated patients with PNH. METHODS: This was a web-based, cross-sectional survey (01FEB2021-31MAR2021) of adults with PNH treated with eculizumab (France, Germany, United Kingdom) or ravulizumab (Germany). Self-reported outcomes included: patient characteristics; patient-reported symptoms; and standardised patient-reported outcomes (e.g. Functional Assessment of Chronic Illness Therapy [FACIT]-Fatigue, European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 [EORTC QLQ-C30]). RESULTS: Among 71 included patients, 98.6% were C5i-treated for ≥3 months (88.7% ≥12 months); among those with self-reported haemoglobin (Hb) levels (n = 63), most (85.7%) were anaemic (defined as ≤12.0 g/dL). Fatigue was the most common symptom at both diagnosis (73.2%) and survey time (63.4%); there were no statistically significant differences in symptom prevalence between treatment subgroups (eculizumab vs. ravulizumab). Total FACIT-Fatigue and EORTC QLQ-C30 scores were substantially lower than European general population references, but there were no statistically significant differences between treatment subgroups. Hb-level subgroups (<10.5 g/dL vs. ≥10.5 d/dL) followed similar trends for all measures, with few significant subgroup differences. CONCLUSIONS: Results suggest that there remains a considerable burden and unmet need among C5i-treated patients with PNH that requires improved therapies.

Ravulizumab 100 mg/mL formulation reduces infusion time and frequency, improving the patient and caregiver experience in the treatment of atypical haemolytic uraemic syndrome.

WHAT IS KNOWN AND OBJECTIVE: The C5 inhibitor eculizumab is the standard of care for treatment of atypical haemolytic uraemic syndrome (aHUS). Ravulizumab, a next-generation C5 inhibitor, was engineered to have a longer terminal half-life than eculizumab. We describe practical benefits of the advanced ravulizumab 100 mg/mL formulation. COMMENT: Use of ravulizumab results in fewer maintenance infusions per year (25%-50%) compared with eculizumab. Maintenance infusion time of ravulizumab 100 mg/mL is 2-4 times shorter than ravulizumab 10 mg/mL in all weight cohorts and approximately half that of eculizumab for patients weighing <40 kg. Ravulizumab 100 mg/mL requires fewer vials annually than eculizumab in most weight cohorts. WHAT IS NEW AND CONCLUSION: With ravulizumab 100 mg/mL, patients and caregivers experience fewer infusions per year and decreased annual infusion times, improving infusion experience. Infusion centres can expect corresponding decreases in resource utilization.

[Perioperative management of laparoscopic cholecystectomy in a patient with paroxysmal nocturnal haemoglobinuria undergoing ravulizumab treatment].

Paroxysmal nocturnal hemoglobinuria (PNH) is characterized by hemolysis, thrombosis, and bone marrow failure. Infection, pregnancy, and surgical operation have the potential to evoke severe episodes of hemolysis and thrombosis. Therefore, the use of an antibody agent against complement component 5 (C5), eculizumab, one day before the operation is recommended. Ravulizumab is a newly approved long-acting antibody agent against C5. Thus, little is known about perioperative management with ravulizumab. We experienced a 43-year-old female patient who safely underwent laparoscopic cholecystectomy under ravulizumab treatment for PNH. Ravulizumab was administered one day before the operation. Laparoscopic cholecystectomy for cholelithiasis was performed under intravenous anesthesia, intermittent air compression of the lower extremities, and low pneumoperitoneum pressure. Additionally, heparin was administered, and the patient left the sickbed early without significant postoperative complications. Like eculizumab, complement inhibition by ravulizumab is also considered effective in the perioperative management of patients with PNH. However, close cooperation with surgeons and anesthesiologists and careful management based on clinical symptoms and laboratory data such as LDH, CH50, and D-dimer are essential.

Selected severe „haematological“ syndromes in adult intensive care patients.

Haemophagocytic syndrome, diffuse alveolar haemorrhage, catastrophic antiphospholipid syndrome and various types of thrombotic microangiopathies are rare conditions with significant morbidity and mortality. A common feature is late diagnosis, which can affect the success of treatment. The aim of this review article is to summarize the basic diagnostic and therapeutic steps of the present subpopulation of critically ill patients.

The long-acting C5 inhibitor, ravulizumab, is effective and safe in pediatric patients with atypical hemolytic uremic syndrome naïve to complement inhibitor treatment.

Ravulizumab, a long-acting complement C5 inhibitor engineered from eculizumab, allows extending maintenance dosing from every 2-3 weeks to every 4-8 weeks depending on bodyweight. Here, we evaluated the efficacy and safety of ravulizumab in complement inhibitor-naïve children (under 18 years) with atypical hemolytic uremic syndrome. In this phase III, single-arm trial, ravulizumab was administered every eight weeks in patients 20 kg and over, and four weeks in patients under 20 kg. The primary endpoint was a complete thrombotic microangiopathy response (normalization of platelet count and lactate dehydrogenase, and a 25% or more improvement in serum creatinine) through 26 weeks. Secondary endpoints included change in hematologic parameters and kidney function. 18 patients with a median age of 5.2 years were evaluated. At baseline, symptoms of atypical hemolytic uremic syndrome outside the kidney were present in 72.2% of patients and 38.9% had been in intensive care. Baseline estimated glomerular filtration rate was 22 mL/min/1.73 m2. By week 26, 77.8% of patients achieved a complete thrombotic microangiopathy response; 94.4%, 88.9% and 83.3% of patients achieved platelet normalization, lactate dehydrogenase normalization and a 25% or more improvement in serum creatinine, respectively. By week 50, 94.4% patients had achieved a complete thrombotic microangiopathy response. Median improvement in platelet count was 246 and 213 x109/L through week 26 and week 50, respectively. The median increase above baseline in estimated glomerular filtration rate was 80 and 94 mL/min/1.73m2 through week 26 and week 50, respectively. No unexpected adverse events, deaths, or meningococcal infections occurred. Thus, ravulizumab rapidly improved hematologic and kidney parameters with no unexpected safety concerns in complement inhibitor-naïve children with atypical hemolytic uremic syndrome.

The potential of individualized dosing of ravulizumab to improve patient-friendliness of paroxysmal nocturnal haemoglobinuria treatment at reduced costs.

Ravulizumab is a very expensive complement C5-inhibitor for the treatment of paroxysmal nocturnal haemoglobinuria, with a fixed-dosing interval of 8 weeks. For lifelong treatment, a cost-effective and patient-friendly dosing strategy is preferred. We therefore explored alternative ravulizumab dosing regimens in silico based on the thorough dose-finding studies of the manufacturer. Extending the interval to 10 weeks or individually extending the interval to a mean of 12.8 weeks based on pharmacokinetic monitoring resulted in noninferior efficacy in terms of lactate dehydrogenase normalization, with drug cost savings up to 37%. We here show the potential of individualized ravulizumab dosing to improve patient-friendliness at reduced costs.

New Therapeutic Targets and Treatment Options for Thrombotic Microangiopathy: Caplacizumab and Ravulizumab.

OBJECTIVE: To review the efficacy and safety of caplacizumab and ravulizumab for thrombotic microangiopathy. DATA SOURCES: A literature search from January 2011 to May 2020 was performed using the key terms caplacizumab (or ALX-0681), ravulizumab (or ALXN1210), atypical hemolytic uremic syndrome (aHUS), acquired thrombotic thrombocytopenic purpura (aTTP), and thrombotic microangiopathy. STUDY SELECTION AND DATA EXTRACTION: Relevant clinical trials and articles in the English language were identified and reviewed. DATA SYNTHESIS: aTTP and aHUS are syndromes of thrombotic microangiopathy manifested by excessive platelet aggregation and endothelial cell destruction, with subsequent thrombocytopenia, hemolysis, and multiorgan failure. Current standard therapy for aTTP is therapeutic plasma exchange (TPE) to remove von Willebrand factor (vWF) multimers and anti-ADAMTS13 autoantibodies. As an adjunctive therapy to TPE, caplacizumab inhibits binding of vWF to platelets and prevents new microthrombi formation. It reduces thromboembolic event rate and days of TPE and delays relapse. Headache and epistaxis were the most common adverse events. aHUS develops because of dysregulation of the alternative complement pathway, followed by constitutive activation of complement components that causes thrombosis and end-organ damage. Short-term initial evaluation with ravulizumab, a long-acting complement inhibitor, demonstrates rapid hematological and renal improvement, with sustained complement inhibition and tolerable adverse effects. RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE: This review describes the pharmacology, pharmacokinetics, cost consideration, and clinical studies for caplacizumab and ravulizumab for thrombotic microangiopathy. Place of therapy is also discussed. CONCLUSION: Targeted therapies with caplacizumab and ravulizumab are expected to reduce the burden of exacerbation, refractory disease, recurrence, and possibly death for thrombotic microangiopathy.