[Translated article] Pharmacokinetics of eculizumab in adult and pediatric patients with atypical hemolytic uremic syndrome and C3 glomerulopathy

OBJECTIVE

The objective of the study was to analyze and describe the concentrations of eculizumab and the complement blockade in patients with atypical hemolytic uremic syndrome (aHUS) and C3 glomerulopathy, and to define a therapeutic margin where there is a high probability of achieving therapeutic efficacy.

METHODS

Observational, ambispective, and multicenter study that included adult and pediatric patients diagnosed with aHUS and C3 glomerulopathy from September 2020 to October 2022 in 5 hospitals in Spain. Eculizumab was administered at the doses recommended by the data sheet according to the European Medicines Agency (EMA). Pre- and post-dose concentrations of eculizumab were determined, as well as blockade of the classical complement pathway (CH50). Sociodemographic and clinical data were collected, and pharmacokinetic parameters were calculated. To establish the cut-off point for eculizumab concentrations that predicted complement blockade, Receiver Operating Characteristic (ROC) curve analysis was performed. Lastly, the Kruskal-Wallis test was used to contrast the differences in different parameters according to eculizumab concentrations.

RESULTS

Twenty-five patients were included, 19 adults (76.0%) and 6 pediatrics (24.0%), with median ages of 43.4 (interquartile range (IQR) 35.7-48.8) and 10.1 (IQR 9.6-11.3) years, respectively. Of these, 22 (88.0%) patients were diagnosed with aHUS and 3 (12.0%) with C3 glomerulopathy. A total of 111 eculizumab concentrations were determined. Mean pre- and post-dose concentration values detected during the maintenance phase were 243.8 (SD 240.6) μg/mL and 747.4 (standard deviation (SD) 444.3) μg/mL, respectively. Increased complement blockade was observed at higher pre-dose concentrations (P = .002) and decreased serum creatinine at both higher pre- and post-dose concentrations (P = .001 and P = .017, respectively). Using ROC curves, it was determined that a pre-dose concentration >149.0 μg/mL was optimal to achieve complement blockade, with an AUC of 0.87 (0.78-0.95). Finally, high inter-individual (48.9% variation coefficient (CV)) with low intra-individual variabilities (11.9% CV) in eculizumab clearance were observed.

CONCLUSIONS

The present study reports supratherapeutic concentrations of eculizumab in patients with aHUS, and defines higher concentrations than those described in the data sheet to achieve blockade, thus encouraging the personalization of treatment with eculizumab.

Pharmacokinetics of eculizumab in adult and pediatric patients with atypical hemolytic uremic syndrome and C3 glomerulopathy

OBJECTIVE

The objective of the study was to analyze and describe the concentrations of eculizumab and the complement blockade in patients with atypical hemolytic uremic syndrome (aHUS) and C3 glomerulopathy, and to define a therapeutic margin where there is a high probability of achieving therapeutic efficacy.

METHODS

Observational, ambispective and multicenter study that included adult and pediatric patients diagnosed with aHUS and C3 glomerulopathy from September 2020 to October 2022 in five hospitals in Spain. Eculizumab was administered at the doses recommended by the data sheet according to the European Medicines Agency (EMA). Pre-dose and post-dose concentrations of eculizumab were determined, as well as blockade of the classical complement pathway (CH50). Sociodemographic and clinical data were collected, and pharmacokinetic parameters were calculated. To establish the cut-off point for eculizumab concentrations that predicted complement blockade, Receiver Operating Characteristic (ROC) curve analysis was performed. Lastly, the Kruskal-Wallis test was used to contrast the differences in different parameters according to eculizumab concentrations.

RESULTS

Twenty-five patients were included, 19 adults (76.0%) and 6 pediatrics (24.0%), with median ages of 43.4 (IQR 35.7-48.8) and 10.1 (IQR 9.6-11.3) years, respectively. Of these, 22 (88.0%) patients were diagnosed with aHUS and 3 (12.0%) with C3 glomerulopathy. A total of 111 eculizumab concentrations were determined. Mean pre-dose and post-dose concentration values detected during the maintenance phase were 243.8 (SD 240.6) μg/mL and 747.4 (SD 444.3) μg/mL, respectively. Increased complement blockade was observed at higher pre-dose concentrations (p=0.002) and decreased serum creatinine at both higher pre- and post-dose concentrations (p=0.001 and p=0.017, respectively). Using ROC curves, it was determined that a pre-dose concentration >149.0 μg/mL was optimal to achieve complement blockade, with an AUC of 0.87 (0.78-0.95). Finally, high inter-individual (48.9% CV) with low intra-individual variabilities (11.9% CV) in eculizumab clearance were observed.

CONCLUSIONS

The present study reports supratherapeutic concentrations of eculizumab in patients with aHUS, and defines higher concentrations than those described in the data sheet to achieve blockade, thus encouraging the personalization of treatment with eculizumab.

Biological therapy, surgery, and hospitalization rates for inflammatory bowel disease: An observational Latin American comparative study between adults and pediatric patients

OBJECTIVE

Compare the proportions of use of biological therapy, surgeries, and hospitalizations between adults and pediatric inflammatory bowel disease (IBD)-Crohn's disease (CD) and ulcerative colitis (UC)-patients.

PATIENTS AND METHODS

Observational, retrospective, and multicenter study. Data were collected from all consecutive IBD patients seen as outpatients or admitted to hospital, during 2015-2021, in two IBD tertiary centers in a South Brazilian capital. Patients with unclassified colitis diagnosis were excluded from this study. Patients were classified as having CD or UC and sub-categorized as adult or pediatric according to age. Data were analyzed using frequency, proportion, Fisher's exact test, and Chi-square test.

RESULTS

A total of 829 patients were included: 509 with CD (378 adults/131 pediatric) and 320 with UC (225/95). Among patients with CD, no differences were observed for proportions of use of biological therapy (80.2% in pediatric vs. 73.3% in adults; P=0.129), surgery (46.6% vs. 50.8%; P=0.419), or hospitalization (64.9% vs. 56.9%; P=0.122). In UC, significant differences were observed for biological therapy (40.0% vs. 28.0%; P=0.048) and hospitalization (47.4% vs. 24.0%; P<0.001). No significant difference was observed in surgery rates (17.9% vs. 12.4%; P=0.219).

CONCLUSIONS

Biological therapy and incidence of hospitalization were greater among pediatric patients with UC, compared with adults; no difference was observed in the need for abdominal surgery. In CD, no significant difference was observed in the three main outcomes between the age groups.

Galcanezumab: a humanized monoclonal antibody for the prevention of migraine and cluster headache

Migraine is a common, painful and highly disabling neurological condition that has plagued mankind for millennia, but its pathophysiology remained largely obscure until recently. The clinical success of triptans for treating migraine and the discovery that calcitonin gene-related peptide (CGRP) plays a prominent role in migraine led to increased research interest into this disease. An important improvement has been the development of monoclonal antibodies, including galcanezumab, that bind to CGRP or to its receptor, preventing its activation. Subsequent clinical trials have reported that galcanezumab is safe and well tolerated, and is effective in reducing the frequency of migraine attacks in patients with episodic or chronic migraine. At the same time, increased study of the pathophysiology of cluster headache, a relatively rare condition with excruciatingly painful headache attacks (i.e., "suicide headaches"), led to the discovery that, as in migraine, CGRP plays an important role in its pathology. Clinical trials suggest that galcanezumab is safe and effective for the prevention of episodic cluster headache, and it is under study for chronic cluster headache. Galcanezumab is approved for the prevention of migraine in the U.S., the European Union, Canada and Mexico, and was also approved for the treatment of episodic cluster headache in the U.S.

Benralizumab for the treatment of asthma

Benralizumab is a humanized monoclonal antibody directed at the a subunit of the interleukin-5 receptor (IL-5R) that is under clinical development. The binding of benralizumab with the alpha chain of IL-5R results in inhibition of hetero-oligomerization of alpha and beta subunits and thus no signal transduction occurs. Consequently, this inhibition prevents proliferation of eosinophils and basophils and the cascade of events following it. Several pivotal trials have documented that benralizumab reduces asthma exacerbation rates with a significant increase in time to the next exacerbation, statistically improves prebronchodilator forced expiratory volume in 1 second (FEV1) and disease-specific health-related quality of life, and is well tolerated in patients with severe asthma and blood eosinophil counts greater than or equal to 150 cells/mcL.