Hizentra Cuts Infections in Immune Disorders
ORLANDO -- Subcutaneous immune globulin (Hizentra) remains safe and effective up to two years in the treatment of patients with primary immunodeficiency diseases, researchers reported here.
The overall rate of infections was 2.4 per patient-year (95% CI 1.9 to 2.9) among patients receiving once-weekly infusions of the subcutaneous immune globulin, according to Robert P. Nelson, Jr., MD, of Indiana University in Indianapolis, and colleagues.
And the rate of serious bacterial infections was 0.06 per patient-year, which consisted of two cases of bacterial pneumonia, the researchers reported in a poster session at the annual meeting of the American Academy of Allergy, Asthma, and Immunology.
Conventional therapy for conditions such as common variable immunodeficiency or X-linked agammaglobulinema has been monthly infusions of intravenous immune globulin.
The treatment is needed lifelong to prevent patients from recurrent bacterial infections and chronic pulmonary disease.
In a previous shorter-term study (52 weeks), the subcutaneous route of delivery was associated with fewer systemic adverse events than the intravenous formulation.
"The weekly subcutaneous treatment leads to stable serum IgG levels, and smooths out the peaks and troughs," Nelson told MedPage Today during a poster session.
To assess longer-term outcomes, he and his colleagues followed 21 patients from four U.S. centers from 11 to 104 weeks. Most patients were white women, and their mean age was 42.
Patients who had lymphoid malignancies, hypoalbuminemia, and proteinuria were excluded from the study.
Maximum infusion rates were 35 mL/h (one pump) or 70 mL/h (two pumps) with the maximum volume being 40 mL/site (≤4 sites/infusion). Premedication was not given.
]Most infusion were given at home and self-administered. The median duration of treatment was 87 weeks.
Five patients withdrew but only one because of an adverse event, which was thyroid cancer unrelated to treatment.
Adverse event and local reaction rates were similar among subjects infused at low (<35 mL/h), medium (35-50 mL/h), and high (>50-70 mL/h) rates.
The most common infections were sinusitis, nasopharyngitis, bronchitis, and upper respiratory tract infections.
The annual rate of school or work days lost because of infection was 4.3 per patient-year, while the rate of hospitalized days was 0.55 per patient-year.
The rate of days on antibiotics for prophylaxis or treatment was 84 per patient-year.
Mean serum IgG levels remained steadily in the range of 11.71 g/L and 12.76 g/L throughout the follow-up period.
Treatment-related adverse events occurring within 72 hours of the infusion included headache, at an incidence of 0.004 events per patient-year, and fatigue, at a rate of 0.005 per patient-year.
Headache tends to occur more frequently with intravenous administration, the investigator said.
No patients experienced oropharyngeal pain or had an increase in creatinine.
Infusion reactions were similar regardless of whether patients had low, medium, or high infusion rates.
The rate of any temporally associated, treatment-related adverse events was 0.013 per patient year, which was "substantially lower" than in a previous study (0.034), despite higher mean infusion rates being used in this longer follow-up trial, Nelson reported.
Patient satisfaction was high, with overall scores on measures of health being close to those reported by healthy individuals, and there was no clinically significant deterioration in health-related quality of life.
