IVIG Reduces Grade 2 Infections by 67 Percent in CLL

A study conducted at the University of California, San Diego has found that intravenous immune globulin (IVIG) reduces grade 2 infections by 67 percent in patients with chronic lymphocytic leukemia (CLL). 

The researchers reviewed outcomes for 52 patients with a median age of 68 years and a mean interval of 9.3 years from CLL diagnosis; the median (IQR) age at diagnosis was 58 years (52-64) with CLL. Patients were initiated IVIG between 2005 and 2022, with their median overall start occuring in 2014, and infection rates were compared in the 12 months before and after treatment started. Findings showed all patients had experienced at least 1 Common Terminology Criteria for Adverse Events infection of grade 2 or higher (infection requiring oral antimicrobials or outpatient management) in the year prior to IVIG initiation, with a mean of 2.1 infections per patient.

Following the start of IVIG, which was dosed at 0.4 g/kg every 28 days per National Comprehensive Cancer Network guidelines, only 17 patients (33 percent) experienced a grade 2 or higher infection, and the mean per-patient count dropped to 0.4. The relative risk  reduction was 67 percent, with an absolute risk reduction of 67 percent and a number needed to treat of 1.5. According to the authors, this final result is evidence of meaningful clinical impact at the individual patient level. Grade 3 infections requiring hospitalization or intravenous antimicrobials fell from four patients (eight percent) in the pre-IVIG year to two patients (four percent) in the follow-up year, although the authors caution that these events were too infrequent to support strong conclusions.

 In addition,mean baseline immunoglobulin G (IgG) was 389 mg/dL (range 93-891), and 75 percent of patients fell below the 500-mg/dL threshold commonly used to guide IVIG replacement therapy initiation; the remaining 13 were started on IVIG based on clinical concern for immune dysfunction and recurrent infections despite marginally higher IgG levels. Seventy-seven percent had received prior or concurrent CLL-directed therapy.