FDA Approves the Intravenous Immunoglobulin G Yimmugo to Treat Primary Immunodeficiencies

The safety, efficacy, and pharmacokinetics of Yimmugo were evaluated in an open-label, prospective, uncontrolled, multicenter phase 3 trial.

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The FDA has approved immune globulin intravenous, human-dira (Yimmugo; Biotest AG) to treat patients with primary immunodeficiencies (PID). The innovative intravenous immunoglobulin (IVIG) is the first of Biotest’s portfolio to be approved by the FDA.¹

Yimmugo is a newly developed polyvalent immunoglobulin G preparation from human blood plasma that is intended for intravenous (IV) administration. The sugar-free and ready-to-use solution is approved in the US for substitution therapy in primary antibody deficiency syndromes.¹

The safety, efficacy, and pharmacokinetics of Yimmugo were evaluated in an open-label, prospective, uncontrolled, multicenter phase 3 trial (NCT02810444). In this trial, 67 patients 2 to 75 years of age—of which 18 were pediatric patients aged 2 to 17 years—with a diagnosis of PID were enrolled. Patients had a prior established IGIV therapy for at least 3 months with a constant dose, and at least 1 IgG trough level of 5 g/Lor more during the previous 3 months.^2,3

All patients received doses of 100 mg/mL Yimmugo between 0.2 and 0.8 g per body weight (measured in kg) for an approximate 12-month treatment period at intervals of either 3 (n = 12) or 4 weeks (n = 55), with dosage and dosing intervals based on each individual patient’s pre-trial infusion schedule. Patients received a Yimmugo doses randing from 200 mg to 833 mg per body weight, with infusions being initiated at a rate of 0.5 mg/kg/minute for the first 30 minutes, and if these were tolerated, doses were increased to a maximum tolerated rate that did not exceed 13 mg/kg/minute.^2,3

The primary efficacy end point for the trial was the rate of serious bacterial infections (SBIs)—which included bacterial pneumonia, bacteremia/septicemia, osteomyelitis/septic arthritis, visceral abscesses, or bacterial meningitis—over a 12-month period. Additionally, predefined success criteria were demonstrated rate of less than 1 acute SBI per patient per year. Other efficacy end points included the occurrence of any infection, time to resolution of infections, use of antibiotics, the number of days missed from either work or school, and hospitalizations, all of which were assessed after the 12-month treatment period.^2,4

According to the trial findings, the mean IgG trough level was 8.55 (1.67) g/L at baseline and at the follow-up visit following the final Yimmugo infusion, the trough level was 8.84 (2.17) g/L. A total of 260 infusions were administered to the 18 pediatric patients. No SBIs occurred in the pediatric population. Further, there were 5 acute SBIs among the other study participants, all of which were bacterial pneumonia. The investigators also noted that during the trial’s duration, 10 patients required a dose increase because of low IgG levels (n = 7), infections (n = 2), and an adverse reaction, which was a worsening of fatigue (n = 1).^2,3

Additionally, more than 85% of all infusions administered were not associated with any infusion-related adverse event (AE), which start during or within a 72-hour period post-infusion. There were no severe or serious AEs related to treatment with Yimmugo. Additionally, 13 pediatric patients reached a maximum infusion between 2.0 and 8 mL/kg/h, and no AE with an onset during the infusion had occurred at these infusion rates.³

According to Biotest, Yimmugo is 1 of 3 plasma proteins that are on the horizon for US markets. The other 2, according to the company, are both in late-stage development and consist of a fibrinogen concentrate (FC) for the treatment of fibrinogen deficiency, which would be the first FC approved in the US for this indication, and polyvalent Ig trimodulin for the treatment of community-acquired pneumonia or severe community-acquired pneumonia.¹

“The addition of Biotest’s Yimmugo to our strong portfolio of IV and subcutaneous immunoglobulins provides another innovative treatment option for patients with PIDs who rely on these essential medicines in their daily lives,” said Roland Wandeler, President Grifols Biopharma Business Unit, in a news release.¹

References

1. Grifols. Grifols’ Biotest receives FDA approval for innovative Yimmugo® immunoglobulin to treat primary immunodeficiencies. News release. June 17, 2024. Accessed June 17, 2024. https://www.grifols.com/en/view-news/-/news/grifols-biotest-receives-fda-approval-for-innovative-yimmugo-immunoglubulin-to-treat-primary-immunodeficiencies

2. US Food & Drug Administration. Package Insert – YIMMUGO. Accessed June 17, 2024. https://www.fda.gov/media/179364/download

3. Kriván, G, Borte, M, Soler-Palacin, P, et al. BT595, a 10% Human Normal Immunoglobulin, for Replacement Therapy of Primary Immunodeficiency Disease: Results of a Subcohort Analysis in Children. J Clin Immunol. 2023;43(3):557-567. doi:10.1007/s10875-022-01397-0

4. Study to Investigate Efficacy, Safety and Pharmacokinetics of BT595 in Subjects With PID.ClinicalTrials.gov identifier: NCT02810444. Updated July 20, 2023. Accessed June 17, 2024. https://clinicaltrials.gov/study/NCT02810444