Privigen (immune globulin intravenous [human], 10% liquid, CSL Behring) has received FDA approval for an additional indication: the treatment of adults with chronic inflammatory demyelinating polyneuropathy (CIDP) to improve neuromuscular disability. CIDP is a rare autoimmune disorder that affects the peripheral nerves and may cause permanent nerve damage. The biologic was initially approved to treat primary immunodeficiency (PI) and chronic immune thrombocytopenic purpura (ITP) in 2007.
The FDA approval for CIDP was based on results from two phase 3 clinical studies that focused on the use of immunoglobulin therapy for treating the disease: the Polyneuropathy And Treatment with Hizentra (PATH) study, the largest controlled clinical study in CIDP patients to date, and the Privigen Impact on Mobility and Autonomy (PRIMA) study. In PATH, 207 patients receiving Privigen were studied for up to 13 weeks, and 73% responded to Privigen over the course of treatment, as measured by their adjusted score on the Inflammatory Neuropathy Cause and Treatment (INCAT) scale, which measures the ability to walk and perform tasks. In PRIMA (n = 28), 61% of patients responded to Privigen over 25 weeks, as measured by their adjusted INCAT score.
“It is a priority in the care of CIDP patients to provide therapies that improve and maintain strength and function while at the same preventing relapses and minimizing side effects. However, current treatments do not work for all CIDP patients,” said Mazen M. Dimachkie, MD, Professor and Director of Neuromuscular Division, Executive Vice Chairman of the Department of Neurology at the University of Kansas Medical Center and an investigator in the PATH study, in a press release. “Privigen’s approval by the FDA for the treatment of CIDP means that people with CIDP and their treating physicians have gained another treatment option that is safe and effective in helping improve strength and motor function, while potentially delaying disease relapse.”
“People living with CIDP can experience a progression of their disease, which may result in tingling, muscle weakness, fatigue and other symptoms that limit their daily activities and decrease their quality of life,” said Lisa Butler, executive director of the GBS-CIDP Foundation International. “The approval of this intravenous immunoglobulin to improve disability represents an important treatment advance for the patients, caregivers, and families who are struggling with CIDP.”
Privigen is the first and only 10%, ready-to-use, room-temperature stored, liquid intravenous immunoglobulin stabilized with proline. A naturally occurring amino acid, proline has been shown to reduce immunoglobulin G aggregation and dimer formation. Privigen has been approved to treat CIDP in Europe since 2013.
In clinical studies of patients being treated for CIDP, the most common reactions, observed in more than 5% of patients, were headache, asthenia, hypertension, nausea, pain in extremity, hemolysis, influenza-like illness, leukopenia, and rash. Serious adverse reactions were hemolysis, exacerbation of CIDP, acute rash, increased diastolic blood pressure, hypersensitivity, pulmonary embolism, respiratory failure, and migraine.
The prescribing information for Privigen includes a boxed warning for thrombosis, renal dysfunction, and acute renal failure.