Gammagard Liquid Approved for Chronic Inflammatory Demyelinating Polyneuropathy

The Food and Drug Administration (FDA) has approved Gammagard Liquid^® (immune globulin infusion 10% [human]) to improve neuromuscular disability and impairment in adult patients with chronic inflammatory demyelinating polyneuropathy (CIDP).

The approval was based on data from the prospective, open-label, single-arm, multicenter phase 3 ADVANCE-CIDP 2 study (ClinicalTrials.gov Identifier: NCT02549170), which evaluated the efficacy and safety of Gammagard Liquid in adults with CIDP who developed a relapse in the ADVANCE-CIDP 1 study after receiving treatment with HyQvia^® (immune globulin infusion 10% [human] with recombinant human hyaluronidase).

Study participants received Gammagard Liquid at an induction dose of 2g/kg body weight, followed by maintenance infusions every 3 weeks for a period of 6 months; dose adjustments were made according to the investigator’s discretion. Efficacy was based on responder rate, defined as an improvement of functional disability indicated by at least a 1 point decrease in the adjusted Inflammatory Neuropathy Cause and Treatment (INCAT) disability score at the completion of the IV treatment period (6 months) or the last study visit of the IV treatment period, relative to pre-IV treatment baseline.

Results showed a responder rate of 94.4% (95% CI, 74.2-99.0) at 6 months with 17 out of the 18 participants having an adjusted INCAT score returning back to baseline values prior to study enrollment. All participants had improvement in functional ability, which was measured as a composite of INCAT score, grip strength, and Rasch-built Overall Disability Scale score.

The most common adverse reactions reported were headache, pyrexia, anemia, leukopenia, neutropenia, illness, increased blood creatinine, dizziness, migraine, somnolence, tremor, nasal dryness, abdominal pain upper, vomiting, chills, nasopharyngitis, and pain in extremity.

Gammagard Liquid has not been studied in immunoglobulin-naive patients with CIDP. Maintenance treatment with Gammagard Liquid in CIDP has not been evaluated for periods longer than 6 months. According to the prescribing information, not all patients require indefinite maintenance therapy in order to remain free from CIDP symptoms. Any treatment beyond 6 months should be individualized based on the patient’s response and demonstrated need for continued therapy.

Gammagard Liquid is also indicated as a maintenance therapy to improve muscle strength and disability in multifocal motor neuropathy. It is also indicated as a replacement therapy for primary humoral immunodeficiency.