The Food and Drug Administration (FDA) has approved Panzyga® (immune globulin intravenous [human] – ifas 10% liquid preparation; Pfizer) for the treatment of adults with chronic inflammatory demyelinating polyneuropathy (CIDP) to improve neuromuscular disability and impairment.

The approval was based on data from a prospective, double-blind, multicenter study (  NCT02638207) that compared 2 different maintenance dosages of Panzyga in 142 adults (ages 18 to 83 years) with CIDP. Patients were randomly assigned 1:2:1 to receive first a loading dose of 2g/kg, and then 0.5g/kg, 1g/kg or 2g/kg according to their respective dose arm for 7 maintenance infusions at 3-week intervals during the 24-week dose-evaluation phase; those in the 0.5g/kg and 1g/kg arms had the option of rescue treatment with 2 consecutive infusions of 2g/kg at 3-week intervals if criteria were met.

The primary efficacy outcome was based on the proportion of responders, defined as a patient with a decrease of at least 1 point in the adjusted 10-point Inflammatory Neuropathy Cause and Treatment (INCAT) disability score.

Results showed that almost 80% (55/69) of patients in the 1g/kg arm responded to treatment. Findings also showed a dose-dependent response based on the proportion of responders in the 2g/kg dose arm in the adjusted INCAT disability score (91.7%; 33/36), and the proportion of responders in the 1g/kg and 2g/kg dose arms in the grip strength (65.2% and 83.3%, respectively), inflammatory Rasch-built Overall Disability Scale (55.1% and 72.2%, respectively) and Medical Research Council sum score (72.5% and 86.1%, respectively).

Based on these findings, the FDA approved 2 maintenance dosing options for CIDP; the treatment can also be administered at infusion rates up to 12mg/kg/min. “Each patient with CIDP has different treatment needs, and we have found that having one approved dosing option is not always optimal,” said Angela Lukin, Global President, Hospital Business Unit, Pfizer Inc. “The approval of this new indication with additional dosing options helps address an unmet patient need by providing health care providers with the ability to choose an approved dose that’s right for patients.”

The most common treatment-emergent adverse reactions reported in the study included headache, fever, dermatitis, and increased blood pressure. The Panzyga labeling also carries a Boxed Warning regarding the risk of thrombosis, renal dysfunction, and acute renal failure.

In addition to the CIDP approval, Panzyga is also indicated for the treatment of primary humoral immunodeficiency in patients 2 years of age and older, and in adult patients with chronic immune thrombocytopenia to raise platelet counts to control or prevent bleeding.

Panzyga is supplied as a solution containing 10% IgG (100mg/mL) in 1g, 2.5g, 5g, 10g, 20g, and 30g single-use bottles.


  1. US FDA approves Panzyga® for the treatment of adults with chronic inflammatory demyelinating polyneuropathy (CIDP). [press release]. New York, NY; Pfizer; February 12, 2021.
  2. Panzyga®. [package insert]. New York, NY: Pfizer; 2021.