Pfizer gets US FDA approval for PANZYGA to treat chronic inflammatory demyelinating polyneuropathy

Pfizer announced that the US FDA has approved the supplemental Biologics License Application (sBLA) for PANZYGA (Immune Globulin Intravenous [Human] – ifas 10% Liquid Preparation) to treat adult patients with a rare neurological disease of the peripheral nerves called chronic inflammatory demyelinating polyneuropathy (CIDP). PANZYGA is the only intravenous immunoglobulin (IVIg) with two FDA-approved maintenance dosing options for CIDP. PANZYGA can also be administered at infusion rates up to 12 mg/kg/min.

CIDP is a rare disorder of the peripheral nerves characterised by gradually increasing symmetrical motor and sensory loss and weakness associated with loss of deep tendon reflexes. It is caused by damage to the covering of the nerves, called myelin. The gradual onset of CIDP can delay diagnosis by several months or even years, resulting in significant nerve damage that may limit and delay the response to therapy. Most individuals will require long term treatment; nearly a third of CIDP patients will progress to wheelchair dependence if left untreated. Early recognition and proper treatment are critical in helping patients avoid a significant amount of disability.

The approval for this new indication was based on data from a prospective, double-blind, randomised, multi-centre Phase 3 study in 142 patients diagnosed with CIDP. This Phase 3 study was the first and only IVIg CIDP treatment study to evaluate more than one maintenance dosing option. Efficacy, safety, and tolerability was observed during seven maintenance infusions at three-week intervals over a six-month period. The primary efficacy endpoint was the proportion of responders in the 1.0 g/kg PANZYGA treatment arm at six months relative to baseline. A responder was defined as a patient with a decrease of at least one point in the adjusted 10-point Inflammatory Neuropathy Cause and Treatment (INCAT) disability score.

The primary endpoint was met with 80 per cent of patients in the study achieving an INCAT response with the 1.0 g/kg dose. Dose-dependent efficacy was shown by several supporting endpoints, including a 92 per cent response in adjusted INCAT score in the 2.0 g/kg dose arm. Dose-dependent responses were also demonstrated in the 1.0 g/kg and 2.0 g/kg dose arms in grip strength, Inflammatory Rasch-built Overall Disability Scale (I-RODS) and Medical Research Council (MRC) sum scores. PANZYGA was generally well tolerated. The most common adverse reactions (>5 %) across all dosing arms were headache (15%), fever (14%), dermatitis (10%), and blood pressure increase (8%). During the study 11 patients (8%) received premedication.

PANZYGA was approved by the US FDA in 2018 for the treatment of primary immunodeficiency (PI) in patients two years of age and older and chronic immune thrombocytopenia (cITP) in adults.

Pfizer and Octapharma AG are parties to a license agreement pursuant to which Pfizer is granted rights to market and commercialise PANZYGA in the US Octapharma retains exclusive rights to commercialise this product globally outside of the US.