HyQ phase III study data in patients with primary immunodeficiencies presented at ACAAI meeting

Baxter International Inc. (NYSE: BAX) today announced the presentation of its phase III study data for HyQ, an investigational combination immunoglobulin (IG) product for use in patients with primary immunodeficiencies (PI). The study evaluated efficacy and safety as well as the pharmacokinetics, infusion volumes, intervals, and rates compared to patients' previous intravenous immunoglobulin (IGIV) administration. Results from the study were presented on Saturday, Nov. 5, during the American College of Allergy, Asthma and Immunology annual meeting in Boston.

“In addition to a reduced rate of serious bacterial infections, the phase III study data suggest potentially useful attributes of HyQ, such as the possibility for a three or four week dosing schedule with single-site, self-administered infusions, which patients may appreciate”

"In addition to a reduced rate of serious bacterial infections, the phase III study data suggest potentially useful attributes of HyQ, such as the possibility for a three or four week dosing schedule with single-site, self-administered infusions, which patients may appreciate," said Mark Stein, MD, Medical Director of Allergy Associates of the Palm Beaches, and investigator in the phase III trial.

The phase III prospective, open-label study enrolled 89 patients with PI in the United States and Canada, and evaluated the effectiveness of HyQ in the prevention of infections and measured other secondary endpoints including tolerability. Study participants received recombinant human hyaluronidase (rHuPH20) administered subcutaneously followed by IG 10 percent infused subcutaneously through the same needle at a dose of 108 percent of the patient's previously prescribed IG dose (administered intravenously).

The majority of patients infused their HyQ dose in a single site and nearly 98 percent of infusions were completed without changes in infusion rate due to tolerability. The most common local adverse reactions were discomfort/pain, erythema, swelling/edema and pruritus. Systemic adverse events occurred in 8.3 percent of HyQ infusions compared to 25 percent of IGIV infusions in the control arm.

In HyQ treated patients, serious validated bacterial infections (SBIs) occurred at an annualized rate of 0.025, which is lower than the threshold set by the FDA of less than 1.0 annually, and the annual rate of all infections was 2.97. Further, HyQ was bioequivalent to IGIV at 108 percent of the IV dose at 3- or 4-week intervals. HyQ provided a lower peak IG concentration compared to IGIV, similar to weekly IGSC, with trough levels similar to every three or four-week IGIV treatment. Baxter has submitted applications for marketing approval of HyQ in the United States and in Europe, both of which have been accepted for review by the regulatory authorities.

"These data support the potential clinical benefits of HyQ that, if approved, will make it an attractive therapeutic option for physicians and their patients with primary immunodeficiencies," said Professor Hartmut Ehrlich, vice president, R&D, Baxter's BioScience business.