Visible and subvisible particles in the BCG immunotherapeutic product Immucyst®.

Bacille Calmette-Guerin, BCG, is a live attenuated bovine tubercle bacillus used for the treatment of non-muscle invasive bladder cancer. In this study, an Electrical Sensing Zone (ESZ) method was developed to measure the particle count and the size of BCG immunotherapeutic (BCG IT), or ImmuCyst® product using a Coulter Counter Multisizer 4® instrument. The focus of this study was to establish a baseline for reconstituted lyophilized BCG IT product using visible and sub-visible particle concentration and size distribution as reportable values.