Storage advance for adenoviruses
store adenoviruses so that they remain viable for over a year.
The technology overcomes one of the hurdles facing the use of these viruses in genetics therapy products. Adenoviruses have been widely used to carry genes into human cells, although their ability to stimulate an immune reaction has limited their therapeutic use to areas such as cancer.
Introgen's patent (No 6,689,600) covers the technology for producing long-term storage-stable adenovirus that, according to the company, "may eventually replace formulations currently in use by the adenovirus industry by providing conveniences and efficiencies in storage, distribution, pharmacy handling and clinical administration".
Adenoviral particles intended for human therapeutic applications must maintain their structural integrity to remain biologically active, and the viral structure can easily be compromised during the formulation process.
Extended periods of storage of adenoviral vectors in traditional formulations can exhibit diminished biological activity. For this reason, current adenoviral therapeutics are typically formulated in buffers containing glycerol, which permits their storage for extended periods. However, such formulations must be maintained and transported at extremely low temperatures.
Scientists from Introgen's adenoviral formulations group have discovered that the inclusion of one of a series of bulking agents together with one or more protectants permit adenoviral therapeutics to be maintained for over a year in regular refrigerated conditions (4 degrees) with very little loss of biological activity, and several years longer if stored under regular freezer conditions (-20 degrees).
David Parker, Introgen's vice president of intellectual property, said that the discovery was particularly surprising, given that the method makes use of conventional pharmaceutical additives yet represents a "very broad enabling technology … to promote the long-term storage stability of viral preparations".
Introgen's investigational drug, Advexin, was granted a fast track priority review by the US Food and Drug Administration last year as a treatment for head and neck cancer last year. The product is currently in Phase III trials.
