Tobacco derived cancer vaccines for non-Hodgkin's lymphoma: perspectives and progress.

Everyone appreciates the irony of using tobacco plants to cure cancer. (1) Recently featured in a populist Wall Street Journal article, (2) the use of plants to produce medicinal products was presented as novel, even though we are decades into development of numerous products for specific medical applications (reviewed extensively in (3, 4)). Though the tobacco plant and its relatives offer a qualified set of advantages for producing complex biologicals, and in many cases overcome problems that plague traditional expression systems, FDA licensed products derived from bioengineered plants have yet to appear in the marketplace. Despite a difficult beginning, recent advances in plant biotechnology have been as cutting edge as those in the fields of molecular biology and chemical engineering, which now position the field for a new level of commercial relevance. The basis for this review is a description of the first FDA qualified parenterally administered vaccine clinical trial using a plant derived product. We have confirmed in this trial that plant proteins can be qualified to the same level as biologicals from other sources, and are safe when given as injected vaccines. Most importantly though, immune responses to plant proteins were seen in 66% of cancer patients, and these responses were to the desired antigenic determinants, not to xenogenic plant antigens. Problems and solutions that arose during the development of a safe and effective human vaccine are discussed.