First Generation: Murine
Therapeutic antibodies for treatment of human disease were first developed from mice (murine) about twenty-years ago. Although still available as drugs, murine antibodies have limited therapeutic value, because when injected they are recognized by the human body as foreign substances. The ensuing human immune response neutralizes the foreign antibody, thus limiting its effectiveness and even resulting in dangerous side effects, such as anaphylaxis.
Second Generation: Chimeric
Soon after the arrival of murine antibodies for treating human disease, therapeutic antibodies were introduced that were fusion molecules, combining murine and human antibody segments. These so called chimeric antibodies have achieved great commercial success, and include the blockbuster product Rituxan®, used to treat certain kinds of cancer.
Third Generation: Humanized
While chimeric antibodies were finding their way into human therapies, other sophisticated approaches to further reduce murine content of antibodies were well underway. In addition to the fusion of murine and human segments that comprised the chimeric antibodies, humanized antibodies further interspersed human sequences into the murine segments. From 2003-2006, sales growth for therapeutic antibodies was primarily driven by the humanized products, although chimeric antibodies continued to hold strong market positions.
Fourth Generation: "Fully Human"
More recently, research and development efforts in the industry have centered on the production of so called "fully human" antibodies. Despite the reassuring title, these antibodies have actually not been selected in a human but are engineered, or produced in mice that have been genetically modified with human antibody gene sequences. Extensive clinical experience with these antibodies now indicates that fully human antibodies are indeed immunogenic.
Next Generation: True Human™
True Human™ antibodies are derived from a naturally occurring human antibody that has undergone development and selection inside a human. The True Human™ antibody gene is cloned directly from a human gene, using proprietary methods and technology to ensure faithful reproduction of the original human gene.
True Human™ antibodies faithfully cloned from a human will naturally not be detected by the human immune system as a foreign substance. True Human™ antibodies will be "invisible" to the body's immune system and thus exhibit better safety, efficacy and commercial value compared to earlier generation antibody therapeutics. Accordingly, the Company believes that its True Human™ antibodies represent the first of a next generation of antibody therapy.
Shortcomings of past technology (i.e. "Fully Human" antibodies):