ABSTRACT
This chapter outlines several characteristics distinguishing the development process for biologic agents. The rational and efficient development of a new biologic agent for the treatment of such autoimmune diseases as rheumatoid arthritis is difficult. In general, the biologic agents in autoimmune disease therapy have immunomodulatory functions. The goal is to utilize them as therapeutic agents to achieve either a sustained or maximal augmentation of a relevant immune effector function. A very important aspect of studying biologic agents is the use of biologic markers to measure the effect of their administration. In studying biologic agents, if an accurate biologic marker is available, it is possible to look at single administration of the product and after an appropriate washout period, move to repetitive administration, even in the same patient at the same dose level. Alternatively, biologic agents may be the exception to the long rheumatologic tradition of partially effective disease modifying antirheumatic drugs.
