Myeloid growth factors
The history of the myeloid growth factors parallels the development and evolution of biotechnology over the last several decades. The relationship of neutropenia and infection has been recognized since the advent of myelotoxic chemotherapy and was well described in work by Bodey more than 50 years ago (1). However, it was not until the development of in vitro assays for myeloid precursor cells that we could begin to study myeloid development. These cell culture systems also facilitated the subsequent studies of the myeloid growth factors that were designated at G-CSF (granulocyte colony-stimulating factor) and GM-CSF (granulocyte macrophage colony-stimulating factor) based on their differential stimulatory effects of myeloid colonies in vitro (2). In the 1980s, these colonystimulating factors were subsequently purified, cloned, and placed into early human clinical trials within a matter of a few years. Likewise, from the onset of the first human trials in the mid to late 1980s to the approval of G-CSF and GM-CSF in 1991 by the FDA was equally rapid. This accelerated timeline can be attributed to a number of factors, including the decades of prior scientific discovery leading to the biotechnology revolution, the pressing need for these agents in the clinic, their relative safety and efficacy, as well as a more streamlined process for drug development compared to our current standards.
