Cell-based therapeutics: the next pillar of medicine

Abstract

Two decades ago, the pharmaceutical industry-long dominated by small-molecule drugs-was revolutionized by the the advent of biologics. Today, biomedicine sits on the cusp of a new revolution: the use of microbial and human cells as versatile therapeutic engines. Here, we discuss the promise of this "third pillar" of therapeutics in the context of current scientific, regulatory, economic, and perceptual challenges. History suggests that the advent of cellular medicines will require the development of a foundational cellular engineering science that provides a systematic framework for safely and predictably altering and regulating cellular behaviors.

Fig. 1. Killer apps

Although small molecules and biologics will always have important therapeutic niches, there are numerous applications for which cells are better equipped. Four killer applications for cell-based therapeutics are shown: immune cells engineered to recognize and kill tumor cells, transplanted microbiota that detect and treat intestinal inflammation (e.g., Crohn’s disease) by producing an anti-inflammatory small molecule or biologic, a combination bacterial/mammalian cell therapeutic in which the bacterial cell converts dietary sugars into a nonabsorbed fermentation product and activates the production of a satiety-inducing hormone by the companion human cell therapeutic, and patient-specific stem cells for regenerative medicine [not discussed herein, but see (13)]. iPSCs, induced pluripotent stem cells.

Fig. 2. Evolution and (beyond) tinkering

The sustainable growth of a cell-based-therapeutic industry requires the evolution of a foundational science of cellular engineering. Fundamental knowledge and capabilities developed by cellular engineering scientists will allow us to move beyond tinkering toward systematic mechanisms for predictable modulation of cell proliferation, migration, communication, and the production of small molecules and biologics.