Phages are not straightforward inanimate and stable substances, but evolvable and natural biological entities. Future sustainable phage therapy concepts should fully acknowledge the potential of the coevolutionary aspect of the phage–bacterium couplet. Only then can the inherent potential of phages as natural biological bacterium controllers be put to use. Indeed, bacteria will inevitably become resistant to phages, but due to the continuously ongoing arms race/competition between the two protagonists, specific phages that are able to infect the formerly resistant bacterial strains can be expected to quickly emerge. However, more experimental evolution studies are necessary to determine the potential negative evolutionary consequences of unlimited phage therapy.
The existing pharmaceutical regulatory framework and business models are not compatible with a dynamic and sustainable phage therapy concept. The actual economic models reduce pharmaceutical companies to 'common button' producers neglecting their main societal role: providing people with adequate products for better health. Therefore, a suitable environment for phage therapy should be developed. Fundamental changes of mentality in the medical and pharmaceutical environment (e.g., towards patentability and restrictive licensing) are essential for a successful introduction of phage therapy in modern (future) medicine. We need to radically reshape our (pharmaceutical) economic models to cater for more sustainable approaches that are beneficial for human survival.
Phage therapy fits well in the new emerging field of Darwinian medicine, where the insights of evolution are fully taken into account. Viruses, among which are phages, were involved in the origin of life itself and play a major role in biological evolution.[78–82] Hopefully, they will play a role in the future control of bacterial disease. We consider our plea for a more realistic approach to phage therapy, which takes into account the coevolutionary aspect of the bacterium and its phage, to be scientifically sound. We must learn from the errors that contributed to the rise of antibiotic resistance. We hope to foster this vision in collaboration with the competent authorities and responsible economic actors, as only a common effort will make it a (direly needed) reality.
Future Virology. 2012;7(4):379-390. © 2012 Future Medicine Ltd.