The future of cancer treatment is targeting: killing only the cells you want to kill, with no side effects or harm. Discrimination and control is the benefit brought by advances in biotechnology, and the results presently tested in the laboratory are a world removed from even the best contemporary chemotherapy or radiation treatment.
A number of different technology platforms are under development within the paradigm of targeted cell killers:
- First is the nanoparticle: comparatively simple structures whose behavior researchers can expect to fully understand. They only do what they are designed to do, which is typically to act as an inert link between a homing device and a kill mechanism.
- Second is the engineered virus, altered natural self-replicators that are restricted to working their characteristic havoc only upon the target cell type.
- Thirdly, we have engineered immune cells. The immune system already tries to attack and destroy cancers, but some are invisible to it. If immune cells can be given the right biochemical tools to recognize the enemy, then they will fight and win.
You might think of these strategies as falling on a scale of complexity: at the level of nanoparticles, researchers are working with systems simple enough for outcomes and side-effects to be confidently predicted or quickly established in the laboratory. Viruses are more capable and more complex, and the immune system yet more capable and complex. The trade off here lies in speeding development by use of an existing complex biological system that has already evolved to perform the task you have in mind versus the greater difficulty of predicting how that system is going to behave in the field as a therapy.
Via Singularity Hub, I see that trials are fairly advanced for the first generation of engineered immune cell based therapies for cancer; pull out cells from the patient, alter them to better kill cancer cells, then return them to the body.
It's been almost a year since we covered Dendreon announcing its successful Phase III clinical trials for its prostate treatment Provenge. Now, the Seattle based company is continuing its work of getting Provenge, also known as Sipuleucel-T, to the market. The revolutionary treatment for metastasized prostate cancer uses the body's own immune system to hunt down and kill cancer cells that have spread beyond the organ. Upgrading the immune system's T-cells with special proteins, a process called Active Cellular Immunotherapy (ACI), lets them hunt down cancer cells via the antigens embedded on their surface. ACI seems to work well for prostate cancer and Dendreon is expanding it to treat bladder, breast, ovarian and colon cancer with Lapuleucel-T (which has already completed Phase I trials).
Though I’m certainly impressed with Sipuleucel-T/Provenge and excited by Lapuleucel, I think the real story here is ACI. It may take us years before nanoparticles can actively effect the growth of cancer. Immune system cells, however, are a form of quasi-nanotechnology that we can tap into in the near term.
That multiple competing strategies exist and are fairly advanced is a good sign for the future of this field: in the past few years, I have seen significant advances in cancer therapies based on targeting via nanoparticle, virus, and immune cell. All more reasons as to why I'm not too concerned about the cancers that wait in my personal future.