Much of the future of medicine will involve altering the mix of protein machinery and signals that drive our metabolism, instructing cells to take specific actions, and delivering new protein machines that can perform tasks that our existing biology cannot, such as clearing out otherwise resistant metabolic waste products. The current model in medicine is for the work of mixing up the necessary new materials to take place outside the body, which are then delivered in the form of infusions, injections, pills, and so on. In the future, we will probably see the creation of therapeutics move inside the body, in the form of increasingly sophisticated, reactive, and programmable implanted medical factories.
The work noted here is an early step in this direction: a single-function implant that alters the behavior of immune cells on an ongoing basis, an alternative to periodically drawing cells from a patient, altering them in culture, and then returning them to the body.
A cross-disciplinary team of scientists, engineers, and clinicians announced today that they have begun a Phase I clinical trial of an implantable vaccine to treat melanoma, the most lethal form of skin cancer. Most therapeutic cancer vaccines available today require doctors to first remove the patient's immune cells from the body, then reprogram them and reintroduce them back into the body. The new approach, which was first reported to eliminate tumors in mice [in 2009], instead uses a small disk-like sponge about the size of a fingernail that is made from FDA-approved polymers. The sponge is implanted under the skin, and is designed to recruit and reprogram a patient's own immune cells "on site," instructing them to travel through the body, home in on cancer cells, then kill them.
The technology was initially designed to target cancerous melanoma in skin, but might have application to other cancers. In the preclinical [study], 50 percent of mice treated with two doses of the vaccine - mice that would have otherwise died from melanoma within about 25 days - showed complete tumor regression.