Anti-CD47: A Way to Cure Cancer

One drug called anti-CD47 has the capabilities to cure not one type of cancer, but all forms of cancer. Breast, colon, lung, prostate, and liver can all be cured with an antibody drug that is created from a protein already found inside the body.

CD47 is a protein that protects healthy parts from the immune system when it goes into attack mode. The problem is that tumors use this protein to protect themselves from the immune system. This was first discovered by biologist Irving Weismann around a decade ago at Stanford University School of Medicine. He discovered that leukemia cells had higher traces of CD47 than other healthy parts of the body.

Weismann discovered that by using an antibody to block the CD47 the immune system was able to recognize lymphomas and leukemias as a threat to the body in mice. What is really impressive is that most recently Weismann and colleagues have discovered that CD47 is not only present on these types of tumors but all tumors, and they always seem to have higher levels of the protein than healthy cells.

They ran tests by placing the cancerous cells in a petri dish with an immune cell called macrophages and anti-CD47. They discovered that when the cancer cell was placed only with the macrophages, the cell was completely left alone; however, when they added the anti-CD47 the macrophages attacked the cell.

They also ran tests by implanting tumors in the feet of mice because they are easier to spot in this area. Out of the ten mice injected with human bladder cancer, 10 out of 10 mice had cancer spread to the lymph nodes. After treatment with anti-CD47, only one of the mice showed any cancer in the lymph nodes, and this tumor was showing signs of shrinkage. The mice with colon cancer injected had shrunk to less than one-third of its original size. All five mice that were injected with breast cancer cells had complete elimination of all cells after being treated with anti-CD47.

Although Weismann was positive about the results, “We showed that even after the tumor has taken hold, the antibody can either cure the tumor or slow its growth and prevent metastasis.” Other researchers such as cancer researcher Tyler Jacks of the Massachusetts Institute of Technology in Cambridge feel this study still has a long way to go. He said, “The microenvironment of a real tumor is quite a bit more complicated than the microenvironment of a transplanted tumor.”

There is also some questioning about anti-CD47 also attacking blood cells when it is released. Although the mice do increase their production of new blood cells, this might be something to stay alerted to. Also, the effects of combining anti-CD47 with chemotherapy could be counterproductive if the body is producing more CD47 as a result of the stress the treatment puts on the body.

The study has been given a $20 million grant from the California Institute for Regenerative Medicine for human testing. Weismann is fully confident about the results he expects to see and said, “We have enough data already that I can say I’m confident that this will move to phase I human trials.”