Institute for Stem Cell Biology and Regenerative Medicine

(8/15/14) Update on the anti-CD47 cancer therapy clinical trials

The phase-1 clinical trial of the anti-CD47 antibody is designed to test its safety. The trial will accrue one patient per month at very low doses, and the first groups of participants have been identified from among current Stanford Cancer patients. Currently we are not recruiting new patients to this trial.

If enrollments do open up in the future, that information will be posted on this page. When and if enrollments open up, potential inclusion in this phase-1 trial will be based solely on physician referrals. If there are openings for new participants, and if you meet certain requirements, information posted on this page will describe how your physician can submit a request to the clinical trials team to consider your participation.  

Given the limited nature of this safety trial, we urge that patients not delay or forgo recommended treatments in hopes of participating in this research effort.



CD47 is a kind of protein that is found on the surface of many cells in the body. It tells circulating immune cells called macrophages not to eat these cells. The body uses the CD47 protein to protect cells that should be protected and to help dispose of cells that are aged or diseased. For instance, red blood cells start off with a lot of CD47 on their cell surface when young but slowly lose CD47 as they age. At some point, the amount of CD47 on the surface of an aging red blood cells is not enough to stave off the macrophages, and those older cells are devoured and destroyed, making way for new red blood cells. In this way, the supply of fresh blood cells is constantly replenished.

Unfortunately, some cells that should be destroyed are not. Researchers at Stanford have discovered that nearly every kind of cancer cell has a large amount of CD47 on the cell surface. This protein signal protects the cancer against attack by the body's immune system. Stanford investigators have discovered if that they block the CD47 "don't-eat-me" signal through the use of anti-CD47 antibodies, macrophages will consume and destroy cancer cells. Deadly human cancers have been diminished or eliminated in animal models through the use of anti-CD47 antibody.

Clinical Trials in humans

After the successful outcomes of the experiments testing the use of anti-CD47 antibodies against human cancers transplanted into mice, plans were immediately begun to start clinical trials in humans. Unfortunately, the process of preparing for human clinical trials is long. The initial experiments were done in animals and the animal versions of anti-CD47 antibody cannot be used in humans. So researchers first have to create a "humanized" antibody to CD47, then the production of antibody must be scaled up in a sterile facility of the kind that is used to create other pharmaceutical products. Finally, clinical trials must be designed so that the data they generate will produce a valid scientific result, and the trials must be approved by regulatory officials.

All of this takes time.

For the last year, many people have been working to make clinical trials possible. We are now hopeful that the first human clinical trials of anti-CD47 antibody will take place at Stanford in mid-2014, if all goes well. Clinical trials may also be done in the United Kingdom.

As we get closer to clinical trials, we will start posting information about enrollments on this page.

Other Stanford clinical trials can be found through this page.

The National Institutes of Health Clinical Trials Database can be searched here.


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