Might a Major Development in CLL Treatment Be in Sight?

I was perusing the Web looking for interesting CLL news, when I decided to look at Dr. Kipps’ Blood Cancer Research Fund site (www.bcrf.org). The site now posts news from “Blood”, the periodical of the American Society of Hematology (www.hematology.org).

I noted an interesting editorial from Dr. Byrd on the discovery by researchers of the National Institutes of Health of a single antigen on CLL cells that may be common to all CLL cells. (An antigen is a protein that is the target of an antibody.) Dr. Byrd practically gushes with enthusiasm for the possibilities for CLL and other blood cancers from this discovery (http://bloodjournal.hematologylibrary.org/cgi/content/full/114/20/4324). In fact, his editorial is entitled, “Hunting for the Achilles’ Heel of CLL”. He terms the value of the process in identifying the antigen common to CLL cells as ‘immense’.

That sound like extremely good news!

What the researchers did was to look at people who were cured of their CLL by allogenic stem cell transplants (SCT). They then compared the blood to the patient’s blood and CLL cells that were preserved from the time before they had their transplants. (Research such as this is the reason donating blood for research is so important.)

Using sophisticated techniques, they were able to identify an antibody to an antigen that was present on the CLL cells in these patients before their transplants. The antibody wasn’t present in the patients (otherwise they presumably would have never developed CLL in the first place), but was produced from the donor’s stem cell derived B lymphocytes. It appears that, once the donor’s stem cells start producing those lymphocytes in the transplant patient, somatic hypermutation (which is the process where by all antibodies are produced by the body), starts working to produce an antibody which then starts to destroy CLL cells.

Byrd envisions development of this work to leading to therapies that may improve the curative potential of stem cell transplants. He also suggests that this may find a place in non-transplant therapies in treating CLL and other blood cancers. Avoiding the very expensive, very complex, very disruptive, and dangerous STC would be highly desirable!