Friday, August 17, 2012

Vaccine Update

Biovest, the company that makes the (as yet unapproved) BiovaxID vaccine for Follicular NHL, announced on Wednesday that they are essentially getting a second shot at approval for the vaccine. In a deal with the FDA, Biovest is going to design and conduct a second phase III trial for the vaccine. If Biovest follws the FDA guidelines for the trial (which it intends to do), and the trial confirms the results from the first phase III trial, then BiovaxID will likely be approved.

I've always been excited about the idea of a vaccine. A few days after I was diagnosed, I saw a lymphoma specialist at Yale, who told me that there were many options for treating Follicular Lymphoma, and more in the pipeline. And he seemed especially excited about the idea of a vaccine. Such vaccines have been developed for other cancers, but NHL vaccines have been less successful. So far, anyway.

Cancer vaccines are not like vaccines for, say, measles. They aren't intended to prevent a disease. Rather, they are meant to train the body's immune system to recognize and attack cancer cells that already exist.

BiovaxID works by targeting cancerous B cells. (Something like Rituxan targets healthy B cells, too, since both cancerous and healthy cells have the CD20 protein).  BiovaxID is individualized for each patient -- it is made with each patient's cancer cells, so it is guaranteed to target those cells, rather than assuming all follicular lymphoma cancers are the same. The vaccine is developed so that the immune system is trained to recognize the unique idiotype (a protein on the surface of the cell -- this is what the "ID" in the name stands for) on the cancer cells. When the immune system encounters cells with this idiotype, it destroys them, the way it would destroy a flu cell, for example, or some other invader.

 Trial results have been pretty positive; patients who have received the vaccine after chemotherapy went disease-free for about 44 months (median). Those in the control arm went 30 months. Careful study of the results, though, showed something interesting: patienst who received the vaccine who had a specific kind of ideotype (IgM) did much better than those with a different type (IgG). This difference is going to be taken into consideration as they design the new phase III trial. We'll have to wait a few more months to see what happens, and how exactly they factor in the IgM idiotype.

So, overall, this is good news. The bottom line is, this is a vaccine that will likely work as a consolidation therapy -- kind of like Rituxan Maintenance, given to prolong the remission from chemo. But the differences between, say, Rituxan (or even Zevalin) are significant enough to give another option should those treatments not work after chemo.

More hope.

No comments: