Tuesday, July 1, 2014

A New Vaccine for Follicular Lymphoma?

The blog for Mount Sinai Hospital put out a kind of teaser called "Novel Vaccine Fights Lymphoma" a few days ago. It's a little short on the kind of detail that would let me look into it all a little more, but it gives just enough to make me want to read more.

Researchers at the Tisch Cancer Institute at Mt. Sinai have developed a kind of internal vaccine. It works differently from the way something like BioVaxId works. With BioVax, a patient's immune cells are taken from the blood and trained to recognize cancer cells, then put back into nthe blood to go to work.

This one from Mt. Sinai is different. The focus here is on Dendritic Cells. Dendritic cells are important players in the immune system. In general, when someone's body is invaded by bacteria or a virus or something else that isn't supposed to be there, immune system cells go after it and kill it off. Dendritic cells are the middle men -- they first encounter the invader and then tell the immune cells what's going on, and let them know what kind of invader cell they should be looking for. They're like Bubbles from the The Wire, hanging around on the corner and then telling the police what he saw. (Sorry -- I just binge-watched all 5 seasons of The Wire on Amazon Prime.)

The point is, Dendritic Cells have to do their job of identifying an invader, and telling the immune system cells, before the immune system can attack an invader.

Now, the Mt. Sinai research is trying to take advantage of this natural system. Two "immune-modifying medicines" are injected into the tumor (presumably an effected lymph node; I'd really like to know what the medicines are exactly -- this is one of those places I'm getting sucked in by the tease). The patient is also given two days of low-dose radiation directly into the tumor. (This is standard radiation, not RIT.)

The first medicine sends the Dendritic Cells to the tumor, where they recognize the cells that have been affected by the radiation. The second medicine sends the Dendritic Cells out to the immune cells in the rest of the body, where they learn to recognize the cancer cells and track them down in the rest of the body.

What this is doing is giving the immune system a little push. Under normal circumstances, the immune system would recognize an invader, and all the various cells would do their jobs. But cancer isn't a normal circumstance, and the immune system is deceived by cancer cells. It needs a little help in recognizing and catching the bad guys. (Like Bubbles putting the red hats on the Barksdale crew. Gosh, I hope I'm not the only one out there who watches The Wire....)

This is very early research. Two patients in a trial experiences Partial Responses. But it's encouraging enough to warrant a larger trial of 30 patients.

The lead researcher, Dr. Joshua Brody, plans to present all of this at Lymphoma Conferences starting this summer. It will be interesting to see how the community reacts to it, and how it all gets refined as the research moves along.

Definitely worth keeping an eye on....


Karl Schwartz said...

Thank you for the balanced description of the trial (what's known and not yet known). It seems a sound concept overall. Systemic responses can occur with radiotherapy alone ( abscopal effects) .. so unless the rate of responses are sufficiently high (?) a controlled study might be needed to determine that the immune adjuvants contributing. Late risks of therapeutic doses of radiation (even if low) could be an issue especially for younger patients?

Lymphomaniac said...

I'm a little puzzled in general about the role of radiation in this treatment. Good point about the radiation beings systemic, too. Still lots of questions. Like I said, I saw this as a teaser, and I'm curious to read more of the details when they come out.

Karl Schwartz said...

Bob, My understanding of it is that the low dose radiotherapy induces killing of the lymphoma cells which then release tumor-specific antigens ... which are "processed" by the immune cells - which can lead to a vaccine effect. The second phase of the protocol is to inject an immune adjuvant into the previously irradiated lymph node to enhance that effect.