Tuesday, October 8, 2013

Immunotherapy

ASCOPost, an online publication from the American Society of Clinical Oncology, featured an interview a few weeks ago with Dr. David Porter, who is doing some interesting work in Immunotherapy, specifically with Leukemia patients. He talks about some of the advances in Immunotherapy that have come about in the last few years, and speculates about advances in the fairly near future.

Immunotherapy, basically, is the use of the body's own immune system to fight off cancer. Probably the best known Immunotherapy for Follicular Lymphoma patients is Rituxan, which works in several ways, all of which work with the immune system to kill off the cells. Cool video alert! 

As Dr. Porter makes clear, immunotherapy works because the treatment finds a target that is unique to the cell. (Rituxan finds CD20, which is present on B cells, the white blood cells that get all cancery.)

The challenge over the next 10 years, says Dr. Porter, will be in finding the targets on those cells.

I think that's less of a problem for Follicular Lymphoma. We've had some pretty great success with CD20. In addition to Rituxan, it is also the target for Zevalin and Bexxar, the RadioImmunoTherapies (I refuse to let Bexxar die, even if the current owner is going to stop manufacturing it), and the monoclonal antibody Ofatumumab. We also know that Follicular Lymphoma cells express CD10, CD19, and CD22. That's a bunch of targets, and already a bunch of treatments available and in the pipeline to go after them.

My guess is, given that we're ahead of a lot of other cancers when it comes to immunotherapy targets, our goals for the next few years will be 1) developing more and better immunotherapy agents. So far, nothing seems to beat out Rituxan enough to make us want to switch over. And with cheaper generic versions of Rituxan on the horizon, we're going to need something big; and 2) we're going to need to find some combinations of immunotherapies or other agents that show improvement over what we have (R + R, Rituxan + Revlimid, comes to mind).

(By the way, don't you love how I say "We," as in "We need to develop better treatments," like I'm in a lab coat looking through a microscope? I think it comes from it being baseball playoff season, as in, "We can't allow the Rays to win in the ninth like that again." Put me in, coach.)

Speaking of combinations, the other interesting comment that Dr. Porter made had to do with chemotherapy. It's not going anywhere, he says. I think he's right.

I've made snarky comments about clinical trials with CVP and Fludarabine, and how out-of-fashion they are, but my point isn't that they shouldn't be used anymore. It's that trials should be focusing precious resources on newer, more promising, focused treatments. (Which is actually the case -- I don't know of any brand new trials for older chemos, other than CHOP and its variants, or Bendamustine.)

Chemo is here to stay for a while, because it works, especially with refractory patients. Finding a good immunotherrap-chemo combo is the trick (R-CHOP and R-B certainly are proving effective). So is using immunotherapy agents to deliver targeted doses of chemo, rather than relying on the scattershot approach that traditional chemo takes.

So, while the interview wasn't focused on Follicular Lymphoma, it still provides some food for thought.

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