Tuesday, February 20, 2018

New Stanford Immunotherapy

A few of you have left comments or sent emails about this news story, and I'm finally getting around to writing about it. (I've been unusually busy these days. It's a good problem to have -- it means I'm healthy enough to be busy.)

The news comes out of Stanford University. The press release from Stanford is called "Cancer 'Vaccine' Eliminates Tumors in Mice."

This is one of those pieces of news that gets reported in a lot of places and gets people very excited. But those kinds of stories (for those of us who have been through this before) usually mean we need to slow down and read carefully and not get too excited.

The study being reported deals with an Immunotherapy method that seems simpler and less expensive than some others. (I'm thinking about CAR-T, for example.) In this method, two very very small amounts of two agents are injected directly into tumors. (In the study, which used mice, there were tumors in many different locations in the body, not just lymphomas.)

And these are really small amounts -- measured in micrograms (a microgram is one millionth of a gram). That's so small I can't even think of a way of comparing it.

The two agents that are injected are, first, a CpG oligonucleotide, which is a short piece of DNA. This works with cells nearby to hep activate a receptor on T cells called OX40. It's basically sending a  signal to cells that they need to get ready to attack. The second thing is an antibody that latches on to the OX40 on those T cells. When that happens, the T cells (part of the body's immune system that attack invaders) now know which cells to attack -- that antibody has told them what to look for.

The T cells do their thing and find and attack cancer cells. But even better -- T cells don't stay in one place in the body. They move around and look for more of those same cells to attack. So if there are tumors is in more than one place, the activated T cells will find them and attack them, too.

The T cells are targeted -- they will only look for the cancer cells they are told to look for. So when the researchers used a mouse with both Lymphoma and colon cancer, but only set t up for the T cells to look for the Lymphoma cells, the colon cancer cells were ignored.

The results were impressive. 87 of 90 mice had their cancer cells wiped out. The other 3 were given a second round, and that did the trick.

the results were good enough to have a phase I clinical trial start last month. While the mouse study involved lots of types of cancer, this trial will look at 15 Lymphoma patients.

There are lots of reasons to be hopeful about this. Immunotherapy is big these days, and this treatments seems to work in a way that makes sense -- finding ways to stimulate the immune system to do its job on cancer cells, which normally find ways to fool the immune system. It also has Dr. Ronald Levy as its senior researcher (he's a genuine Lymphoma Rock Star -- he played a big part in developing Rituxan).

But the usual cautions apply here. It was tested on mice, not humans. Obviously, there are going to be some differences.

But that's why we have clinical trials. A phase I study will see if it really works the way we think it will (and hope it will). It will give us a sense of safety -- what kinds of side effects that might come from this treatment, short term and longer-term.

We know that lots of promising treatments sound great when they are given to mice, but never make it to phase 2 or 3, let along to approval.

The good news is, even if it doesn't work, we'll learn something from that and try again.

(I know, I'm an optimist.)

Definitely something to keep an eye on.

(And again thanks to everyone who sent me the link.)


1 comment:

Savepig Invest said...

A commentator I follow touched on this recently:

"If our goal was to cure cancer in mice we would be almost done now"