Cancer Vaccine

It seems like there's a hot "cancer story" in the news every few months. The most recent one is about lymphoma. 

The news stories are about an article in Nature Medicine called "Systemic Clinical Tumor Regressions and Potentiation of PD1 Blockade with In Situ Vaccination." Like many of the exciting new treatments from the past few years, this one is an immunotherapy.

In general, immunotherapies try to use the body's immune system to kill cancer cells. The immune system is usually very good at finding invaders (like bacteria and viruses) and killing them off. One of the big problems with cancer is that it's not really an invader -- it's the body's own cells that have gone rogue. Cancer cells also play some neat tricks, turning switches on and off that keep the cells from dying. All of those things make it really hard for the body's natural defense -- its immune system -- to do its job on those cells.

When immunotherapy works, it's an amazing thing. Take CAR-T, for example. The body's T Cells, part of the immune system, are removed and then changed so they recognize the cancer cells. What's really amazing is that it keeps on working. Chemotherapy gets processed by the body and then you need more. But T Cells multiply, and travel around the body, so when they find an invader that they recognize, they attack (and then signal the body to create more T cells to look for the invader). It's beautiful.

With this new immunotherapy, that same process is at work. Researchers created an "in situ" vaccination. That means they found the original place where the cancer started, and put some immune system stimulants right at that place. The three stimulants are "Flt3L, radiotherapy, and a TLR3 agonist." Together, they signaled dendritic cells, a kind of immune cell, to tell some T Cells to find particular cancer cells. Then the T Cells traveled through the body and looked for more of those cancer cells and destroyed them.

The study being described was a small trial involving 11 patients with indolent lymphoma (9 of them had Follicular Lymphoma). Of the 11, two had a Complete Response (they were both FL grade 1/2, stage 3a -- my exact diagnosis). Six had a partial response, and three had stable disease. Common side effects were fever and flu-like symptoms.

Because the immune cells travel to other parts of the body, the results have led to new studies involving solid cancers. That makes sense -- the treatments can be placed into the original tumors and then the immune cells can potentially take care of tumors that have popped up in other parts of the body.

The headlines are very exciting. Most say it is "promising,"though I aw one that said it could be a "game-changer." People in online groups are using those headlines to start getting a little too excited about this.

I like the word "promising" in all of those headlines. That's accurate. It's a very small study that resulted in 2 people getting Complete Responses. I'm not sure I'd go with "game-changer" just yet. Maybe after a phase III study with a couple of hundred people and more CRs, but not just yet.

It's a good reminder to balance hope and realism. As Follicular Lymphoma patients, we have a lot to be hopeful about. There are some very exciting things happening in research these days. And we're fortunate to have a bunch of pretty good treatments available to us right now, which could keep us in good shape until those really exciting treatments are shown to be as good as some of the hype.

(This is a good time to reminder everyone, too, that none of those exciting treatments can come to us without people to participate in clinical trials. So please consider the possibility if the time comes.)

Stay hopeful.