If I wanted to go into treatments that are already FDA approved for metastatic SCCHN (squamous cell carcinoma of the head and neck), I don’t have many options. There are no FDA approved immunotherapy treatments for SCCHN yet. There are only a few chemo agents approved. Alternatively, it could be submitted to insurance as treatment for NSCLC (non-small-cell lung cancer, my second diagnosis) which opens up two options: Opdivo and Keytruda.
Opdivo and Keytruda are both anti-PD1 antibody drugs. They attempt to disrupt one of the communication pathways cancer cells can use to “fool” immune system T-cells into ignoring them rather than destroying them. Both drugs operate on the principle that your immune system will destroy the cancer (or at least keep it in check) if you can stop the cancer cells from using this communication path.
Not everyone’s cancer uses PD-1 for communication, so the success rates are low for both Opdivo (20%) and Keytruda (23%). There’s no evidence yet that the drugs operate differently, or whether patients for whom Opdivo didn’t work might find success with Keytruda, or vice versa.
So in FDA-approved land, Opdivo or Keytruda are my only choices for immunotherapy.
When I go into the Land of Clinical Trials, more options unfold but many of them are similar: either a new phase 1 drug or a combination trial. I ended up choosing between two.
- At UCLA, my oncologist offered a clinical trial for Pfizer’s new anti-PD1 antibody. It’s a phase 1 trial so there’s no data on its effectiveness, but since it’s very similar to Opdivo and Keytruda, it probably has a similar profile in terms of success rates and side effects.
- At The Angeles Clinic, where I got my second opinion, they offer a combination trial that pairs Opdivo with Epacadostat, an IDO1 inhibitor. The Epacadostat attempts to stop the cancer from slowing down immune cell production in general. Together, the theory is that the two drugs create a 1-2 punch where the Epacadostat helps the immune system generate more cells while the Opdivo enables those cells to more effectively spot and target the cancer. This is also a phase 1 trial, but early results and the results from a previous trial that paired Epacadostat with Keytruda show a success rate as high as 35% (as opposed to the usual 20-23% rate of Opdivo or Keytruda alone).
“Success” in these trials is measured in what’s called “progression-free survival” or the amount of time the patient’s cancer was either stable or shrinking while on the treatment. Unlike with targeted treatments, where a patient must have the genetic mutation for the treatment to be effective, no one can predict whether an individual patient will respond to a specific type of immunotherapy. You try it for a period of time, they monitor the cancer, and if after 3-4 sessions there is continued growth, you check that one off the list and try something else. Even for patients that respond to Opdivo or Keytruda, the response time varies from 3 months to much longer–some patients are still on it after the original trials 4-5 years ago.
So when presented with the choice of a clinical trial with a new anti-PD1 antibody at UCLA (one of the top cancer treatment centers in the country, and the place where I was already being treated) and the combination trial at The Angeles Clinic (affiliated with Cedar Sinai, specializing in immunotherapy), I based my choice on where it feels like my roll of the dice has the best odds.
The benefit to the UCLA trial is that, if it failed, I would still be able to move on to Opdivo and Keytruda–effectively having three drugs to try. But there’s no evidence right now that failure on one anti-PD1 antibody means you could still respond to a different anti-PD1 antibody… so that’s an unproven benefit. Meanwhile the trial of Epacadostat with Keytruda has a proven benefit of the specific second agent in combination with an anti-PD1 antibody so there’s every reason to believe it will show the same results with a similar anti-PD-1 antibody in my trial (which uses Opdivo instead of Keytruda).
The downside to both trials that they’re phase 1 dose escalation and safety trials. The addition of a second immune affecting agent has, in previous trials, amplified the side effects (which are otherwise usually lighter for immunotherapy versus chemotherapy). It also amplifies some of the potentially serious/deadly side effects, such as pneumonitis and severe allergic reactions. Since the point of a phase 1 trial is to determine safe doses, it may push some boundaries. On the other hand, I’m younger and healthier than the average cancer patient.
After discussing the choices with Charlie and doing some research, I decided to enter the combination trial at The Angeles Clinic. I’ve been accepted and, pending the screening and some tests, I should start in around two weeks (since I have to taper off the prednisone first).
There’s also a third trial that’s both very promising and very interesting. I’ll write about it next.