At the recent Annual Meeting of the American Society of Clinical Oncology (ASCO; 1–5 June 2018, IL, USA) meeting, data was presented highlighting the survival rates for patients who completed the KEYNOTE-006 Phase III study, for pembrolizumab given to unresectable or metastatic melanoma patients. It also gave insight on the follow up of patients who had a response. Of those who did the entire 2-year cycle of treatments, 86% remained without progressive disease 20 months after stopping.
In other words, 89 of 109 patients that had either a complete response, partial response, or stable disease didn’t get any worse for nearly 2 years after coming off the anti-PD-1 drug. As someone who has made the decision to stop my treatment of the same drug, this was encouraging, to say the least. Now there is legitimate science to show what many oncologists had already hinted at – a couple years of immunotherapy for SOME patients will be enough medicine to get a durable response.
We are starting to see, long-term, what happens when a person’s immune system is fired up to eradicate cancer cells. We can now add evidence to the thought that “many of the responders to checkpoint inhibitors hold that response for a significant amount of time.” Two years may not seem like much to the average person, but when given a late-stage melanoma diagnosis, 2 years was longer than the average remaining lifespan on chemotherapy. For many who respond to the anti-PD-1 drugs, it has become both the length of time for medication and the current benchmark for post-treatment, cancer-free survival. Those lucky ones are not just playing with house money; they are coming out way ahead with little sign of relapsing.
Choosing when to come off a treatment or trial is an extremely difficult decision process – compounded by the lack of long-term data for newer drugs and combination treatments. I was afforded the ability to speak with a number of melanoma specialists to gain a consensus “best guess” before halting my anti-PD-1 treatments last summer. But many oncologists will not have access to much more than ASCO abstracts and conversations with colleagues to base their decision; patients have even less hard evidence of what choice is “right”.
It’s not as simple as hitting a milestone to figure out when to cease. There are other factors to consider when deciding on a treatment’s next steps – the physical toll the medicine may be taking on your body (both short- and long-term) while remaining ON treatment; and the mental and emotional toll of choosing to come OFF treatment.
The former can be mitigated, somewhat, with good care, but at some point there is a concern of giving a person TOO much of a good thing without really knowing what it is doing to the rest of your immune system. (With 75 doses in trial, I can at least say I did my part trying to further science!) Immediate adverse effects of checkpoint inhibitors are well-documented, but the longer-term side effects are still being understood. As one well-versed immuno-oncologist once told me: “while we don’t think it’s a serious risk, we really don’t know what these drugs do to a person’s immune system over time.”
However, the mental impact is just as important a consideration. Patients getting a good response will have to address cutting off the medication at some point. Choosing to come off a drug that may have just saved you life can be unnerving, especially if you are NOT in the No Evidence of Disease category. “Will going off of this cause my disease to return/grow?” is a question any cancer patient should weigh before choosing to stop medication; it’s the biggest fear most of us will have.
There is no perfect answer, at least not currently in the melanoma and immunotherapy world. I felt like I had gathered enough information to make an informed decision with my oncologist, and we discussed my treatment plan over several visits before choosing to stop the anti-PD-1. Every patient, and every situation, is unique, though, and what might be “right” for one person might not be the answer for another. When asked if I should continue my treatment, nearly every oncologist began their response with a form of, “Well, the data shows that…”, a somewhat frustrating exercise in balancing probabilities with human insight.
Statistics give us the best possible measuring stick for comparing pharmaceutical treatments to one another, but they cannot weigh the myriad of factors that go into deciding what an individual should do at a given point in time in their medical journey. They are simply one more informative tool used by someone, with guidance from a medical professional, to choose their path. The ASCO results are fantastic to hear; they give credence to the potential of a durable response, and although oncologists tend to shy away from using the word, they even offer the hope of a “cure” to metastatic cancer.
As patients get better responses with new therapies, the question of “when to stop treatment” will be one posed to clinical oncologists with more and more frequency. Having evidence to support a decision is a great result of a follow up study. Being able to work through that choice with a patient is the best outcome of all.
Biography: T.J. Sharpe is a Stage IV melanoma patient who shares his journey through cancer in the Patient #1 Blog on www.oncology-central.com, www.philly.com/patient1/, www.SkinCancer.net, and on www.NovartisOncology.com. He was diagnosed in August 2012 with melanoma tumors in multiple organs, only 4 weeks after his second child was born. Since then, he has undergone six surgeries and four immunotherapy treatments over two different clinical trials. The initial failures, and subsequent complete response, have been chronicled in his blog posts since December 2012. In addition to writing, he is a keynote speaker and consultant to the biopharma and clinical research industries, bringing an educated patient voice as a true stakeholder in challenging healthcare’s status and making a difference in patients’ lives via his company, Starfish Harbor LLC. A South Jersey native, T.J. lives in Fort Lauderdale, FL, with his wife Jennifer and two young children, Josie and Tommy.