Newsletter - How Long Can This (Maintenance Therapy) Keep Going On?

(Adapted from Ace)

A Message from Dr. Tony Blau

If there were an Olympic Games for the number of decisions that a cancer patient must make over the entirety of their disease course, we myeloma patients would be gold medalists. Great drugs keep us alive for years - often many. Yet this pesky disease almost never completely surrenders. While remissions for many other types of cancer can hold some hope of a cure, we myeloma patients can count on our disease to one day return. Myeloma is reliable that way. And when myeloma returns, it typically isn’t as responsive to treatment as it was at diagnosis. That’s the reason that I have adopted a strategy of squishing my myeloma and keeping squished, as described in a video that can be found by clicking here. This strategy involves achieving and maintaining measurable residual disease (MRD) negativity, a state in which no myeloma cells are detectable, a topic that is described in this video.   

But while no myeloma cells are detectable in my bone marrow or PET-CT, I believe that they are likely in there, hunkered down and biding their time until they can grow back to cause problems someday. The following paragraph attempts to explain why.  

The most sensitive test for detecting myeloma in the bone marrow is clonoSEQ, described in this video. ClonoSEQ testing is done on bone marrow samples and can detect as few as one myeloma cell per million bone marrow cells. Wow, that’s impressive. But what I really want to know as a myeloma patient is how many myeloma cells remain in my body? Of course, the answer to that question is unknowable, but here’s what I think. ClonoSEQ testing indicates that I have fewer than one myeloma cell per million bone marrow cells. But there’s a rub: the human bone marrow is estimated to contain about 700 billion bone marrow cells (according to a paper co-authored by my dear friend and eminent scientist Chuck Murry). If one does the math, that means that I can be MRD negative as assessed by the most sensitive test available but still harbor up to 700,000 myeloma cells in my body. So while my wife Sibel would like to think that my MRD negative status means that I have zero myeloma cells, cold math suggests that I might still harbor upwards of 700,000 myeloma cells. It’s for this reason I have been taking maintenance therapy for a long time.  

I take two drugs: Revlimid, which I have taken daily for more than five years, and Ninlaro, which I’ve taken for almost four years. In pursuing this strategy, I’ve been super lucky. First, I tolerate the drugs well, with the exception of gastrointestinal side effects that prompt the occasional need to rush to the bathroom at unpredictable (and sometimes inconvenient) times (by the way, this side effect seems very responsive to the consistent use of bile acid binders such as colestipol and colesevelam). Second, I have excellent insurance, so I can get these drugs despite their insane expense. My insurance company pays about $427,000 per year, while I pay less than $1,000 per year. But nothing in medicine is free. Every drug has a side effect, and for patients with myeloma, there are all sorts of side effects that might accompany long-term maintenance therapy. One of the biggies is secondary malignancies, i.e., cancers caused in part by the very medicines that I am using to keep my myeloma at bay.  

So should I stay on these ultra-expensive medicines in an effort to keep my myeloma on the mat while accepting the risk that these very medicines might contribute to the development of another cancer that might be awful? Or should I let up the pressure on my myeloma and see what happens? In making this assessment, I came up with the following idea. Let me get a recently developed, extremely sensitive blood test designed to detect mutations associated with a variety of different types of cancers. The test and test results are shown here:

Negative - so there you go. Of course, this test isn’t definitive, but it appears that, at the moment, I don’t have an obvious reason to change course. I will likely continue to choose the path of “long-term maintenance therapy guinea pig.” It’s kind of pathetic, really. The dearth of information available to us patients makes it impossible to know the right choice.  We can only do our best and learn from each other.