Tuesday, July 8, 2014

About that transplant...

Dave’s Great Adventure
Book 5, Chapter 2, Verse 8
July 7, 2014

Dr. Keating came into the exam room and sat down. Then he leaned a bit toward me and smiled the impish smile he often has when we’re talking. “Don’t worry about those terrorists over in the Transplant Clinic,” he said, with his Australian accent.

I had expected to have to make a major decision about a transplant soon, probably at my visit in May. I even had an appointment to see the very kind folks at the Transplant Clinic which had been on my schedule for three months. Each time we get to M. D. Anderson on the morning of my appointments, I always ask for a printout of those appointments to make sure none of the times has changed. But this morning when I got the printout of my appointments and times, the appointment at the Transplant Clinic had disappeared. I was surprised.

So, I got my blood drawn as scheduled and then went to the Leukemia Clinic to await my appointment there. I saw Jackie, as I usually do, and she went over my history and did the usual physical exam. All was well. My labs tests were all stable and my white and red blood cell counts were normal. No evidence of relapsing disease. I told her that I was puzzled about the missing appointment at the Transplant Clinic, as I had expected to be talking about the possibility of a transplant in the fairly near future.

So Jackie completed her exams and questions and left the room, leaving me to await Dr. Keating’s time with me. And that’s when he came in and told me that a transplant wasn’t very likely in my immediate future.

Things are going too well, he said, to think about doing a transplant right now. My marrow seems devoid of disease and my labs and exams are all normal. So, with that subject off the table, I asked some questions I had, questions which had been lingering in my mind, bothering me about what might lie ahead. I had been especially worried about the problem of folks like me with the 17p deletion failing the Imbruvica therapy. I asked, what percentage of us are failing the therapy so far. I had been told only that it was “common” in the past, but had no idea what the magnitude of the failures might be. What was it, I wondered; 80% of us, 50%, what? No, he said, it’s more like 10%, which I found reassuring because, I’m sure (as we all are, of course) that I won’t be in that 10% group. So then I asked, of those who 17p deletion patients who have failed, how many have died. Well, none of them. They are getting treated with various other therapies; some with ABT 199 (another drug in the Imbruvica category), Arzerra (similar to Rituxan but more “humanized”) and other things. Probably some have had transplants, too, but I failed to ask about that. And that I found to be very reassuring. I also asked about how the disease came back when folks relapsed, as I had wondered if it came back as Richter’s or worse. Yes, it does some times, but that apparently is not seen routinely. So, it seems like there is still a lot of good news about this drug and my continued treatment with it.

We moved on to talk about the CARs (chimeric antigen receptors) studies being done at MDA. I have mentioned this new procedure in some of my previous stories, but I’ll touch on it again just briefly…if I can actually be brief! This is the procedure wherein one’s T-lymphocyte white cells are harvested, much like donating blood or platelets and such. But then the patient’s T-lymphs are treated with a modified retrovirus, like an HIV virus, to insert a gene into the DNA of the patient’s lymphs. This gene will do a couple of things. First, and most importantly, the T-lymphs will be modified to search out cells with a specific protein on their cell membranes. All CLL leukemia cells have a protein called CD19 on them and the early studies of CARs have looked at teaching the T-lymphs to kill cells carrying this protein. The second thing that the T-lymphocyte white cells are taught to do is to reproduce when they find and kill such a cell. There have been some notable successes with this approach, including a very few folks who are now, apparently, cured of their disease. But, there is a problem with this approach. Although all CLL white cells carry the CD19 protein, so do all normal B-lymphocyte white cells, and they are the cells that ultimately make your antibodies so you can fight off infections. So, although a few folks have been cured of their disease, they must frequently get infusions of antibodies, gamma globulin infusions, since they can’t make their own antibodies.

The folks at MDA are taking a different approach. One of their colleagues in Sweden discovered a protein on CLL cells called the ROR1 protein. This protein is generally found only on certain malignant cells and a few immature cells. It is not found on normal B lymphocytes. So, if one’s T-lymphs could be modified to search out and kill only cells with the ROR1 antigen, then the problem of the normal B-lymphs getting caught in the crossfire might be solved, along with the problem of not making one’s own antibodies. By the way, ROR1 is also found on kidney, breast, lung and colon cancers, so this could possibly have applications beyond the treatment of CLL.

But there are folks who say they’ve found the ROR1 antigen on other tissues like fat cells, pancreatic cells and such. If that’s correct, and the ROR1 protein is found on these tissues in significant quantities, then it might not be good for the patient. Even if you think it would be okay for your T-lymphs to gobble up your fat cells, the problem could be that they would destroy massive amounts of the cells and the cellular debris could clog up your kidneys, causing “tumor lysis syndrome.” That’s not good at all, and can be deadly. But this problem, if it exits at all, does not seem to be a serious issue in the early going. So, the researchers at MDA have started this process with a very few patients so far. I really don’t know if we’re talking about one or two folks, or if they’ve tried it on six or eight. I just know it’s not many yet. That’s for a couple of reasons.

First, just doing this is very labor intensive, as you can only make one batch of cells for any given patient. My cells, for example, wouldn’t work for anyone else. These things can’t be mass produced in large quantities. So each patient will have his or her own personalized batch of T-lymphs made up for them.

The next reason it’s going slowly, is that it’s a very new process, and as with most very new medical processes, it’s generally tried out first on the folks who are the sickest and have no other options. Therefore, folks like me, who are currently doing well on the Imbruvica, are not really great candidates for a process which has not yet been proven to be effective. So, we’ll see how it goes with the early studies and will hope to see great results without too many complications. If things go well in the study, I may be a candidate somewhere down the road as data is collected on the pioneers of this procedure. Doc Keating says I don’t want to be the first candidate for this new procedure, but that he’ll let me know when they’ve done ten or so with good outcomes!

By the way, all this research on the ROR1 CARs is being done in conjunction with the Transplant Clinic folks, so it’s possible that they are in on the plan to eventually try to get me into the study, and that may be why my appointment with them at my last trip to Houston mysteriously disappeared.

While we’re talking about ROR1, let me also mention that other researchers are working on creating ROR1 antibodies which can be given by injection/infusion to attack CLL cells. This would be very much like the Rituxan I’ve had several times, but would not (like the Rituxan does) affect normal B lymphs cells along with the bad guys. This would have to be given repetitively, like Rituxan, and would not be a cure, as the antibodies would eventually disappear from the patient’s circulation. The advantage of the ROR1 CARs therapy is that it could, in theory, be a cure if the ROR1 treated cells persist indefinitely, continuously seeking out and killing CLL cells wherever they find them. Cool stuff!

So that’s where we are right now. I’ll continue to take the ibrutinib/Imbruvica for the foreseeable future, as long as it keeps working for me and as long as my disease doesn’t find a way around its effects. And we’ll keep an eye on the research being done on the ROR1 CARs procedure, to see if I might ultimately be a candidate.

Until the next time, after my visit to Houston in August.


“Work for a cause,
Not for applause.”