Friday, July 24, 2009

Pomalidomide Is Still Working

Mayo Clinic Visit Thursday, July 23, 2009, end of Cycle 18:

I started on the Mayo Clinic phase-II trial of pomalidomide, then called CC-4047, almost a year and a half ago. My M-spike, a measurement of proteins from the malignant cells, dropped from 2.7 down to 1.1 g/dL within four 28-day "cycles." Since then it has slid a little more, mostly hovering between 1.0 and 0.9. Today it was 0.8 g/dL. Whoopee! Down is always good. It has been down to 0.8 once before. Dr L put a little smiley face on the results printout, next to M-spike.

So is this a real downward change in the M-spike or just a variation in the test itself? M-spike is a notoriously variable test. Well, Immunoglobulin G (IgG) is exactly the same as it was 28 days ago, 1010 mg/dL. Since IgG and M-spike tend to track each other, perhaps the decrease in M-spike is false. On the other hand, Lambda light chains dropped 26% to 1.95 mg/dL, by far the lowest I've seen in six years of living with myeloma. This is another erratic test, but it appears to be valid because Kappa light chains are unchanged. Most of the Lambda light chains come from the malignant cells, so perhaps the decrease in M-spike is real.

Whatever. One can analyze these things way too much. Better to celebrate a little, because for sure M-spike didn't go UP, and then wait 28 days for the next result.

Peripheral neuropathy (PN) is still an issue. Mine is still mild, with some partially-dead spots and some tingling in the bottoms of my feet and one thumb. Happily, it seems to be stable, not getting worse any more. I'm putting together another post on neuropathy and hope to publish it soon.

Related links:

      My Myeloma     A discussion of my myeloma, not very technical.
My Treatment History Not technical.
My Test Charts Graphic displays of several key test results over time.
My Test Result Table Best with a wide browser window. Very "technical."

Side effects of the two key drugs, CC-4047 and dexamethasone, are discussed in a previous post. Add peripheral neuropathy to the list.

Here are a few of the latest test results:

Test Apr 30   May 28   Jun 25   Jul 23   Remarks
M-spike g/dL 0.8 0.9 0.9 0.8 Best tumor measure
IgG mg/dL 1060 1030 1010 1010 Variation is normal
L FLC mg/dL 2.55 2.60 2.63 1.95 L Free light chains
Calcium mg/dL 9.6 10.0 9.6 9.7 Below 10.2 is best
Creat mg/dL 0.9 1.0 1.0 1.1 Kidney, lower is better
HGB g/dL 14.3 14.4 14.0 14.8 Hemoglobin, normal
RBC M/uL 4.01 4.06 3.93 4.13 Red cell count, low
WBC K/uL 3.6 4.0 5.6 3.9 White cells, normal


Sunshine and I also discussed with Dr L:
  • I told her that because of the muscle wasting and other side effects I wanted to reduce the DEX dosage, currently 8 mg, but because the trial doesn't allow the DEX to be increased again I would refrain from proposing that. Her response led me to believe that the DEX, now at only 8 mg once per week, may not be doing that much good anyway, and we should revisit the issue in another month. I'm up for that.
  • I mentioned that I had gained a few pounds since the beginning of the trial, but that because of the muscle wasting from DEX my body had changed shape, with a layer of fat on my belly and chest. I told her that I had gone back on Weight Watchers to get the weight under control, and re-started a resistance training program to try to reverse the muscle wasting. She approved.
  • I mentioned that I had recently done a difficult run with a heart rate monitor, which reported an average rate of 126 and a maximum of 142 beats/min. These numbers are perhaps ten beats/min lower than they should be. I mentioned that I had looked back at similar records while I was on thalidomide, in 2004 and 2007, and seen similar reductions in exercise heart rates. She acknowledged this and said that it happens with Revlimid as well.
  • She asked if I felt tired, noting that I had apparently said I was tired in a checkup last December. I said no, I wasn't any more tired than a 68-year-old should be, and certainly not chronically tired. I can just see the doctor's writeup: "patient denies feeling tired." :-)
  • We discussed peripheral neuropathy. I've accommodated to it somewhat, as it seems to have reached a stable level, with some tingling and partial loss of feeling in my feet, not getting any worse. I mentioned that I am taking the full regimen of supplements and also keeping my feet warm, as I believe that warmth aids healing. She said that she also believes that stimulation helps, and suggested massage as well.
  • For 17 cycles I took the pomalidomide at bedtime and, on DEX days, took the DEX with dinner. For this past cycle I took the pomalidomide before breakfast and the DEX with breakfast. I mentioned that I preferred taking the DEX in the evening, and she didn't think it would make much difference. Indeed, the change to morning meds didn't seem to make much difference in this past cycle, though it certainly didn't hurt either.
  • She said a few things about pomalidomide that I won't report because they are not yet published, but I think these are OK and I hope I got them right:
    • 82% of trial patients got at least a 25% reduction in M-spike.
    • About the same percentage of patients have responded to pomalidomide as respond to Revlimid, but many of these have previously failed Revlimid.
    • Patients with high-risk genetics are experiencing encouraging responses.
    • One patient in particular did not respond for six months, and then the M-spike dropped very dramatically.
    • Other patients have reached a plateau, level for several cycles, followed by a gradual drop to still-lower numbers.
    • Her theory as I understood it: Pomalidomide first reduces the tumor burden directly by interfering with NF-kB and possibly by other mechanisms as well. Then the body's own immune system is able to continue the good work and improve on it.
    • She said that malignant cells pop up within each of our bodies all of the time, but our immune systems normally spot those and kill them.
    • Some patients reach a plateau, as I have, and then just stay there, as patients sometimes do on Revlimid. I hope that's me - she hopes so too.
  • I showed Dr L a chart of blood glucose versus time of day (below), with DEX taken at breakfast. She remarked that it didn't seem too bad, meaning that the glucose never went too high, even at meals. I mentioned that we do try to minimize carbohydrates on DEX day, and she said that was a good idea.
Other Stuff:

As part of the study I get an electrocardiogram (ECG) every three cycles. This time the cardiologist reported "marked sinus bradycardia with sinus arrhythmia." Bradycardia is simply a low heart rate - mine was 38 this time, the lowest ever. No surprise, though, I'm a runner with an endurance athlete's heart, and with the added effect of the pomalidomide I always get a comment about bradycardia. I don't recall getting a comment about "sinus arrhythmia" before, but as far as I can tell that just means that the interval between beats is not perfectly regular. Dr L didn't bother to comment on it.

For the upcoming cycle I plan to take the pomalidomide in the morning, usually before breakfast, and the DEX Sunday evening with dinner.

Also, one of the people who post on the MMA List recently noted that alcohol is a neurotoxin, and said that his neuropathy improved when he stopped having his evening glass of wine. It's worth a try, so I may also find an appropriate window of days and stop enjoying my one evening beer for at least a week, just to see if there is any improvement. Sigh.

Blood Glucose v. Time.  Click to enlarge
Chart of blood glucose versus time, after 8 mg DEX taken with breakfast. You can see the spikes caused by lunch and dinner. Glucose was normal by the next morning, so that effect of the DEX seems to clear within about 24 hours.