Thursday, June 26, 2008

Equivocal Results

In early March I joined a phase-2 trial (study) of Celgene's new IMiD drug CC-4047, with once-weekly dexamethasone. The first three cycles brought very good results, each with approximately a 25% reduction in markers, but this fourth cycle was less spectacular. My two primary markers are IgG and M-spike:
  • IgG is actually up 15%, definitely the wrong direction and suggesting an increase in monoclonal protein. However, IgG has a normal variation because it responds to bacterial and viral threats to the body, so the increase may be entirely normal and could mask an actual decrease in monoclonal protein.
  • M-spike is down 8%, and although that test is the best measure of monoclonal protein, it may only be accurate to 5% or 10%. Lambda free light chains are also down slightly, however, which does lend more credence to an actual decrease in M-spike.
I get to interpret these results as I please, and I say that there is a modest decrease in monoclonal protein and therefore, most likely, a decrease in tumor burden. So there.

Side effects of the two drugs, CC-4047 and dexamethasone (DEX), are described in a previous post.

We will continue with 2 mg of CC-4047 daily and 20 mg DEX once weekly for the fifth cycle. Here are some related links:

    My Myeloma     A discussion of my myeloma.
My Treatment History Not technical.
My Test Charts Charts of key results over time.
My Test Result Table Needs a wide browser window. Technical.

Other things that Sunshine and I discussed with Dr. L today:
  • I have noticed a slightly irregular heartbeat, an occasional extra beat actually, on two mornings while laying in bed on my left side, both times a day or two after taking the DEX. The irregularity goes away if I move off my left side. Neither Dr. L nor I are very concerned about it.
  • I am NO fan of DEX, but for a day or two after taking it I do notice some unexpected benefits:
    • My chronic headache disappears and I don't need to take my usual naproxen;
    • My BPH also disappears; and
    • So does my nighttime stuffy nose, for which I otherwise take a nightly nasal spray.
  • The meaning of LDH: It is a non-specific marker of "cell turnover" (cell death) which was once of some value in prognosis for a newly-diagnosed patient because it correlated inversely with survival. However, other problems such as heart disease can also give rise to high LDH, resulting in an incorrect cancer prognosis. Newer markers are much more specific to myeloma, and Dr. L wondered if LDH should even be included in the standard battery of tests any more.
  • I asked why the myeloma drives IgA and IgM (in my case) so low, and Dr L responded that the reason for that is not yet well understood.
  • Though I'm a long way from "remission" at this point, we discussed the three treatment options that seem to be available after remission is achieved: (1) Continue treatment; (2) Continue treatment at a reduced dosage or frequency; or (3) Stop treatment and wait watchfully. Dr. L confirmed that the studies which have been done thus far do not clearly indicate a survival advantage for any of the three.
Here are a few specific test results:

Test   5/29   6/26   Remarks
IgG mg/dL 1260 1450 May be a normal immune response
M-spike g/dL 1.2 1.1 I hope this is real!
L FLC mg/dL 4.25 4.03 Down is good
Calcium mg/dL 9.7 10.1 Hopefully just a normal swing

In addition, the absolute neutrophil count (ANC) dropped from 2.41 last time to 1.65 this time. This could indicate that the CC-4047 is suppressing the neutrophils, and if that happens we will have to change the test regimen. However, there is a note in the results saying that the ANC was derived in a different way this time and may not be comparable to previous results.

I'm more concerned about a remark in the CBC results saying that "toxic neutrophils" are present. I'm not quite sure, but I think it means that my body actually is dealing with a minor infection (I do have a sore nose), or maybe a muscle-repair job from the marathon that I just ran.

Perhaps I'll call Dr. L.

Friday, June 27: Dr. L says it's nothing to be worried about, probably just a normal response to a minor infection or other threat, so I won't worry.


Fruity breakfast: Gluten-free oatmeal, organic flame raisins and dried cranberries, organic strawberries, organic nectarine, blueberries, organic cashews, mango, organic pomegranate juice, organic nonfat milk.

4 comments:

  1. Hi Don,

    When your IgG goes up, is the total serum protein up too? If not, there's a good chance your IgG increased as a result of some immune response. In my case, I would see my TP results sooner and got so good that I could guess what my IgA was going to be by looking at that number!

    Are your other immunoglobulins staying the same?

    LDH -- I had a doc who said that stands for "little damned help." They still test it though. :)

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  2. Hmmm - I think that total protein would go up whether the increase in IgG was monoclonal or due to a valid immune response. In any case I don't have the rest of the electrophoresis results back yet, except the M-spike which Dr L called the lab to get.

    You are right though - during the study my TP has dropped right along with IgG.

    The other immunoglobulins are unchanged and very low. I asked Dr L what makes them go so low and she said that isn't well understood.

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  3. I always appreciate all of the details that you provide. I also found that the dex helped with headaches and a stuffy nose! That's the only nice thing I'm going to say about dex, though. :) I'm hoping to take the "watch and wait" approach someday.

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  4. Good results Don. Don't worry for the total IgG. As for the LDH it seems to me from your discussion that: if LDH is high we don't have to worry, because different causes can be at work. But if LDH is low this can be a good indicator of the state of the disease. Do you agree?
    Have a nice day!
    Sherlock

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