How long does it take to see a response to anti-myeloma therapy?

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How long

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does it take to see your response to anti-myeloma therapy?

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Most regimens work within the first month.

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So keep in mind

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if we check myeloma markers again

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those are the markers that are either in the blood or the urine.

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And we get our baseline.

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We start treatment for the patient.

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Most centers check myeloma markers in the middle of the first cycle,

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so they can get the numbers by the end of the cycle.

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The numbers take about a week to be processed.

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So the first number in the first month

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does not represent a full month of treatment.

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The labs were checked in the middle.

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So if the first number was not

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where we want it to be, I tend to give it another month

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and check in towards the end of the second month.

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This way I got a month and a half worth of treatment,

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and this year I hope to see a response.

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Keep in mind, getting a response is not the only goal we have.

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We have to get a durable response for multiple myeloma.

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also another point

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for newly diagnosed multiple myeloma,

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knock on wood, we're talking about 99% response rates.

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And I think in first relapse we're getting closer to that as well.

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So those are good numbers.

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The question is for how long that will stay like that.

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Why may it take a month before a response to treatment is detected?

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So, it's important

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to know, how to interpret the myeloma markers.

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Right. So let's take one step back.

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We talked about, M-spike, Kappa and Lambda.

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The M-spike usually is

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has two components heavy chain and light chain.

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And the heavy chain.

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Most commonly it's IgG or IgA.

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A second common it could be IgD or IgM as well.

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Those are heavy proteins that take time to be cleared through the kidneys.

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We're talking about proteins.

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We're not talking about cancer cells in the blood here.

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The chemotherapy will kill the cancer cells which will

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which means we stop the production of the new immunoglobulins.

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What let's say, for example, it's IgG.

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We stop the production of a new IgG,

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the kidneys will take time to clean

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the IgG that's already in the blood.

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That doesn't go exactly the same for light chain only myeloma.

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What's light chain only myeloma.

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Those are patients who have kappa or lambda in the blood.

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Again those are proteins in the blood.

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Those are not the active cells.

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And those kappa, Kappa or lambda, you can't have both.

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You each patient have one.

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So let's say for example a patient has kappa light chain.

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The Kappa light chain are easy to clear through the kidneys.

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So usually when we start the treatment we can even see the response

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within a week or two.

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sometimes you see it within a few days.

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That. Why why is that?

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Because we stopped the production of a new light chain,

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and the old ones are easily cleared through the kidneys.