Upping the dosage of Tarceva - 1248075

apra
Posts:142

As I had mentioned earlier, my husband was started on 100mg of Tarceva. This is his 9th day today and by God's grace he has not suffered any side effects so far.

However I am very happy to report that his symptoms have decreased considerably. His respiration ha improved, his bone pains have minimised to the extent that he is not on pain meds anymore. The Samarium radio therapy has also been deferred as th bone pain is no longer an issue:)

Apart from resolving of symptoms we have no empirical evidence on the disease position, but I hope this men's the disease is also responding.

My questin is in such a scenarion is dosage increase more beneficial?

His mutation tests have still not come. It may take another 10 days as we were told the hospital gave the tissue to the Quest lab only yesterday :( We were expecting the results on Monday, but the hospital kept the tissue and the cell block for more than 10 days without handing over to the lab.

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JimC
Posts: 2753

Hi Apra,

That's great to hear that your husband's symptoms have decreased. That's a pretty good indication that Tarceva is having an effect. Unfortunately no one knows what the optimal dosage would be. When the standard dosage (in this case 150mg) is set as a result of trials which seek to determine the highest dosage tolerable by a majority of patients, rather than the lowest dosage that is effective. The thinking is that you want to be sure the drug is effective. If your husband increases his dosage, there is no way to know whether that dosage is more effective than the current 100mg, especially since he has not yet had a scan to judge the effect. I would think it would make sense to wait at least until the EGFR results return, or even until the first scan, to make the decision. If he has an activating EGFR mutation, there's a good chance that he doesn't need the full 150mg dose to be effective. If not, but his symptoms continue to improve, it seems pretty clear that Tarceva is working well.

JimC
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apra
Posts: 142

Thank you Jim for your input. Yes I think we will have to wait for the mutation test results.

As you have pointed out, the trials did not test to see the minimum dosage under which the drug would work, just the maximum tolerable limit.

I was thinking that if the cancer is responding to Tarceva, then why not throw more of it at the beast.

Dr West
Posts: 4735

The reason is because Tarceva (erlotinib) is meant to be taken on a daily basis, and it is only useful if someone can safely tolerate it. If a higher dose adds side effects but doesn't improve the efficacy of the treatment, increasing the dose can just make things worse, not better.

-Dr. West

apra
Posts: 142

To increase or not to increase is the dilemma that we are on now. He is totally side effect free at the moment, for which we are praising God so much.

Dr. West, reading through the experience of others I realise that what you have pointed out is very true. If a drug is too toxic for you, you will not be able to take it at all.

I think we should not rock the boat by taking a higher dose at this juncture. Every individual is different, so maybe my husband's threshold is 100mg.

When he was on Alimta, he was tolerating 700mg which was keeping his disease stable, but the momen he standard dosage of 900mg was given he started to deteriorate and had massive progression. So I guess more of a good thing is no necessarily better.

Thank you everyone for your inputs and concern.

apra
Posts: 142

Janine,

Thank you for your good wishes. We are praying he does well for a very long while.
As usual, you will notice that I have tied myself into a knot regarding the issue of upping the dosage. To up or not to up is the question. He has taken the last 100mg tablet today, the 10th one. We are seriously thinking of continuing with this dosage instead of the 150 mg that is waiting for us in the drawer.

Since this is very much uncharted territory, we are desperately looking for signs and signals.

certain spring
Posts: 762

I wonder if you need more time to see how your husband is responding - in terms of what shows up on a scan, in terms of side-effects, and of course to find out the mutation test results - before deciding.
Everyone is different, but for what it is worth I didn't get any side-effects for ten days, and wondered what all the fuss was about.