Saturday, 1 July 2017

Randomized trial comparing 6 to 12 cycles of TMZ

Many studies have compared 6 cycles of monthly temzolomide to extended temozolomide for newly diagnosed GBM.  However, all of those studies have been retrospective in nature (they were not designed as prospective clinical trials randomizing patients to either 6 or 12 months of monthly TMZ).

A small (20 patients in each arm), but randomized trial was published recently by an Indian group.  The result was a 4 month increase in median progression-free survival in the 12 month arm, and a >8 month increase in median overall survival (15.4 months versus 23.8 months), measured from diagnosis.  

Patients in this trial were between the ages of 18 and 65, with KPS equal to or over 70. Unfortunately, there was no information (and consequently no stratification by) MGMT status, which limits the significance of the study, as the authors readily admit. "One limitation of our study is the small sample size of patients and lack of information on MGMT methylation status of patients."  However, this is the first randomized trial for newly diagnosed GBM comparing 6 cycles to 12 cycles of monthly temozolomide treatment.

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  1. Hi Stephen, based on your research to date - do you have an opinion on whether you would stop after a specific amount of monthly TMZ cycles or keep using it up to 12 cycles and on?

    I know it is likely a case by case basis as in my Dads case he is MGMT methylated so we have faith in TMZ but it gets tougher each month on him. Our thoughts our keep using it (at 6 cycles now) until images show it is no longer preventing tumor growth...?

    Here is a previous post on this blog discussing this. Curious if you have any updated opinions?

    Thanks for everything and have a great weekend.

    1. I think my decision would be based mainly on 1) MGMT status 2) tolerability and 3) whether or not treatment with a vaccine were within my financial means.

      Given that prolonged TMZ tends toward cumulative toxicity to the bone marrow and blood counts, if vaccine treatments were within my means I would probably monitor lymphocyte counts carefully and transition to immunotherapy before the counts dropped too low. If vaccines are not an option, and with MGMT methylated status I would probably continue as long as there seemed to be a benefit and reasonable tolerability, certainly up to 12 months or more.