Variable Dose Regimens for Cancer

The dose-dense philosophy in chemo treatment is to use as big a dose as the patient can handle (e.g. without the toxic side effects getting out of control.)  This was both to eradicate the observable tumor and even unobservable micro-tumors and to get rid of the cancer before it could evolve of adjust to the chemo agent.

Some experts are thinking a variable dose regimen may be preferable in some cases.

Experimenting with mice, scientists in Florida tried a variable dose protocol of chemotherapy delivery.  They started with a high dose and then quickly reduce the dose level.  This leaves both the resistant cells and a decent population of treatable cells.  This allows the treatable cells to compete with the resistant ones, so the tumor as a whole does not become resistant.  With repeated low doses, the tumor can be kept small and the major effects of cancer avoided.  The scientists did this in mice and they monitored the size of the tumor regularly with advanced imaging, which might be tough to translate into clinical care for humans.  Still, it is an encouraging finding.

Science blogger Derek Lowe says this study might promote the development of variable dosing regimens and might give medicinal chemists encouragement to pursue development of “medium-effective” drugs for eventual clinical use.