I know of some people that are on long term Erbitux for a year for palliative care, and don't know of any about any maximum allowed chemo, but most use trial based therapies, may switch to another to avoid developing a resistance or when no improvement is seen. Some targeted therapies need to be long term in the palliative setting, like 6 months to a year for benefit, some chemos are given in cycles, then stopped, and restarted again.

I had Erbitux with radiation, for 6 weeks, but that was for curative intent. The first week is a loading dose, based in your weight, about 470mg for me, along with an infusion of Benadryl, a Tylenol, Hydration. After that were weekly infusions around 250 mg. The first infusion they monitor you closely since a small percentage have a severe allergic reaction, heart failure from it. The worst part of Erbitux is the rash, which can be severe, and the itching, skin dryness drove me crazy. They will give you antibiotics once the rash appears, and the best to use they say is Minocycline. I had 50mg capsules 3x a day.

Good luck.