Drug companies help pay for chemotherapy in two ways: clinical trials and patient assistance programs. You can read more about clinical trials here.
Patient Assistance programs, also called indigent patient
programs, are developed to assist low-income, high-need families get started on a chemo program. Each requires an application with demonstration of need. You can start by contacting these companies:
Bristol Myers Squibb
Eli Lilly Patient Assistance Lillly Cares Program
Wyeth Pharmaceuticals Patient Assistance Program
If the patient needs medicine made by another company, research the contact information and write to them directly. Many companies have community outreach programs that have funding behind them. You can also try:
Partnership for Prescription Assistance