Puerto Rico ? A U.S. federal grand jury indicted seven people in a case where terminally ill cancer patients allegedly were injected with a bogus cure made from the patients’ own blood, the U.S. attorney’s office in San Juan announced Thursday.

Four Puerto Ricans, including two doctors and a businessman, were arrested Thursday in the U.S. Caribbean territory, and a Uruguayan doctor was arrested in Florida, the prosecutor’s office said in a statement. Two Uruguayan doctors were expected to be extradited from their country.

The suspects allegedly sold some 50 people a fake cancer cure known as Pharma Blood, which consisted of blood that was extracted from the patient then boiled, frozen and processed, before it was injected back into the patient.

Federal prosecutor Jose Ruiz said the suspects charged $8,000 to $12,900 for each treatment and told the patients it would keep the cancer from spreading.

Authorities said most of the patients have died after relying on the phony cure instead of FDA-approved treatments such as radiotherapy or chemotherapy.