The approval of the generic form of a biotechnology drug rekindled fierce debate within the pharmaceutical industry and Washington over how federal regulators should handle similar applications as patents expire on billions of dollars worth of drugs.

The high cost of biotechnology medicines — some fetch more than $100,000 annually per patient — have made them an attractive target for generic manufacturers. But Food and Drug Administration officials say they don’t have the authority to approve biotech knockoffs and insisted its approval Tuesday was of a “follow-on protein product” rather than a generic drug.