No brand manufacturers plan to market generic versions of their own product, at least not until the patent expires. And why would they? As long as the branded version enjoys patent protection, marketing a cut-rate product would eat away profit margin during the years when a drug makes the most money.
Contrary to myth, Paragraph IV certifications are not reserved only for blockbusters or high-volume primary care products. Three products under recent Paragraph IV challenges had sales of less than $50 million.