Responding to the Express Scripts' deal to promote use of a compounded alternative to its drug, Turing says physicians shouldn't prescribe the compound, since it is an unapproved and unsafe drug. But the compounder, Imprimis, says each prescription is custom-made, making it a "personalized medicine."

Pharmacy benefit manager's anti-Daraprim effort signals new direction in pricing battles, but the strategy can only be used in limited circumstances.

The agency is also poised to announce another development in its scrutiny of the drug patents listed in the FDA’s Orange Book.