Insulin and pharmacy benefit management company executives testified before the Senate Health, Education, Labor and Pensions Committee this week in Washington in preparation for a vote on PBM legislation.

Although Horizon says it now has 20 drugs under development, in its 15 years of existence it has yet to license a product it invented.

Eli Lilly's announcement that it is capping the cost of insulin at $35 a month also casts light on pharmacy benefit managers at a time when Congress has shifted its focus on them.

The FDA's accelerated approval is usually based on a "surrogate marker" of effectiveness.