As noted in Section 3.2.13, we estimate market size for each indication based on 2011 sales data obtained from IMS Health in three different ways:
- Estimate 1: Total sales of antibacterial drugs that are in the formulation of interest (i.e., oral or IV) labeled to treat the indication.
- Estimate 2: Total sales of all antibacterial drugs in Estimate 1, plus other formulations of the antibacterial drugs in Estimate 1, plus any other antibacterial drugs (in any formulation) approved to treat the indication.
- Estimate 3: Total sales of all antibacterial drugs in Estimate 2 plus any antibacterial drugs that compete with antibacterial drugs in Estimate 2 for treating other indications (i.e., if a drug included in Estimate 2 is also used to treat another indication, all other drugs used to treat that other indication are added to the total sales calculation for this final estimate). Due to the extent of overlap among drugs used to treat these indications, Estimate 3 is the same across all indications considered ($9.23 billion).
The three estimates are intended to reflect differing visions of drug manufacturers as they consider potential market size. The smallest estimate is for the drug and formulation specifically under development, which represents the most conservative or narrowly defined market vision. The medium estimate represents the larger potential market for treating the same indications, but also reflects the possibility that the NME can be formulated for oral administration as well. The largest estimate represents all potential antibacterial drugs with which the NME might compete if it can also be approved to treat other indications. More details on the drugs included in each market size estimate are provided in the following sections. It should be noted that some of the drugs used in generating these estimates may have been discontinued since the time for the data collection.