Just because a drug has received FDA approval does not mean that it is available in the marketplace. But, why would a company go through all the trouble and expense getting FDA approval for drug, only to not launch it?
There are strategic reasons why a company a company go through the trouble of getting approval, yet not launch a drug, and there are ways to track indicators of when an approved drug will be available on the market.
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Case Study: Apixaban
Apixaban was first approved as Eliquis by Bristol Myers Squibb in 2012. It was protected by three patents:
- Patent 6,413,980, describing “Nitrogen containing heterobicycles as factor Xa inhibitors,” with an expiration date of December 22nd, 2019.
- Patent 6,967,208, describing “Lactam-containing compounds and derivatives thereof as factor Xa inhibitors,” with an expiration date of November 11th, 2026.
- Patent 9,326,945, describing “Apixaban formulations,” with an expiration date of February 24th, 2031.
The ‘980 and ‘208 patents both had compound claims, which identifies them as likely blocking patents. The formulation focus in the ‘945 patent implies that competitors may be able to work around it.
Litigation related to Apixaban (see Figure 1) indicates that all three patents faced challenges. The general mechanism of drug patent litigation is that a would-be generic entrant must file an ‘approvable’ generic drug application (an Abbreviated New Drug Application, or NDA), with the FDA. This application must detail the patents protecting the drug and how the generic entrant intends to address them.
For example, a generic company can state that they intend to wait until all patents expire before they launch, or they can assert that the active patents are invalid or would not be infringed. If the patent holder disagrees with the invalidity/non-infringement statements, then they can sue the generic entrant and also trigger a 30-month delay in FDA approval of the generic application.
On December 23rd, 2019, Micro Labs and Mylan obtained generic approvals for apixaban (see Figure 2). However, the drug was not available on the market.
Why?
It appears that this was a case of avoiding an ‘at-risk’ launch. Without access to the original ANDA (they’re proprietary) one can only use the available information to assert its contents. BMS’s lawsuit against Mylan was initated on April 5th, 2017. A 30-month delay applied to this case would have expired on October 5th, 2019, at which point Mylan would have been able to obtain an ANDA approval and launch ‘at risk’ even if the lawsuit were still in process.
BMS’ patent infringement case against Mylan was dismissed in 2018, but presumably the ‘980 patent was still blocking approval of the ANDA. Once that patent expired on December 22nd 2019, the FDA would have been able to move forward with the application, which is in line with the December 23rd approval.
But, Mylan and Micro Labs didn’t launch. While later news reports announced a settlement keeping them off the market, there are other indicators which can be used.
Tracking the supply chain
For a drug to be distributed and sold, it needs an National Drug Code (NDC) number. NDCs were designed for inventory management and reimbursement, and they play a central role in distribution and sales.
Looking at the NDCs for apixaban (Figure 3), one can see that at the time of publication only BMS has NDCs listed for the drug.
Other upstream factors, such as drug master files and API manufacturer listings are other complementary indicators of actual drug launch, but the simplest way to see if an FDA approved drug has actually launched on the market is to track the NDC codes.
