Happy to explain may take on this.
I used the term "joint venture" to capture the fact that both Amarin and the generics want the same thing. They all want to see the largest possible US market for Vascepa. The only way that happens is if Amarin continues a full-court marketing push based on the CV indication. If Amarin pulls back those efforts, everyone loses in the long run. If Amarin continues those efforts, with the informal understanding that generics remain out of the market until it's more mature, then everyone wins in the end. It's not the long-term exclusivity that Amarin had hoped for, but it gives them several lucrative years of de facto US exclusivity while they build their ROW business. The generics enter when the market is firmly established, at which point they each capture maybe $1B+ in annual revenues for what could be many years. The alternative is they enter now and they generate maybe $100M in annual revenues, with no legal ability to grow the market through promotion of the primary growth driver (CV indication), which Amarin controls exclusively.