This time its PAH:

https://www.cnbc.com/2024/03/26/fda-approves-merck-drug-sotatercept-for-rare-deadly-lung-condition.html

 From the Nov 18 2019 pre-market Company Conference call:

" 42.   Near Term Commercialization Steps

OK, let’s move to the final main slide here now, the near term commercialization steps. Now we kind of have a five-point approach here that we’re following and this is what we’ll be doing over the next few months. One of the key areas is the breakthrough therapy status filings, and we’ll be doing that both at the FDA and EMA. We believe we have what it takes to get that done in the next 90 to 120 days. And we’ll be moving forward in that type of direction regardless. So, SGLT2i partnering discussions, one is already initiated and key patents have already been filed. That is an exciting category. Renal partnering and discussions are moving forward. Congestive heart failure partnering discussions, already initiated. And we will continue with our orphan partnering discussions but we’ve narrowed it down to two only at this time just to stay focused. And they will be PAH and HIV only at this time. The PAH enrollment has already commenced. And the HIV funding has been derived and yet to be named yet [sic] from a US organization.  So going forward, these five areas are going to add a lot of commercial value in the very short term."