$4.5M is chump change for MNTA, so I presume the acquired IP is tangential rather than obligatory to what MNTA is doing in FoB’s.
Based upon the 8k, Virdante's stated purpose, and the text of their one patent, I would agree that they were procured in significant part for biobetter development. But that doesn't mean that the IP is entirely tangential - in particular the one (and only) patent of Virdante is about tuning glycosylation, which is the same area in which Momenta has been churning out patents over the last 3 years in prep for biosimilars.
As for why only $4.5M - perhaps because it is only one patent. (Compared to, for instance, the 10+ that Momenta has in the same general area).
BTW - One area that I find mildly surprising with Momenta is that they are not doing more to pursue the other options that they are finding in their quest for biogenerics. If you read their patent estate it is clear that there are lots of opportunities and I am not suggesting that they should pursue them all - but, for instance, creating a small arm of the company to filter a few of these and pursue them clinically would seem worthwhile. In order to minimize loss of focus it would have to be hired with the correct people and constrained - but there is clearly a large amount of other material that they are not pursuing despite lots of finds and lots of cash.
how have ex GlycoFi employees been keeping busy at Merck? MNTA is doing things with nuts and bolts and analytics, building molecular robots. The genetic approach might not be done yet but it isn't getting anywhere.