My take

Following on no partnership news from Mallinckrodt and trying to understand their recent acquisition of Ocera Therapeutics:
http://www.mallinckrodt.com/about/news-and-media/2313719
OCR-002 has been granted both FDA Orphan Drug designation and Fast Track status and Mesoblast's GvHD also has been granted Fast Track status. It seems to me that MNK views OCR-002 as a much bigger opportunity ($5-$7 billion USD) compared to Mesoblast's GvHD in terms of dollars.
Does that explain why there has been no partnership (yet) for GvHD?

With regards to CLBP, there has been no fast track or RMAT (yet) and that is probably why no partnership (yet). Mallinckrodt (and Mesoblast) most likely expected a fast track or RMAT designation before their negotiation agreement expired in 09/2017.  

For what it's worth, it's important to note the comments at the 9:35 mark where he says "we clearly believe that the RMAT designation for our back pain product should meet the definition" and also at the 10:45 mark:


I really wish both SI and Michael Schuster should hand over their respective roles to better people, in terms of being pounding the FDA doors and in terms of dealing with potential partners, respectively. I remember @Paulc8166 asking me if the fact that Mesoblast being an Australian company is the reason for it not being taken seriously in the US markets. At the time, I responded that it can't be because of the location. Now, I believe, perhaps it's because of the lack of effort and savvy from SI. It might also be due to him and Schuster being too much emotionally tied to the co, in the process blinding themselves to basic business sense.