Given their value to the company, I would imagine they would be holding back any positive GFR data only because of an embargo or a request from academics involved in BETonMACE who want to submit a paper to a top journal like NEJM or submit it for presentation at a top meeting. But I find it puzzling that DM has not made any reference to any plans to present the kidney data anywhere or publish them (unless I have miussed it).
An alterantive might be that the data form the basis of a patent application, which might also make them very cautious about disclosing details in the public domain.