The study you link further addresses the issue with a molecule being "undruggable" because it is not orally bioavailable:
"One of the major challenges faced by PTP1B-based drug discovery efforts has been to generate orally bioavailable inhibitors of the phosphatase. In fact, the lack of oral bioavailability of active site-directed PTP inhibitors was a major factor in industry describing these enzymes as “undruggable.” Our efforts with this class of allosteric inhibitors now provide proof of concept that these challenges associated with active site-directed inhibitors of PTP1B can be overcome...The combination of PTP1B inhibition and copper chelation presented in DPM-1001 reflects a new approach to the treatment of diabetes and obesity that we hope will re-invigorate drug development efforts in this area."
To me, it looks like they will still not utilize the full potential of the drug. But whatever can get DPM-1001 into production, I am for. (Group buy/synthesis anyone? ;)) It looks like their secondary observations of regeneration/restoration might be closer to the true potential for this molecule:
"In studying mice, DPM-1001 reduced liver complications, including enlarged cell size, irregular shape and arrangement in liver tissue."
https://www.cshl.edu/progress-toward-improved-wilsons-diseas...