Phase1 may demonstrate target engagement, page-19

This 2016 work is from scientists from several institutions in Iran. I guess there are good guys there too. I have seen work in the past which demonstrated metformin triggering the regrowth of neurons, in rats.
[4. CONCLUSION Consumption of Met results in neuroprotective effect in CA1 subfield. However, the consumption of Met does not completely reverse neuronal loss in Aβ-induced model of AD. Therefore, we suppose that pretreatment of Met by a neuroprotecctive effect can prevent from Aβ-induced cell death in pyramidal neurons of high risk rats with HFD consumption. Furthermore, these findings present a unique opportunity for prevention and treatment of AD in human.]
https://pdfs.semanticscholar.org/ba40/9fb6d58740502648cd7070110e3f40b3b850.pdf
Now with Metformin generic, I guess there are possibilities of combinations.