NIH approved our request to name a substitute PI a couple of years
ago upon the death of the original PI.  Write to the program director
with a copy to the grants manager.  Other than the obvious direct
involvement with the project which it seems you will be able to
demonstrate, the key is the substitute's ability to direct the work.
Be specific about ongoing experiments and the substitute's direction
of them.

If NIH approves the request, the extension can be effected internally
under the expanded authorities.

According to the PHS Grants Policy Statement, NIH requests
notification as soon as possible but not later than 30 days before
the PI withdraws from the project or devotes substantially less
effort than was anticipated.

Feel free to call if you like.

Catharine Crea
Office of Research Administration
New York Medical College
xxxxxx@nymc.edu
(914)993-4480
New York Medical College