It does not look to be possible in AppScript, but is possible in ModScript even though it does not appear in the documentation.  See this article.  

Alternatively, you can make JSON calls or even SOAP calls from ModScript that can transition an item.

Thank you David Goodale  , We are using SBM 11.4. Does your suggestion work with this version? Additionally, can you provide me with an example of JSON calls? I have the sbm_json_api_guide.pdf.

Mohammad Alsharayri SBM 11.4 modscript can make REST calls.  This link will give an example of calling out to a REST service from modscript.  There is also link on the bottom of this article that will take you to the table of contents for the modscript examples.

 SBM ModScript, Part 8 - REST Callouts 

Thank you David Goodale