Is it possible that the Shareholders' Meeting is called under shareholders' request?

Yes. The Directors must call the Shareholders' Meeting when it is requested by shareholders representing at least 5% of the share capital.
However, calling a Shareholders' Meeting upon request of shareholders' cannot be made for the matters upon which, according to law, the Shareholders' Meeting will resolve on the basis of a project or report of the Board of Directors (es. financial statements)
The shareholders who request a meeting to be called must prepare a report on the proposals relating to the items to be discussed.
The Board of Directors shall make the report available to the public, together with its own evaluation, if any, at the Company's registered office, on the Company's website and on Borsa Italiana (www.borsaitaliana.it), at the time the notice calling the meeting is published.