The relevant EASA requirement for entry to a first MPA type rating course is for the applicant to "hold a multi-engine IR(A)". In EASA-speak, 'current' and 'valid' mean the same thing and you do not 'hold' an IR unless it is valid.
For second and subsequent ratings it is only necessary to hold a multi-engine IR(A) for issue of the rating, not for entry to the course.