print OUT join ";", map {${$_}[1],${$_}[2]} grep { ${$_}[0] eq "EMBL" } $entry->DRs->elements(); 

INPUT :
DR EMBL;ABC;DEF;-.
DR EMBL;GHI;JKL;-
DR PIR;MNO;PQR;-

OUTPUT :
EMBL ABC;DEF;GHI;JKL;