Biomarin Pharmaceutical Inc., of San Rafael, Calif., said it enrolled the first patient in a phase I/II trial of BMN 250, its enzyme replacement therapy using a fusion of recombinant human alpha-N-acetyglucosaminidase with a peptide derived from insulin-like growth factor 2, to treat Sanfilippo B syndrome, also known as mucopolysaccharidosis IIIB (MPS IIIB).