Patent Office Upholds Shire’s Patent for Hunter Syndrome Enzyme Replacement Therapy

The PTO’s Patent Trial and Appeal Board upheld Shire’s patent claims — following a challenge from Green Cross — over methods for the manufacture of Elaprase (idursulfase), an enzyme replacement therapy for Hunter syndrome.

Green Cross charged that Shire’s 2015 patent for the therapy was obvious to those trained in the profession, citing its own 2014 patent for the preparation of the enzyme — the protein iduronate-2-sulfatase, or I2S, which carries a genetic deficiency in Hunter syndrome patients.

Green Cross said its preparation method differs from Elaprase’s and offers superior safety and efficacy.

The company argued the 2014 patent, in addition to available guidance documents and scientific papers, reflected the general knowledge of the time.