The US Food and Drug Administration (FDAs) has granted orphan-drug designation for Ligand Pharmaceuticals' proprietary Captisol-enabled Topiramate injection for the treatment of partial onset or primary generalized tonic-clonic seizures in hospitalized epilepsy patients who are unable to take oral topiramate.

“The granting of orphan designation for Ligand’s Captisol-enabled Topiramate programme is an important step in the future of this potentially life-saving therapeutic, and should provide an additional layer of market exclusivity for the programme,” commented Matthew W Foehr, executive vice president and chief operating officer of Ligand. “In phase I trials in healthy volunteers and patients at the University of Minnesota, this product demonstrated a faster onset of action than the orally administered drug. Our goal is to find a committed partner to further progress the clinical development of this asset and add to our portfolio of fully-funded programmes.”

“An injectable formulation of Topiramate will provide patients and clinicians with an important new product that ensures continuity of therapy and offers the potential for use in acute management of several neurological disorders,” declared Jim Cloyd, Pharm. D, Lawrence C Weaver Endowed Chair in Orphan Drug Development, Professor of Experimental and Clinical Pharmacology and Director of the Center for Orphan Drug Research at the University of Minnesota-College of Pharmacy.

Orphan-drug designation is granted to drugs and biologics defined as those intended for the safe and effective treatment, diagnosis or prevention of rare diseases/ disorders that affect fewer than 200,000 people in the US, or that affect more than 200,000 persons but are not expected to recover the costs of developing and marketing a treatment drug.

Ligand is developing a proprietary Captisol-enabled formulation of Topiramate injection for the treatment of partial onset or primary generalized tonic-clonic seizures in hospitalized epilepsy patients who are unable to take oral topiramate. The formulation was initially developed at, and is exclusively licensed from, the University of Minnesota. Topiramate is sold by Janssen Pharmaceuticals, Inc. under the trade name Topamax and is currently only available as oral formulations. The Captisol-enabled Topiramate Injection formulation is designed to provide an intravenous or intramuscular option for hospitalized epilepsy patients unable to use oral topiramate. Captisol-enabled Topiramate Injection has been studied in phase I clinical trials.

Captisol is a patent-protected, chemically modified cyclodextrin with a structure designed to optimize the solubility and stability of drugs.

Ligand is a biopharmaceutical company that develops and acquires assets it believes will generate royalty revenues and, under its lean corporate cost structure, produce sustainable profitability.