By James DeGiulio --
Last week, NexBio, Inc. announced the issuance of U.S. Patent No. 7,645,448, entitled "Class of Therapeutic Protein Based Molecules." The '448 patent, issued January 12, 2010, is the company's first issued U.S. patent. The patent covers NexBio's sialidase pharmaceutical compositions, including its lead compound DAS181 (Fludase®) and methods of treating or preventing viral infection by influenza and parainfluenza with such compositions.
Fludase® (at left) is a recombinant fusion protein that inactivates sialic viral receptors on the cells of the human respiratory tract, thereby preventing all types of influenza (including H1N1) and other viruses from both infecting the human body and amplifying in already-infected individuals. Fludase® is currently undergoing a Phase II clinical trial for the treatment of community-acquired influenza. More information on the clinical trial can be found here.
Current antivirals target the virus particle and thus are limited by virus resistance. According to the patent, NexBio's technology is not limited by virus resistance because its compounds target the virus point of attachment and entry on cells, rather than the virus itself. The patent further discloses the use of these compounds to enhance gene delivery for gene therapy applications. Finally, the patent contains several examples of synthesizing sialidase proteins and corresponding functional assays.
The 21 allowed claims cover the peptides, pharmaceutical compositions, and methods of treating or preventing viral infection. Representative claims include:
1. An isolated polypeptide comprising an amino acid sequence that begins at any of the amino acids from amino acid 270 to amino acid 290 of the Actinomyces viscosus sialidase protein sequence (SEQ ID NO:12) and ends at any of the amino acids from amino acid 665 to amino acid 901 of the Actinomyces viscosus sialidase protein sequence (SEQ ID NO:12), wherein the isolated polypeptide does not comprise the sequence extending from amino acid 1 to amino acid 269 of SEQ ID NO:12 and wherein the isolated polypeptide has sialidase activity.
7. A pharmaceutical formulation comprising the isolated polypeptide of claim 1.
9. A method of treating or preventing viral infection by influenza, comprising:
applying a therapeutically effective amount of the formulation of claim 7 to epithelial cells of a subject.
James DeGiulio has a doctorate in molecular biology and genetics from Northwestern University and is a third-year law student at the Northwestern University School of Law. Dr. DeGiulio was a member of MBHB's 2009 class of summer associates, and he can be contacted at firstname.lastname@example.org.