Invalidity dossier
US 5556940
Parathyroid hormone analogues for the treatment of osteoporosis
Current assignee: National Research Council Canada
Added 9/23/2026, 4:53:49 PM
Active provider: DeepSeek · deepseek-flash
Patent summary
Title, assignee, inventors, filing/issue dates, abstract, and a plain-language overview of the claims.
US5556940A — Patent Overview
Title: Parathyroid hormone analogues for the treatment of osteoporosis
Patent number: US5556940A
Application number: US08/262,495
Assignee: National Research Council of Canada
Inventors: Gordon E. Willick; James F. Whitfield; Witold Surewicz; Wing L. Sung; Witold Neugebauer
Priority/filing date: 1994-06-20
Publication (grant) date: 1996-09-17
Legal status (as listed): Expired – Lifetime; anticipated expiration 2014-06-20
Purpose. The invention concerns analogues of human parathyroid hormone (hPTH) said to be effective in treating osteoporosis — reversing bone loss and increasing bone mass and density "specifically without undesirable side effects." Native PTH is noted as effective for diminishing bone loss but as possibly causing undesired effects such as hypertension and smooth muscle relaxation.
Plain-language scope. The patent describes hPTH analogues ending in a carboxyl-terminal amide, including hPTH-(1-28)-NH₂, hPTH-(1-29)-NH₂, hPTH-(1-30)-NH₂ and hPTH-(1-31)-NH₂. A central finding is that replacing Lys²⁷ with Leu increases receptor binding and cAMPase stimulation, with maximum activity only in the amide form; claimed analogues span [Leu²⁷]-hPTH-(1-28)-NH₂ to [Leu²⁷]-hPTH-(1-33)-NH₂. Also described are cyclic lactam analogues along the helix's polar face, e.g. cyclo(Lys²⁶-Asp³⁰)[Leu²⁷]-hPTH-(1-34)-NH₂ and cyclo(Lys²⁷-Asp³⁰)-hPTH-(1-34)-NH₂. Methods include solid-phase synthesis (Fmoc chemistry), adenylyl cyclase assays on ROS 17/2 cells, and ovariectomized-rat bone mass testing. Administration is described as parenteral, topical, rectal or by inhalation to warm-blooded mammals, particularly humans.
Not established by this excerpt. The supplied text is explicitly marked as an excerpt with omitted portions. It therefore does not provide complete claim language or claim count, the full specification, working examples in full, complete assay data, dosage regimens, or the exact scope of coverage. It also does not establish priority-chain details beyond those listed, the CA2126299C counterpart's contents, or the subject matter of US6110892A and US6541450B1, which are merely listed as later filings.
Source: https://patents.google.com/patent/[US5556940](/patent/US5556940)/en
Generated 10/1/2026, 9:44:03 PM
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Assignment history
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Prior art
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Obviousness
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