August 6, 2009 – Palatin Technologies Inc. said this week it received a notice of allowance from the U.S. Patent and Trademark Office covering a family of cyclic compounds that bind to natriuretic peptide receptor A (NPRA), including PL-3994, which is Palatin's lead heart failure drug candidate.
Patent application number 11/694,260, is titled "Cyclic Natriuretic Peptide Constructs." Palatin expects the patent will issue in the second half of 2009 and its 20-year term would expire in 2027.
"We are extremely pleased to be getting this patent coverage," said Palatin President and CEO Carl Spana. "PL-3994 and related compounds are first-in-class peptide mimetics with extended half-lives and favorable pharmacokinetic properties. These are the only drugs we are aware of that bind to NPRA and are suitable for subcutaneous administration, with the possibility of once-daily administration."
PL-3994 and the related family of cyclic compounds were discovered entirely in-house and are owned by Palatin. In addition to the allowed U.S. patent application, Palatin has applications pending in selected countries outside the United States and additional U.S. applications covering related compounds.
Palatin has completed two clinical trials with PL-3994, a phase 1 trial in healthy volunteers and a phase 2a trial in patients with controlled hypertension. PL-3994 produced dose-related decreases in blood pressure, increases in plasma cGMP (cyclic guanosine monophosphate), a natural messenger nucleotide, and increases in urine volume and sodium excretion. There were no serious or severe adverse events, the company said.
PL-3994 incorporates a new and proprietary amino acid mimetic developed by scientists at Palatin. PL-3994 has an extended half-life, with reduced affinity for natriuretic peptide clearance receptors and increased resistance to neutral endopeptidase, an endogenous enzyme that degrades natriuretic peptides. The result is a drug candidate with improved pharmacokinetic and pharmacodynamic properties.
For more information: www.palatin.com