Palatin Technologies, Inc. Announces Positive Preclinical Data with PL-3994 for Asthma Indications

CRANBURY, N.J., June 21 /PRNewswire-FirstCall/ -- Palatin Technologies, Inc. (NYSE Amex: PTN) today announced results of preclinical studies in respiratory tissue with PL-3994.  In rat, guinea pig and human tissues, PL-3994 produced potent relaxation of isolated airway smooth muscle, indicating that PL-3994 may be a potent bronchodilator in humans.

PL-3994 is a proprietary peptide mimetic that binds and activates natriuretic peptide receptor A, a guanylate cyclase.  Naturally occurring natriuretic peptides have been evaluated for bronchodilator activity in previous clinical studies with asthmatics.  Despite positive outcomes, no commercial products have been developed in part, Palatin believes, because of the very short half-life of those molecules.  In earlier Phase 1 clinical studies conducted by Palatin, PL-3994 has been shown to have a significantly longer half-life than endogenous natriuretic peptides, with biological effects attributable to relaxation of smooth muscle seen for up to eight hours following single administrations in man.

Palatin has filed a request for a meeting with the U.S. Food & Drug Administration (FDA) to discuss an Investigational New Drug (IND) application for clinical trials with PL-3994 in asthmatic patients.  Under FDA regulations Palatin anticipates that the meeting will be held within sixty days, and assuming a favorable outcome from the meeting, an IND will be filed shortly thereafter.  Palatin plans to initiate clinical trials with PL-3994 in asthmatics as early as the fourth quarter of this calendar year.  

Commenting on today's news, Trevor Hallam, Ph.D., Palatin's Executive Vice President – Research and Development, stated, "We are excited to expand our PL-3994 program into acute severe asthma, a serious unmet medical need.  Many asthma patients that go to the emergency department with an exacerbation of symptoms have become inadequately responsive to standard bronchodilators such as Beta 2-agonists used in rescue inhalers.  Because PL-3994 causes bronchodilation through a different mechanism of action than existing bronchodilators, we are optimistic that PL-3994 will provide relief to patients for whom existing therapies do not work."

About Acute Severe Asthma

Acute severe asthma is an acute exacerbation of asthma that does not respond to standard treatments with bronchodilators.  Acute severe asthma is a life-threatening condition, with approximately 4,500 Americans dying from asthma annually.  In 2005, 1.8 million emergency department visits were for acute asthma.

About PL-3994

PL-3994 is patented in the United States and is the subject of patent applications in other countries.  Compared to endogenous natriuretic peptides, 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.

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.

About Palatin Technologies, Inc.

Palatin Technologies, Inc. is a biopharmaceutical company dedicated to the development of peptide, peptide mimetic and small molecule agonists with a focus on melanocortin and natriuretic peptide receptor systems. Palatin's internally developed drug pipeline utilizes proprietary approaches to discover potent rigid conformers from flexible peptide starting points. Palatin's strategy is to develop products and then form marketing collaborations with industry leaders in order to maximize their commercial potential.  For additional information regarding Palatin, please visit Palatin Technologies' website at www.palatin.com .

Forward-looking Statements

Statements about future expectations of Palatin Technologies, Inc., including statements about its development programs, proposed indications for its product candidates, pre-clinical activities, marketing collaborations, and all other statements in this document other than historical facts, are "forward-looking statements" within the meaning of Section 27A of the Securities Act of 1933, Section 21E of the Securities Exchange Act of 1934 and as that term is defined in the Private Securities Litigation Reform Act of 1995. Palatin intends that such forward-looking statements be subject to the safe harbors created thereby. Palatin's actual results may differ materially from those discussed in the forward-looking statements for various reasons, including, but not limited to Palatin's ability to fund development of its technology, ability to establish and successfully complete clinical trials and pre-clinical studies and the results of those trials and studies, dependence on its partners for certain development activities, need for regulatory approvals and commercial acceptance of its products, ability to protect its intellectual property, and other factors discussed in Palatin's periodic filings with the Securities and Exchange Commission. Palatin is not responsible for updating for events that occur after the date of this press release.

SOURCE Palatin Technologies, Inc.