(19-March-2005) Palatin Technologies Inc. and King Pharmaceuticals Inc. on Friday said men taking their experimental impotence treatment in combination with Pfizer Inc.'s Viagra in a small clinical trial had significantly longer-lasting erections than those who only took Viagra.
 

All 32 patients in the trial had erectile dysfunction problems and received Viagra tablets at doses of either 50 milligrams or 100 milligrams. Some of the men also received one of two doses of Palatin's and King's nasally-administered medicine, called PT-141.


Patient erections were then monitored for 6 hours using a special device, in the absence of visual sexual stimulation.


"The duration of erectile activity measured after co-administration of each combination of PT-141 was significantly enhanced compared to that observed with the relevant dose of Viagra alone," Palatin and King said in a release.


The effect was statistically significant in three of the four comparisons, and combined use of PT-141 and Viagra did not cause any significant health problems, the companies said.


The companies said their drug works through a different mechanism than Viagra and could therefore have safety advantages over the Pfizer drug, which cannot be used by men taking nitrate-based heart medicines.


PT-141 is the first in a new class of sexual-dysfunction medicines that stimulate receptors to a protein called melanocortin. It is being studied in mid-stage trials among men and women.


Viagra and similar treatments, including Cialis sold by Eli Lilly and Icos Corp., work by blocking an enzyme called PDE-5.


PT-141 is the most important experimental drug for Palatin, which is based in Cranbury, New Jersey, and lost $2.3 million in its second fiscal quarter ended Dec. 31.


Shares of Palatin rose 15 cents, or 6.8 percent, to $2.37 in early trade on the American Stock Exchange. Shares of King fell 9 cents, or 1 percent, to $9.27 on the New York Stock Exchange .


King, which makes popular blood pressure medicine Altace and widely used muscle relaxant Skelaxin, on Thursday reported its fourth-quarter earnings fell 50 percent to $14.7 million as it reduced wholesale inventories of its drugs.