Palatin Technologies Inc. received FDA approval for its NeutroSpec imaging agent, a seminal event in the company's history.

"I think for any emerging biotechnology company, getting the first product approved by the FDA is always a major milestone," Palatin President and CEO Carl Spana told BioWorld Today. "And this is a biologic, so it's not the easiest product to get through the agency. Even though it's an imaging agent, it required a fair amount of clinical trial work as well as CMC work to get approved. So I think it clearly indicates to the investment community and potential partners that we have an organization that can conduct clinical trials, set up and manage manufacturing, and understand the regulatory process."

Formerly called LeuTech, the radiolabeled monoclonal antibody is indicated for patients with hard-to-diagnose appendicitis. Made of a technetium-labeled anti-CD 15 monoclonal antibody, NeutroSpec is injected into the bloodstream and binds to neutrophils present at an infection site, labeling those cells with a radioactive tracer.

The result, said Cranbury, N.J.-based Palatin, is a functional image of an infection in less than an hour, a much quicker procedure than the current standard of care. In the latter case, the process of using ex vivo-labeled white blood cells takes about 12 hours to 24 hours.

"These are patients that currently are admitted to a hospital for observation," Spana said. "They receive a whole variety of tests such as CAT scans, ultrasounds and blood work-ups, but 20 percent to 25 percent of them actually have their appendix rupture while they're in the hospital waiting for appropriate treatment. So I think it has the potential to dramatically impact the 300,000 to 400,000 patients that have equivocal signs or symptoms of appendicitis every year."

Palatin's FDA submission was based on three years of clinical studies that culminated in a 203-patient Phase III trial, which showed that NeutroSpec detected appendicitis in 91 percent of positive patients and correctly predicted the absence of appendicitis in 96 percent of negative patients. The studies produced no significant adverse events.

NeutroSpec will be marketed and distributed by Mallinckrodt Imaging, a business unit of Tyco Healthcare. Spana said sales operations were already under way, following six months of preparation by St. Louis-based Mallinckrodt.

As part of the partnership, Palatin also is conducting other clinical trials to evaluate NeutroSpec's potential for indications such as osteomyelitis, an infection deep inside a bone, fever of unknown origin, post-surgical abscess, inflammatory bowel disease and pulmonary imaging.

"There aren't really many good ways of functionally imaging if a patient has an active infection," Spana said. "Our goal is, over time, to build this product into the product of first choice for imaging and detecting suspected infections."

Palatin is responsible for conducting all manufacturing and development activities, though it splits costs down the middle with Mallinckrodt for further clinical studies.

Beyond its imaging program, Palatin's lead therapeutic drug, PT-141, is in Phase II development for male and female sexual dysfunction. The company continues to work toward securing a development and marketing partner for the product.

"I think that we have a very valuable product in PT-141," Spana said, "and we are looking for a partnership that will help us get that value and allow us to participate in the upside of that."

He said the company plans to secure an agreement prior to beginning Phase III, which would come around the first half of next year.

"Operationally, we're very excited about where we are," Spana added. "The programs have come together very nicely, and it was quite a thrill and relief to see that [FDA] letter come in."

On Tuesday, Palatin's stock (AMEX:PTN) lost 18 cents to close at $4.05.