WASHINGTON _ In an active day for diagnostic approvals, theFDA Tuesday authorized three new tests that will screen patients forosteoporosis, prostate cancer and heart attack-causing blood clots.

Cytogen Corp. was cleared to market its prostate cancer imagingproduct, ProstaScint. The product, a radiolabeled monoclonalantibody, will be on the market in early 1997 to help physiciansidentify prostate cancer spread.

The FDA approved the intravenous imaging agent, ProstaScint, fortwo specific types of prostate cancer patients: those with newlydiagnosed prostate cancer which is thought to be localized and thosewho have had their prostates removed due to cancer and thephysician suspects the cancer may have recurred.

"ProstaScint should result in earlier detection of prostate cancermetastases," said Robert Maguire, vice president for Medical Affairsfor the Princeton, N.J., company. "And, early detection can meanmore appropriate therapy for patients and better survival."

Prostate cancer will strike more than 300,000 American men thisyear, according to American Cancer Society estimates and more than40,000 men will die this year of the same disease.

While prostate specific antigen testing can help identify men whomay have the cancer as well as identifying those who haverecurrences despite the surgical removal of their prostates, physicianscurrently have no way of locating to what part of the body the cancerhas spread or recurred. Therefore, they have little information whenchoosing the appropriate therapy for their patients.

ProstaScint works by attaching an indium-111 radioactive label to amonoclonal antibody against the Prostate Specific Membrane antigen(PSMA) _ a protein found in the membrane of prostate cells. WhilePSMA is present in normal prostate cells, prostate cancer cellsproduce more of the protein and prostate cancer cells that havemetastasized make even more. As a result, metastatic prostate canceroffers the radiolabeled antibody more binding sites. These cancersthen light up on whole-body scans that are similar to bone scans.

"This is a simple idea," said Maguire. "But, it is a little tricky toactually perform the scan and interpret the results. That is why ourlabeling will reflect that physicians need specific training to use themethod."

While the company has yet to determine final pricing for ProstaScint,they estimate the cost of the entire procedure at around $2,000.

Cytogen's (NASDAQ:CYTO) stock was up $0.625 on the newsTuesday to close at $5.687.

TpP Tests For Levels Of Fibrin Polymers

American Biogenetic Systems (ABS) Inc., also received FDAapproval to market their Thrombus Precursor Protein (TpP) test. Thetest is expected to gain widespread usage by physicians because itcan detect stroke and heart attack-causing blood clots before theyhave become deadly.

"We are very pleased about the approval of the TpP test," saidLeonard Suroff, director of shareholder relations at the Copiague,N.Y. company. "It has a large number of indications."

The test detects the levels of fibrin polymers in a patient's blood.When those polymers become elevated, a person is at risk for heartattack, deep vein thrombosis, disseminated intravascular coagulationand stroke. Physicians can use the test to decide if a patient needs tostart anti-coagulation therapy as well as to monitor patients who areon anti-coagulation therapy.

ABS is producing the product in collaboration with AbbottLaboratories, of Abbott Park, Ill., F. Hoffman-La Roche Ltd., ofBasel, Switzerland, and Gull Laboratories Inc., of Salt Lake City.The companies have not yet set a date for when the test will becomeavailable.

ABS stock (NASDAQ:MABXA) closed Tuesday at $5.187, down$0.313.

Test Identifies Patients At Risk Of Osteoporosis

Also approved for marketing is an automated diagnostic test forosteoporosis. The diagnostic, known as ACS:Dpd, is a collaborativeeffort between Metra-Biosystems Inc., of Mountain View, Calif., andChiron Diagnostics, of Emeryville, Calif.

"In combination with measurements of bone density, ACS:Dpd canhelp physicians better treat patients with osteoporosis," said KurtAmundson, chief financial officer and vice president for Metra.

Unlike steel girders that support buildings, bone is constantlyremodeling itself _ breaking down old bone and adding new bone.When the breakdown process of resorption outpaces bone rebuilding,osteoporosis can result.

The ACS:Dpd uses immunoassay techniques to measure the rate ofresorption to help physicians measure whether a patient is at risk forosteoporosis or if a therapy is working.

Metra-Biosystems developed the immunoassay using their Pyrilinks-D technology and Chiron added automation to the collaboration withtheir ACS:180 automated immunoassay system.

"The automated nature of the ACS:Dpd should make the test muchmore available for physicians," Amundson said.

ACS:Dpd automatically measures how much deoxypyridinoline(DpD) crosslinks a patient is excreting in his or her urine. Becausethese crosslinks give bones their strength, measuring the amountexcreted in the urine can give a good indication of the rate of boneresorption.

Metra-Biosystems' stock (NASDAQ:MTRA) lost $0.25, endingTuesday at $5.626. n

-- Lisa Seachrist Washington Editor

(c) 1997 American Health Consultants. All rights reserved.