Bone Cancer Therapy Project Funding Awarded to Brookhaven National Laboratory for Diatide-Licensed Product.

LONDONDERRY, N.H.--(BW HealthWire)--June 24, 1999--

At the Westergaard Conference in New York today, the President and CEO of Diatide, Inc. (Nasdaq:DITI) announced that the Department of Energy has selected Brookhaven National Laboratory (BNL) as the recipient of a total of $750,000 over three years to develop Stanamet(TM) (also known as Tin-117m DTPA) technology for the treatment of bone cancer through a Cooperative Research and Development Agreement (CRADA) involving BNL and Diatide. Diatide is already developing this technology as a cancer pain relief therapy. The Company exclusively licensed the technology for this application from Brookhaven Science Associates, the operator of Brookhaven National Laboratory (Brookhaven, NY) for the U.S. Department of Energy, in 1995.

"This project was one of only 17 research collaborations that the U.S. Department of Energy's Office of Science selected for funding at its National Laboratories under its Laboratory Technology Research Program," said Suresh C. Srivastava, Ph.D. and Senior Scientist at Brookhaven National Laboratory. "In awarding the funding, the Department of Energy is supporting the development of a potentially significant advance towards treating patients in addition to alleviating their pain from bone metastases. We believe that Stanamet can be an ideal isotope for treating cancer of, or in, the bone because it is taken up avidly by the bone, yet its radiation has a short range so that bone marrow is spared from the damaging irradiation associated with other radioisotopes."

In Phase I and II studies conducted by Brookhaven scientists, Stanamet has shown the potential to deposit a high concentration of radioactivity on cancer-affected bone mass, without causing intolerable levels of toxicity to the bone marrow. That is because Stanamet, with its unique radioactive form,

emits low-energy electrons resulting in less radiation exposure to the bone marrow and fewer blood-cell depleting side effects than other radioisotopes. Diatide and Brookhaven believe that the low-energy radiation attribute of Stanamet may make it useful as a potential cancer treatment.

Richard T. Dean, Ph.D., President and CEO of Diatide, said, "We look forward to testing Stanamet as a cancer treatment while simultaneously advancing the product's development as a treatment for bone pain associated with cancer."

Presently, Diatide is conducting a Phase II study on the use of Stanamet for the relief of pain that arises when cancers metastasize to the bone. The Company believes that the short-range, low-energy radiation makes Stanamet a more practical pain reliever, compared with narcotics and the two high-energy radiation products currently on the market, Metastron(R) (strontium-89) and Quadramet(R) (samarium-153).

Diatide, based in New Hampshire, is a specialty pharmaceutical company developing a novel line of disease-specific imaging and therapeutic agents - Techtides(R) and Theratides(TM) - as pharmaceuticals with commercial and medical promise. Diatide has applied its patented technologies in the areas of peptide engineering and radiolabeling chemistry to produce a number of small molecules that bind with high affinity and specificity to targets on diseased tissue and to which a radioisotope can be attached for imaging or therapeutic purposes.

Diatide's first product, AcuTect(TM) for the imaging of acute deep vein thrombosis (blood clots) in the legs, received marketing approval, after a priority review, from the FDA in September 1998. The product was launched in October 1998. Diatide's second product, NeoTect(TM) for the imaging of lung cancer, received an approvable letter in December 1998 and is awaiting FDA approval. NeoTect(TM) is the prototype for Diatide's "Find, Fight, and Follow" strategy in oncology. As part of this strategy, the Company is developing a drug for treating lung and breast cancer. This compound, Diatide's first Theratide(TM) , consists of a targeting peptide similar to that in NeoTect(TM) but labeled with the therapeutic beta-emitting radioisotope, rhenium-188.

For NeoTect(TM) and AcuTect(TM) , Diatide has a marketing and sales collaboration with Nycomed Amersham. Diatide is actively seeking corporate alliances for its cancer therapy products and other imaging products in its pipeline. The Company owns 42 issued U.S. patents and 48 granted foreign patents, and has licensed rights to seven additional U.S. patents and their foreign counterparts.

More information on Diatide can be obtained from its web site, http://www.diatide.com.

This press release contains forward-looking statements that involve a number of risks and uncertainties. For this purpose, any statements contained herein that are not statements of historical fact may be deemed to be forward-looking statements. Without limiting the foregoing, the words "believes," "anticipates," "plans," "expects," "intends," and similar expressions are intended to identify forward-looking statements. Important factors that could cause actual results to differ materially from those indicated by such forward-looking statements are set forth under the caption "Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations - Risk Factors" ("Risk Factors") in the Company's Annual Report on Form 10-K for the year ended December 31, 1998 which is on file with the Securities and Exchange Commission. These Certain Factors are incorporated herein by reference. As more fully described in the Certain Factors, the Company's potential products (other than AcuTect ) are all still in development; there can be no assurance that the Company's potential products will demonstrate the safety, efficacy, and cost attributes currently expected by the Company; there can be no assurance as to when the FDA will complete its review of the NDA for NeoTect (P829); there can be no assurance that the Company will receive regulatory approvals to commence or continue clinical trials of product candidates, or to market any products, including NeoTect ; and, there can be no assurance that AcuTect , NeoTect , or the Company's other potential products will be commercially successful, or accepted by the medical community or third-party payors, or that technologies, patents and proposed products of other companies will not render the Company's products obsolete or noncompetitive.