Zelos Therapeutics' Ostabolin-C(TM) Increases Bone Mineral Density in Phase 2 Osteoporosis Trial.

WEST CONSHOHOCKEN, Pa. -- Zelos Therapeutics, Inc., today announced top-line results from a Phase 2 study of its novel parathyroid hormone (PTH) analogue, Ostabolin-C[TM], in postmenopausal women with osteoporosis. Ostabolin-C is cyclic PTH (1-31), a proprietary PTH analogue that has demonstrated strong bone building activity in preclinical studies and is in late stage clinical development for the treatment of osteoporosis.

Ostabolin-C met the primary objective of this 4 month study by demonstrating a highly statistically significant, dose responsive increase in mean lumbar spine bone mineral density, that reached 5.2% at the highest dose tested.

"We are greatly encouraged to see this impressive increase in bone mineral density after only four months of treatment with Ostabolin-C," commented Brian MacDonald, MB, ChB, PhD, Chief Executive Officer of Zelos. "Ostabolin-C has the potential to be uniquely positioned among osteoporosis treatments as an agent that can rapidly increase bone mass. Bone building therapies such as this are increasingly needed for the large and growing number of people who have already lost large amounts of bone as a result of osteoporosis and are at high and imminent risk of sustaining a fracture."

Ostabolin-C was generally well tolerated. The most common adverse events in the study were similar to those seen with other PTH analogs, namely nausea and headache. Mild hypercalcemia was observed at the highest dose tested, but at other doses that also demonstrated strong bone building activity, the incidence of hypercalcemia was similar to the placebo treated group. Additional results from the study have been submitted for presentation at an upcoming medical meeting.

About the Phase 2 Study of Ostabolin-C[TM]

The Phase 2 double blind, placebo controlled, dose ranging study enrolled 261 postmenopausal women with moderate osteoporosis into five dose groups (placebo, 5, 10, 20 and 30 ug by daily subcutaneous injection). Treatment was continued for 4 months. The primary endpoint of the study was the percentage change in lumbar spine bone mineral density. All study subjects were offered the opportunity to continue treatment in an 8 month blinded extension to this study to allow the evaluation of 12 months of continuous treatment with Ostabolin-C. Over 75% of eligible study subjects have participated in this blinded extension study. Zelos also announced today that all treatment visits in the extension study have been completed. Data from the full 12 month treatment period will be available in the second quarter this year.

About Ostabolin-C[TM]

Ostabolin-C, a cyclic 31 amino acid PTH analogue, is a bone formation agent designed to improve upon the safety and efficacy of current therapies in the large and rapidly growing osteoporosis market. Preclinical and Phase 1 studies have shown that Ostabolin-C stimulates significant bone formation with little to no stimulation of bone resorption. Due to the minimized bone resorption, Ostabolin-C has the potential for enhanced efficacy but with reduced potential to cause hypercalcemia, a common side effect of current PTH therapies. With this profile, Ostabolin-C may become a best-in-class compound in the growing PTH market and a leading therapy for the treatment of osteoporosis.

About Zelos Therapeutics, Inc.

Zelos Therapeutics, Inc. is a privately held biopharmaceutical company developing novel therapies for patients suffering from conditions responsive to PTH-based therapeutics. The Company is in late-stage clinical development with Ostabolin-C[TM], a PTH analogue designed to improve upon the safety and efficacy of current therapies in the large and rapidly growing osteoporosis market. To address the need for more convenient and patient friendly, non-injectable dosing of Ostabolin-C, the Company is collaborating with Nektar Therapeutics in the development of an inhaled dry powder formulation of Ostabolin-C, which is currently in Phase I clinical studies.

Zelos is led by a team of seasoned biopharmaceutical executives, and is based in West Conshohocken, Pennsylvania and Ottawa, Ontario. More information is available at www.zelostherapeutics.com.

Ostabolin-C is a trademark of Zelos Therapeutics, Inc.