Zelos Therapeutics Presents Positive Data at ASBMR on Subcutaneous and Inhaled Delivery of Cyclic PTH (1-31) (Ostabolin-C(TM)).

-12-month Phase 2 trial with subcutaneous Ostabolin-C provides strong clinical validation in osteoporosis patients; Phase 1 trial data support feasibility of non-injectable delivery of PTH analogues-

WEST CONSHOHOCKEN, Pa. -- Today Zelos Therapeutics announced that it released data in two presentations at the 29th Annual Meeting of the American Society for Bone and Mineral Research (ASBMR) that represent strong proof of concept for cyclic PTH (1-31) (Ostabolin-C([TM])) as an osteoporosis therapeutic. The data were from a 12-month Phase 2 randomized, placebo-controlled, dose-ranging trial of subcutaneous Ostabolin-C in post-menopausal women with diagnosed osteoporosis, and a Phase 1 healthy volunteer study in post-menopausal women of an inhaled formulation of Ostabolin-C developed with Nektar Therapeutics. Ostabolin-C, a proprietary cyclic parathyroid hormone (PTH) analogue, is in late stage clinical development for the treatment of osteoporosis.

"Zelos has clearly demonstrated that Ostabolin-C produces highly significant increases in bone density, and that its clinical effects are established early and remain durable through 12 months of treatment," said Brian MacDonald, MB, ChB, PhD, Chief Executive Officer of Zelos. "Furthermore, the Phase 1 study represents the first time that an inhaled formulation of a PTH analogue has shown an increase in serum markers of bone formation in clinical use. We are very pleased that these studies have provided us with such a strong clinical rationale for continued development."

Phase 2 Study Results

The initial Phase 2 study evaluated the safety and efficacy of four months of treatment with subcutaneous injections of Ostabolin-C in 261 post-menopausal women aged 45-75 with low bone mass. Approximately one-third of the study population had a history of bone fracture. 198 study subjects then continued into an eight-month blinded extension study. Study subjects received one of four active doses of Ostabolin-C (7.5, 15, 30 or 45 microgram/day) or placebo. The data showed that the primary endpoint was achieved with a significant change in lumbar spine bone mineral density (LS-BMD) at one year. An increase in LS-BMD was observed in all treatment groups at one year with a maximum mean increase of 11%. The proportion of patients who developed a clinically relevant LS-BMD increase of 3% or more was 79% after 4 months and 97% after 12 months in the 45 microgram dose group. Significant increases in BMD of the hip were also observed. Adverse events were in line with what is typically expected from PTH analogues. Hypercalcemia was only observed with significantly higher incidence than placebo in the 45 microgram group. Most occurrences were mild.

The Phase 2 results were discussed by Anthony Hodsman, M.D., Professor of Medicine, University of Western Ontario, in a podium presentation at ASMBR on Tuesday, September 18 at 10:45 a.m. Hawaii Time.

"Without therapeutic intervention, a patient with osteoporosis who has fractured his or her hip, spine or wrist is at significant risk of another fracture," commented Dr. Hodsman. "With only one FDA-approved anabolic agent, there is a clear need for new therapies that can safely and effectively build new bone. This robust Phase 2 study clearly demonstrates that Ostabolin-C should be further investigated as a novel PTH analogue to reduce fracture risk in patients with osteoporosis."

Phase 1 Study Results

Zelos also presented Phase 1 data for an inhaled formulation of Ostabolin-C delivered with the Nektar T326 inhaler. The randomized, double-blind, placebo-controlled repeat escalating dose study evaluated the pharmacokinetic, safety, and efficacy profiles of inhaled Ostabolin-C in healthy post-menopausal women. Treatment duration was 28 days. The study demonstrated the ability of inhaled Ostabolin-C to increase serum markers of bone formation to levels comparable with the effect of subcutaneous delivery of Ostabolin-C at a similar time point. The safety profile of inhaled Ostabolin-C was consistent with the PTH analogue class and no serious adverse events were reported. There were no treatment-emergent pulmonary or cardiovascular adverse events and no effects on pulmonary function were identified.

The Phase 1 trial was exhibited in a Plenary Poster presentation on Sunday, September 16 and Monday, September 17.

About PTH in the Treatment of Osteoporosis

Osteoporosis is a major public health issue in the United States and worldwide, affecting more than a third of post-menopausal women but also a significant and increasing number of elderly men. It is a silent disease and many sufferers present to the physician for the first time when they experience a hip, spine or wrist fracture. Such patients have already lost a large amount of bone strength and are at very high risk of another fracture. The consequences of recurrent osteoporotic fractures are severe in terms of pain, disability, loss of independence and increased mortality. To effectively reduce fracture risk in such patients, therapies to create new bone and actively increase bone strength are required. PTH (1-34) is the only such bone building therapy currently approved in the U.S. and has been shown to reduce fracture rates in patients with severe osteoporosis by 65%. Despite this proven efficacy, the majority of patients with severe osteoporosis do not receive PTH therapy. Therefore, there is a significant opportunity for new approaches to PTH therapy to enter the market that can overcome the existing dosing, formulation and tolerability limitations.

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 and which may become a leading osteoporosis therapeutic. To address the need for more convenient and patient friendly, non-injectable dosing of Ostabolin-C, the Company is exploring alternative delivery methods including a collaboration with Nektar Therapeutics in the development of an inhaled dry powder formulation of Ostabolin-C. Zelos is also developing its PTH analogues in other indications, including the treatment of fracture in patients with osteoporosis.

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

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