Altus Pharmaceuticals Presents Results from ALTU-135 (TheraCLEC(TM)) Phase II Study in Cystic Fibrosis Patients with Pancreatic Insufficiency.

CAMBRIDGE, Mass. -- Study meets primary safety and efficacy endpoints Largest Prospective Study for Pancreatic Insufficiency in Cystic Fibrosis Patients

Altus(R) Pharmaceuticals Inc. presented results from its Phase II clinical trial of ALTU-135 (TheraCLEC(TM)) in cystic fibrosis (CF) patients with malabsorption due to pancreatic insufficiency at the North American Cystic Fibrosis Conference in Baltimore, MD. In the study, when delivered at a fixed dose, ALTU-135 was well-tolerated and achieved statistically significant improvements in the absorption of fat and protein as well as an overall improvement in the absorption of carbohydrates, all of which are essential for proper nutrition and growth. The Phase II study enrolled 125 patients who were treated at 26 CF centers in the U.S., and the Company believes that it represents the largest prospective, randomized, double blind, and dose-ranging trial conducted to evaluate the safety and efficacy of enzyme replacement therapy in the treatment of CF patients with pancreatic insufficiency.

The results of this Phase II study showed improvements in fat (p less than 0.001) and protein absorption (p less than 0.001) as well as improvements in carbohydrate absorption. Importantly, the largest improvement in fat and protein absorption in patients receiving ALTU-135 was demonstrated in patients who had the lowest level of fat and protein absorption during a baseline period when they were not taking any enzymes. The Company believes this is the first study to demonstrate that lipase, protease, and amylase, the three active ingredients in ALTU-135, are important in the treatment of pancreatic insufficiency. Altus also believes this is the only trial of its kind to concurrently evaluate the impact of a fixed dose of an enzyme replacement therapy on the absorption of fats, proteins and carbohydrates and incorporate an innovative trial design which included the use of several novel endpoints. ALTU-135 was well tolerated overall, with reported adverse events following expected patterns for CF patients, and consistent with results from previous ALTU-135 studies.

"We are encouraged by these Phase II results. As the Food and Drug Administration noted in April 2004, there is a need for efficacious pancreatic enzyme replacement therapies with consistent quality, potency, and stability. We are optimistic that ALTU-135 will meet these goals while providing a more convenient option for patients," said Alan Kimura, M.D., Ph.D., Vice President, Clinical Development and Medical Affairs, Altus Pharmaceuticals. "We have begun working with the FDA to finalize our Phase III clinical trial protocol in order to begin recruiting clinical sites as quickly as possible. The Company is also grateful to our investigators and study participants for their support of this important and innovative study."

About ALTU-135

ALTU-135 is an orally-delivered, microbially-derived enzyme replacement therapy in development that utilizes the Company's protein crystallization and cross-linking technology for the treatment of malabsorption due to exocrine pancreatic insufficiency. ALTU-135 consists of three enzymes, lipase, protease and amylase that are delivered in a consistent ratio and is designed to improve fat, protein, and carbohydrate absorption in pancreatic insufficient individuals. ALTU-135 is designed to be highly concentrated, stable and pure and to allow patients to take a single capsule per meal or snack, whereas current products are derived from pig pancreases and require a significantly higher pill burden. This reduced pill burden for ALTU-135 is expected to provide greater convenience for the patient and result in improved compliance and therefore effectiveness. ALTU-135 has been granted Orphan Drug designation in the United States and Europe. ALTU-135 was also granted fast track designation by the U.S. Food and Drug Administration (FDA) in November 2003, and was accepted into the FDA's Continuous Marketing Application Pilot 2 Program in February 2004.

About Pancreatic Insufficiency

Pancreatic insufficiency is a deficiency of the digestive enzymes normally produced by the pancreas and can result from a number of disease conditions including cystic fibrosis, chronic pancreatitis and pancreatic cancer. Pancreatic insufficiency can lead to malnutrition, impaired growth, poor survival and decreased quality of life. ALTU-135 is intended to replace the functionality of the missing digestive enzymes to promote and maintain proper digestion and growth in affected patients.

About Cystic Fibrosis

CF is a genetic disease affecting approximately 30,000 people in the United States. A defective gene causes the body to produce abnormally thick, sticky mucus that results in severe lung infections and causes pancreatic insufficiency, which impairs digestion. Approximately 90% of cystic fibrosis patients suffer from pancreatic insufficiency.

About Altus Pharmaceuticals Inc.

Altus Pharmaceuticals is focused on developing and commercializing protein therapeutics for patients with chronic gastrointestinal and metabolic diseases. Altus' in-depth knowledge of protein crystallization has resulted in a proprietary pipeline of orally delivered and injectable protein replacement products. As a company, Altus is committed to improving the quality of life of patients. More information about Altus and its clinical development programs can be found at www.altus.com.