PTC Therapeutics, Inc. Announces Data Supporting Cough Frequency as a New Outcome Measure in Evaluating Treatments for Cystic Fibrosis

SOUTH PLAINFIELD, N.J., May 21 /PRNewswire/ -- PTC Therapeutics, Inc. (PTC) today announced new data suggesting that the quantification of cough frequency may offer a clinically meaningful outcome measure in cystic fibrosis (CF). Cough is one of the most prominent and burdensome disease-related symptoms in CF. According to data presented today at the 2008 International Conference of the American Thoracic Society, patients with CF cough a remarkable 324 to 1,569 times per day, with an average of 643 coughs per day. In comparison, healthy individuals generally cough fewer than 16 times in an entire day, according to the European Respiratory Journal (Hsu 1994).

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"Cough is one of the major symptomatic manifestations of the underlying disease process in CF," stated Eitan Kerem, M.D., head of the Department of Pediatrics and Cystic Fibrosis Center, Hadassah University Hospital. "Chronic excessive coughing is a burden on CF patients and a source of anxiety for caregivers and loved ones. Frequent and intense coughing has a profound effect on the overall quality of life of the patient -- compromising work, school, sleep and social interactions."

CF is among the most common life-threatening genetic disorders worldwide and affects nearly 70,000 adults and children. Patients with CF lack the cystic fibrosis transmembrane conductance regulator (CFTR) protein, a chloride ion channel that maintains proper hydration of epithelial cells in the lungs, pancreas, and liver. Loss of the CFTR protein leads to chronic airway inflammation in association with obstruction and mucopurulent secretions, all of which provoke persistent coughing. While there are approved palliative treatments for CF, clinical development efforts would benefit from reliable quantitative endpoints that are clinically meaningful because they directly measure changes in how a patient feels and functions.

"The ability to quantify cough represents a significant step forward in our understanding of one of the most prominent symptoms of CF," added Preston Campbell, III, M.D., Executive Vice President of Medical Affairs at the Cystic Fibrosis Foundation. "A significant reduction in cough frequency would be of real value to patients."

The study was designed to assess cough frequency as a measure of clinical benefit. Quantitative measurement was achieved using a new technology, the VivoMetrics(R) LifeShirt(R), which integrates cough signals from chest wall motion transducers and a throat microphone and stores the data for computer analysis. FEV1 (Forced Expiratory Volume in the first second) and FVC (forced vital capacity) -- key measures of lung function -- were assessed by spirometry, and patients completed a symptom survey.

Patients included 19 adults not in CF exacerbation. Although there was occasional neck pressure due to the throat microphone, compliance was excellent, with cough data collected for a median of 24 hours. Cough frequency averaged 643 coughs per day (ranging from 324 to 1,569 coughs per day) and tended to increase with lower FEV1 and greater age.

"Anecdotal information concerning cough frequency in CF patients led us to assess cough quantitatively using the LifeShirt(R)," said Langdon Miller, M.D., Chief Medical Officer of PTC. "The cough frequency data announced today highlights the potential for cough assessment as an outcome measure that may be used in the development of new therapies for CF. We look forward to presenting data on the effect of PTC124 on cough frequency at the 31st annual European Cystic Fibrosis Society Conference in June, and to initiating longer-term trials later this year to further evaluate the clinical efficacy of PTC124 in patients with CF."

About Cystic Fibrosis

Cystic fibrosis (CF) is among the most common life-threatening genetic disorders worldwide. According to the Cystic Fibrosis Foundation, CF affects approximately 30,000 adults and children in the United States and, according to the European Cystic Fibrosis Foundation, it affects a similar number of patients in Europe. CF occurs in approximately one of every 3,500 live births, with approximately 1,000 new cases diagnosed each year in the United States. There is a commercially available genetic test to determine if a patient's CF is caused by a nonsense mutation, and it is estimated that nonsense mutations are the cause of CF in approximately 10% of patients in the United States. There is currently no available therapy to correct defective CFTR production and function. Instead, available treatments for CF are designed to alleviate the symptoms of the disease. These treatments include chest physical therapy to clear the thick mucus from the lungs, antibiotics to treat lung infections and a mucus-thinning drug designed to reduce the number of lung infections and improve lung function. In addition, the majority of cystic fibrosis patients take pancreatic enzyme supplements to assist with food absorption in digestion. There is a significant unmet medical need for treatments for the underlying cause of CF. More information regarding CF is available through the Cystic Fibrosis Foundation (www.cff.org).

About PTC124

PTC124 is an orally delivered investigational new drug in Phase 2 clinical development for the treatment of genetic disorders due to nonsense mutations. Nonsense mutations are single-point alterations in the genetic code that prematurely stop the translation process, producing a shortened, non- functional protein. PTC124 has restored production of full-length, functional proteins in preclinical genetic disease models harboring nonsense mutations. In Phase 1 clinical trials, PTC124 was generally well tolerated, achieved target plasma concentrations that have been associated with activity in preclinical models and did not induce ribosomal read through of normal stop codons. PTC124 has demonstrated pharmacodynamic proof of concept in Phase 2a clinical trials in nonsense-mutation-mediated Duchenne muscular dystrophy (DMD) and cystic fibrosis (CF).

About PTC Therapeutics Inc.

PTC is a biopharmaceutical company focused on the discovery, development and commercialization of orally administered, proprietary, small-molecule drugs that target post-transcriptional control processes. Post-transcriptional control processes regulate the rate and timing of protein production and are of central importance to proper cellular function. PTC's internally-discovered pipeline addresses multiple therapeutic areas, including genetic disorders, oncology and infectious diseases. In addition, PTC has developed proprietary technologies and extensive knowledge of post-transcriptional control processes that it applies in its drug discovery and development activities, including the Gene Expression Modulation by Small-molecules (GEMS) technology platform, which has been the basis for collaborations with leading pharmaceutical and biotechnology companies such as Pfizer, Celgene, CV Therapeutics and Schering-Plough. For more information, visit the company's website, www.ptcbio.com.

CONTACT: Jane Baj, PTC Therapeutics, Inc., +1-908-912-9167,
jbaj@ptcbio.com; Sheryl Seapy, Pure Communications, +1-949-608-0841,
sheryl@purecommunicationsinc.com, for PTC Therapeutics, Inc.

Web site: http://www.ptcbio.com/

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