Dr. Steven Shak, Director of Pulmonary Research at Genentech, presented an overview of DNase research. DNase is a bioengineered copy of the human enzyme. When people with CF inhale an aerosol of DNase, their mucus becomes less viscous and easier to clear from the airways.
The latest clinical trials of 968 patients reveal an average of 6% increase in lung function with DNase. Also, proper use reduces incidence of infection even in cases when it does not increase baseline FEV (forced expiratory volume) scores, a measure of lung function. Most people tolerate it well and note only minimal adverse effects. In this study, some patients had voice alteration and laryngitis but most cases cleared within 21 days. The drug has benefited males and females age five and over, who had all levels of predicted FEV above 40%. Optimal results came from using DNase every day, as a dose lasts about one day in the lungs.
Dr. Shak, the inventor of DNase, shared an insight into how research builds on what others have done before. "In 1989, I was researching CF mucus," he said. "I found an article from Pediatrics written 30 years ago about the composition of mucus in CF patients. It showed that there were large amounts of DNA present in the sputum of CF patients. The author of the article was Dr. Barbero who is also speaking to us today!"
DNase is produced by Genentech under the name Pulmozyme. It costs about $28 a day which is very close to the cost of manufacturing the drug. "Genentech wants to make Pulmozyme available to everyone who needs it," Dr. Shak told the group. Genentech has created an endowment to help uninsured people, or people who have trouble with insurance co-payments. The endowment's toll-free phone number is 1-800-297-5557.
During the questions that followed, Dr. Shak fielded several questions about use of DNase in a wider population, specifically children younger than five, people with normal lung function but other CF symptoms, and people with sinus disease. "Scientifically, beginning it [treatment with DNase] early makes sense," he said, predicting that upcoming studies would show the efficacy of DNase. His views were seconded by Dr. Robert Bocian who treats patients at Lucile Salter Packard Children's Hospital at Stanford.
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