The FDA's Pulmonary Allergy Drugs Advisory Committee ismeeting today to decide the fate of Genentech Inc.'s product fortreating cystic fibrosis. If the committee recommends approvalof Pulmozyme (DNase), it will be the fastest time on recordfrom regulatory filing to positive review for a new drug.
Genentech filed the product license application (PLA) forPulmozyme on March 30. Only Taxol (for treating advancedovarian cancer) at five months and AZT (for treating AIDS) atabout six months have come close to such abbreviated timeframes. Even Chiron Corp.'s Betaseron for treating relapsingremitting multiple sclerosis, which gained final FDA approvalon July 23, took nine months to come before committee.
Genentech (NYSE:GNE) of South San Francisco, Calif., completedits Phase III clinical trials on Pulmozyme in December 1992and reported those results in January at the IntermountainThoracic Society Meeting and in March at the American LungAssociation Meeting.
The 968-patient trial demonstrated that the recombinanthuman enzyme DNase reduces the rate of respiratory infection(as measured by the need for intravenous antibiotics) andsignificantly improves lung function in cystic fibrosis (CF)patients, with no adverse side effects.
DNase works by breaking up the thick secretions (full of theDNA spilled from infection-fighting white blood cells) thataccumulate in the lungs of patients with CF. Those secretionscause impaired breathing, persistent lung infection andprogressive degeneration of lung function. This chronic damageto the lungs manifests itself as a gradual loss in breathingcapacity and chronic lung infections with periodichospitalizations.
These all lead to an early death for CF patients, who live for anaverage of 29 years with this most common (amongCaucasians) of fatal genetic diseases. It affects one in 2,500 livewhite births. In the U.S., there are about 30,000 individualsafflicted with CF, although there are close to 10 million carriers.
The clinical trial results indicated that "use of Pulmozyme oncea day (2.5 milligrams) resulted in a 31 percent reduction in theuse of parenteral antibiotics for all respiratory infections."Moreover, "CF patients' lung function, as measured by forcedexpiratory volume, improved 5.8 percent when PulmozymeDNase was used once a day ... and was maintained throughoutthe period of the study."
Most biotechnology analysts who follow Genentech have longpredicted that Pulmozyme will be on the market by the end ofthis year. Even without having a concrete idea of the drug'sfinal pricing, the analysts see markets of anywhere from $250million to more than $1 billion for the drug, which couldeventually be used to treat chronic bronchitis as well as cysticfibrosis.
Joseph Edelman, an analyst with Prudential Securities Inc.,called his Pulmozyme sales estimates of $270 millionworldwide in 1996 "conservative." Edelman sees a potentialmarket of more than $1 billion for the drug if its approvedfrom treating chronic bronchitis.
Cowen & Co. analysts David Stone and Carol Werther foresee apotential market of anywhere from $500 million to $1 billion.And Oppenheimer & Co.'s David Ebersman, who hasn'tcompleted up his projections yet, told BioWorld thatPulmozyme could be a $200 million drug -- just for treating CF-- in the U.S. and Canada.
Genentech's stock closed at $43.88 a share on Friday, up 13cents.
-- Jennifer Van Brunt Senior Editor
(c) 1997 American Health Consultants. All rights reserved.