NEWS OF THE WEEK BIOCHEMISTRY
ASTHMA NEXUS
chitinase functions best at p H 2.3. Elias' group suspects that current steroid therapy works partly because it raises the p H of the
Researchers pinpoint human chitinase as new target for asthma therapy
E
VER SINCE HUMAN C H I T I N -
ase was discovered in the 1990s, its presence has been somewhat of an enigma. Chitinase breaks down chitin—the stuff of insect exoskeletons and parasite cell walls, ^ t mammals themselves make no chitin. Now, researchers at Yale University and McGill University, in Quebec, have discovered that one human chitinase (acidic mammalian chitinase) is a key player in the acute inflammation pathway of asthma [Science, 304,1678 (2004)}. The group, led byjack A. Elias at Yale, first recognized a strong similarity between the classic antiparasitic response of prokaryotes and simple eukaryotes and the exaggerated inflammation re-
action in humans (called the Th2 response) that leads to asthma. Because chitinase breaks down chitin in parasite cell walls, it is highly involved in the antiparasitic reaction, "so we thought chitinase might also be upregulated in human asthma," says Qutayba Hamid, a specialist in asthma at McGill. The group induced a Th2 response in mice and, indeed, saw levels of acidic mammalian chitinase rise. They also compared lung tissues of human asthma sufferers with normal patients. Only asthma patients had high levels of chitinase in their epithelial and macrophage cells. Further, one of the symptoms of acute asthma is airway acidification, and acidic mammalian
PHARMACEUTICALS
NOVARTIS TO ACQUIRE SABEX HOLDINGS The $565 million purchase will enlarge Swiss firm's stake in generic drugs
N
OVARTIS HAS SIGNED A DE-
finitive agreement to acquire privately held Sabex Holdings, a 23-year-old Canadian maker of generic pharmaceuticals, for $565 million. The acquisition of Sabex, based in Boucherville, Quebec, will add $90 million in sales to Novartis' generic drug unit, Sandoz, which had sales of $2.9 billion in 2003. Sabex offers a range of copycat drugs produced at FDA-approved facilities that include injectables, suppositories, ophthalmic medicines, and other products coverHTTP://WWW.CEN-ONLINE.ORG
ing more than 80 molecules. It received approval to sell eight new products over the past year and has 50 more under development. Unlike other ethical drugmakers, Novartis has aggressively pursued growth in generic drug markets. In 2002, Novartis bought the Slovenian generic drugmaker Lek for nearly $900 million. At the time, Lek had almost $400 million in sales. The Sabex purchase will make Sandoz the leading injectable generics manufacturer in Canada and the sixth-largest Canadian generics maker.
airways. More generally, they say any drug that hampers the activity of acidic mammalian chitinase will likely lead to milder inflammation in asthma sufferers. The fact that some asthma attacks are triggered by exposure to house dust mites (and thus their chitin) may also be related to chitinase activity, Hamid says. But experiments haven't looked atthatyet.-LOUISADALTON
Sandoz CEO Christian Seiwald explains that the firm paid a premium for Sabex because it "provides Sandoz with a leadership position in injectable generics in Canada and a platform to build a generic injectables business globally, particularly in the rapidly growing U.S. market." The U.S. market for injectable medicines losing patent protection is set to double from $7 billion to $14billionbetween2002 and 2010, Sandoz says. Sabex has expanded sales to US. customers and increased manufacturing capacity since 2002, when private equity firm RoundTable Healthcare Partners purchased a majority interest in the company But Sabex's value is not just as a channel into the U.S. injectables market. Sandoz says it expects the Sabex sales force to help increase sales of its existing portfolio of solid-dosage drugs in Canada.— MARCRE1SCH C&EN / JUNE U ,
2004
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