A pair of articles in Thursday's New England Journal of Medicine confirm that rival biotechnology drugs from Genentech Inc. and Amgen Inc. are effective treatments for many psoriasis patients.
An editorial in the journal signed by dermatologist Dr. Robert C. Kupper of Boston's Brigham and Women's Hospital called the drugs "a boon to patients" but cautioned "there are insufficient data to support claims that one of these agents is superior to the other."
Amgen, Genentech and other biotechnology companies are hungrily eyeing the psoriasis market, the next big drug category. Sales of biotech drugs for the chronic skin disorder could reach $1 billion by 2006, according to some stock analysts. The companies estimate that 500,000 to 1 million patients in the U.S. have moderate to serious cases.
Last month Genentech's drug Raptiva was approved by the Food and Drug Administration for psoriasis.
Amgen's drug Enbrel should reach $1.2 billion in sales this year largely to treat rheumatoid arthritis patients. Analysts estimate that 10% of Enbrel's sales are from off-label uses for psoriasis; the FDA is expected to approve Amgen's drug to treat the skin disease by March.
Much of the data reported in the journal articles were disclosed months ago at medical meetings. The journal, however, reaches a wider audience and carries a level of prestige important to scientists and drug makers. The articles are particularly useful to Thousand Oaks-based Amgen because it does not yet have FDA permission to market Enbrel for psoriasis. Amgen's sales force can't distribute reprints of the article but can refer dermatologists to the journal.
Based on research in Thursday's journal, Enbrel appeared to work better than Raptiva, but the studies weren't directly comparable. No more than 50% of patients showed significant improvement after 12 weeks on either drug. The studies were paid for by the drug companies.
Both drugs are expensive, and patients could face problems getting reimbursements from insurance companies. The most effective dose of Enbrel identified in the Amgen study would cost $26,000 annually compared with $14,000 a year for the approved dose of Raptiva.
Some patients on Raptiva had transient flu-like symptoms at the start of treatment. Patients on Enbrel had no more side effects than patients on a placebo -- a surprise, said co-author Dr. Craig Leonardi of Saint Louis University Medical School, because rheumatoid arthritis patients have a higher rate of infection on Enbrel.
The study has continued for a year and side effects in psoriasis patients have remained low, said Amgen spokeswoman Andrea Rothschild.
Amgen gained $1.26 to $60.10 on Nasdaq, while South San Francisco-based Genentech rose 66 cents to $83.90 on the New York Stock Exchange.