Just three months ago, Amgen was still considered one of the biggest success stories of the fast-growing biotechnology industry. Now some analysts are comparing it to a lumbering, stumbling pharmaceutical giant that leans too heavily on an aging product portfolio. A series of setbacks, some unexpected and some perhaps self-inflicted, pose the greatest challenge in the company’s heretofore charmed 27-year history. And some crucial events in coming weeks could make clearer whether the company has simply hit a stretch of “choppy water” – as its chief executive contends – or whether, as some analysts say, the company’s best days may be behind it. “The barrage of bad news that’s come out on Amgen in the past 60 days is absolutely unprecedented in the biotech sector,” said Mark Schoenebaum, a biotechnology stock analyst at Bear Stearns. Amgen’s shares are down nearly 20 percent since late January, knocking about $20 billion off the company’s market value. But the stock has edged up a bit since its recent low of $55.13 on March 29, as some investors have apparently adopted management’s view that it is too soon for a fire sale. “We are not in a crisis, that’s for sure,” Kevin W. Sharer, Amgen’s chairman and chief executive, said in an interview. In a crisis, “people don’t know what to do,” he said. “People’s hair is on fire. Confidence is challenged. We’re not there.” Rather, he said, “we’re in some pretty choppy water.” The biggest waves are several recent studies suggesting that the company’s blockbuster anemia drugs, Aranesp and Epogen, might be harming patients, particularly if overused. Those products accounted for $6.6 billion of Amgen’s $14.3 billion in revenue last year. The Food and Drug Administration put new warnings on the drugs last month, citing studies suggesting that Aranesp and Epogen might cause heart problems or hasten the death of cancer patients. On Wednesday, the company said it would briefly delay the reporting of its first-quarter results, originally scheduled for next week, to allow it to include data from a clinical trial of Aranesp. The financial results are now expected April 23. Late Tuesday, Amgen said that its chief financial officer, Richard D. Nanula, was resigning to “pursue other opportunities,” but would stay on for three months to effect a transition. It also said that Robert Bradway would succeed him as the finance chief. Adding to its woes, Amgen recently reported that patients in a clinical trial combining its new colon cancer drug, Vectibix, with other treatments were more likely to die than patients who got only the other treatments. As a result, Vectibix is likely to remain only a niche drug for now. Sizing up Amgen’s situation in a report titled “Looking More Like Large Pharma,” a Citigroup analyst, Yaron Werber, has predicted that Amgen’s revenues will grow only 4 percent a year through 2010. That would be well below its 20 percent annual sales growth from 2003 to 2006. The company has mainly reacted to the mounting uncertainty about future sales by taking cost-control steps like a hiring slowdown and postponing the opening of a new factory in Ireland. If sales drop further, Amgen says, more cuts can be made. Results due in May Just how painful should become clearer in the next few weeks. By early May, the company is expected to release the results of a crucial study testing Aranesp’s effect on the longevity of patients with small-cell lung cancer. Aranesp is approved to treat the anemia caused by cancer chemotherapy. If the May results indicate that patients taking Aranesp are more likely to die sooner than they might otherwise, “the tide will turn” against the drugs, said Dr. John A. Glaspy, a professor of medicine at UCLA. “We will not be able to justify treating lots of patients” with Aranesp, said Glaspy, who has received consulting and research fees from Amgen. An FDA advisory committee plans to meet May 10 to discuss the safety of the anemia drugs. And later that month another big drugmaker, Roche, might win FDA approval for an anemia drug that would compete with Amgen’s products. Epogen and Aranesp are both genetically engineered versions of erythropoietin, or EPO, a protein made in the kidneys to stimulate production of oxygen-carrying red blood cells. Johnson & Johnson sells a version of Epogen, marketed as Procrit, under a license from Amgen. The drugs have been shown to reduce the need for blood transfusions in patients with kidney disease and in cancer patients getting chemotherapy. But in November, a study found that patients with kidney failure who were treated aggressively with an EPO drug had more deaths and heart problems than patients who took only enough of the drugs to raise their levels of red blood cells by more modest amounts. Then a number of studies came out suggesting that use of Aranesp by cancer patients could worsen their disease or hasten their deaths. Amgen did not immediately disclose the results of one of the trials, done by Danish researchers, prompting an inquiry by the Securities and Exchange Commission. Amgen executives, and some outside scientists, say it is still far from clear if the drugs are truly dangerous. Most of the studies showing risks have problems in their methodology or have not yet been published. The risks also seem to be mainly in patients whose red-cell counts are raised beyond the level recommended by the drugs’ labels. New products key Whatever happens with sales of its anemia drugs, if Amgen is to remain a fast-growing company it must develop new products. But it has yet to show a particular skill in that area, even though it does have many test drugs in its pipeline. To this day, Amgen still largely lives off Epogen, first approved in 1989, and Neupogen, a drug approved in 1991 that prevents infections in patients receiving chemotherapy. Its biggest new products since then, Aranesp and Neulasta, were modifications of the original two. And its other big product, the rheumatoid arthritis drug Enbrel, was not homegrown but came as part of the company’s $10 billion acquisition of Immunex in 2002. After being promoted to chief executive in 2000, Sharer recruited Roger M. Perlmutter from Merck to run research and development. The research effort has roughly tripled since 2002, to more than 6,000 people and $3.4 billion in spending, and the number of drug candidates under development has similarly soared. Denosumab, a drug for osteoporosis and bone cancer, could be a blockbuster, and some investors say that it is now more important than ever to Amgen’s future. But it will be two or three years before it is known whether the drug is safe and effective enough to win approval.160Want local news?Sign up for the Localist and stay informed Something went wrong. Please try again.subscribeCongratulations! You’re all set!