The Amgen ceo sought to reassure investors at the Bear Stearns Healthcare Conference today the biotech can overcome a laundry list of problems with Medicare and the FDA concerning its anemia drugs, which may be widely restricted.

“We’re a company that obviously has more than our share of challenges right now,” Kevin Sharer told the Wall Street crowd, the Associated Press reports. “We have a new reality in the business and its not a completely predictable dynamic.” And he added Amgen plans to continue disputing the Medicare decision to restrict reimbursement on the Aranesp and Epogen drugs, which are used to treat chemo patients with anemia or kidney failure. An FDA panel meets tomorrow to discuss safety issues.

But defiant as ever, Sharer said Amgen “can hack it” and will be able to handle all of the problems with the federal government. Amgen is trying to muster support from physicians and patient advocates in its dispute over the Medicare decision. Thanks to an intense Amgen lobbying effort, the US Senate last week passed a resolution requesting the agency reconsider its reimbursement decision.

Sharer offered his own spin: He said the Senate move suggests there are public policy issues at stake beyond Amgen and that it was unusual to pass such a resolution so shortly after the legislators returned from the August break, the AP wrote.

Aranesp was Amgen’s biggest drug in 2006, with $4.12 billion in sales, the AP notes. But sales have slid since the FDA recommended stricter label warnings and asked for more studies following reports of potentially fatal side effects. Medicare then set new reimbursement rules, saying the drugs are only necessary for patients with hemoglobin levels of less than 10 grams per deciliter. The World Health Organization’s definition of anemic is a hemoglobin concentration of less than 13 deciliters.

Until recently, Sharer denied Amgen faced a crisis, but last month, he confessed and announced plans to slash up to 2,600 jobs and close facilities.

So far, private insurers are still basing coverage for the drug on the World Health Organization’s definition of anemic, Sharer told the crowd, but Amgen will have a better idea of the revenue situation for Aranesp in several months, the AP reports.

Amgen’s oncology drugs take in 40 percent of revenue from Medicare payers and 60 percent from private payers. The reimbursement decision could result in a two-tier system for anemia treatment, where physicians decide on treatment based on the level of a person’s insurance, Sharer said. “That’s a very distasteful way to practice medicine,” he said.

Amgen is also still embroiled in a patent dispute with Roche over the anemia treatments. “We’re going to get more clarity on all of this in the next few months,” Sharer said.