With the tremendous success of Genentech (NYSE:DNA) this year, Amgen (NASDAQ:AMGN) must have felt left out of the party. In fact, Genentech's market cap exceeded Amgen's.

Well, yesterday, Amgen recovered some of its luster. The company reported its second-quarter earnings, and they were certainly in the "blowout" category. Net income was a cool $1 billion, or $0.82 per share, which was a 38% increase from the same period a year ago. During this time, revenues increased 23% to $3.2 billion.

In fact, Amgen would have made $1.1 billion. Basically, it had to take a charge for expenses for the acquisition of Immunex.

But the acquisition was money well spent. For example, Immunex's drug Enbrel posted a 45% increase in sales to $639 million.

There was also tremendous strength from Amgen's Aranesp, which treats anemia in cancer patients. Sales increased 36% to $837 million. Actually, Amgen is making inroads into the market share of Johnson & Johnson (NYSE:JNJ), which has a competing product to Aranesp.

There was a cloud of uncertainty for Amgen this year -- in light of the changes in Medicare rules. But according to the earnings conference call, there has been minimal impact for Amgen. That spells good news for Aranesp, which relies heavily on Medicare reimbursement. The company has been able to work on strategies to manage through the new regulations, according to the conference call. As a result, expect the growth to continue in Aranesp.

At least in the short run, Amgen's momentum should continue. The company provided 2005 guidance of profits between $3.10 and $3.20 per share. This compares with previous guidance of $2.80 to $2.90 per share.

Interestingly enough, since March, biotech stocks have been strong. And the bullish results from Amgen should fuel the rally. After all, Amgen's stock surged an incredible 15% on the earnings news. A move like that is a good indication that more money will come into the sector -- and fast.

Still, biotech is always dicey. If a company fails in its trials with the FDA, it doesn't matter whether investors are bullish with the sector. But based on the good news on Medicare and strength across various several major drugs, Amgen's likely poised to continue growing profits throughout the rest of the year.

Fool contributor Tom Taulli does not own shares of companies mentioned in this article.