While the Super Bowl isn't played until Sunday, the past week had several health-care stock champions. Here are three of the most humongous winners of the week.

Kick off with Keryx
Keryx Biopharmaceuticals (NASDAQ:KERX) scored big-time this week with its announcement of phase 3 results for kidney disease drug Zerenex. Shares soared nearly 100% before ending the week up more than 42%. 

The phase 3 study found that Zerenex helps lower phosphate levels in patients with end-stage renal disease, or ESRD. Because high phosphate levels can lead to serious health problems, these results were very encouraging. Additionally, the study showed that Zerenex reduced the need for ESRD patients to receive intravenous treatments to address iron deficiencies. 

Keryx's other big news of the week was a secondary share offering of $55 million. Actually, this news ties into the good news for Zerenex. The company moved ahead with the offering to raise cash for commercialization plans for the drug.

Get a little help from the rock
Shares of Sunesis Pharmaceuticals (NASDAQ:SNSS) jumped nearly 27% this week. Why? You won't find a clinical study result announcement, earnings release, or analyst upgrade that served as a catalyst. Nonetheless, there was some great news for Sunesis this week.

Huge investment firm Blackrock filed form SC 13G with the Securities and Exchange Commission on Wednesday. An SC 13G is required anytime an entity's ownership of a publicly traded company reaches 5%. What this means is that Blackrock has bought -- and perhaps is continuing to buy -- a much larger stake in Sunesis. As of last September, Blackrock owned less than 2% of the biotech. 

The attraction to Sunesis no doubt stems from the company's promising cancer drug vosaroxin. The drug is currently in two phase 3 trials targeting treatment of acute myeloid leukemia, or AML. Sunesis thinks vosaroxin could reach annual sales of $1 billion if it gains regulatory approval in the U.S. and Europe.

My hunch is that Blackrock views Sunesis as a prime acquisition target for a larger company in the not-too-distant future. Celgene (NASDAQ:CELG) could make a good fit. The booming biotech has a sales force in place for Vidaza but no longer has patent protection for the drug in the U.S.  

No need for alignment
Shares of Align Technologies (NASDAQ:ALGN) climbed more than 11% this week. The company reported solid earnings results on Wednesday.

Sales for its Invisalign dental alignment product were up nearly 10% in the fourth quarter, driving overall revenue up. Align's adjusted earnings of $0.27 per share easily beat analyst expectations of $0.22 per share.

The positive results yielded more good news for Align as well. Jefferies announced a buy rating for the stock with a $36 price target. That amount happens to exactly match the median price target for Align and represents a potential 13% upside.

Super champion
Which of this week's winners has the best chance to score the most in 2013? It just might be Sunesis. The company should announce interim safety results from its phase 3 VALOR trial of vosaroxin in June. If those results are positive, Sunesis could be a champion stock this year. As for that other competition being played on Sunday, I'll pick San Francisco by seven points.