He overhauls ImClone Systems. Pushes MedImmune into the arms of AstraZeneca. And forces Biogen into play. Now, Carl The Raider may be going after Genzyme. Icahn Capital Management reported it owned 1.5 million shares of Genzyme stock as of Sept. 30, or less than 1 percent of the biotech, in a filing with the Securities and Exchange Commission, The Boston Globe reports.

It’s too early to know exactly what Icahn has in mind for Genzyme, one of the world’s biggest biotech companies with a market value of close to $19 billion and more than 9,000 employees, the Globe notes. The company, led by industry veteran Henri Termeer, is known for producing powerful treatments for rare disorders, such as Gaucher’s disease and Pompe disease.

Icahn hasn’t publicly stated whether he plans to increase his stake in the company or push for any changes. And he didn’t return a call seeking comment last night, the Globe writes. Genzyme spokeswoman Caren Arnstein tells the paper the biotech is aware of Icahn’s investment, but generally doesn’t comment on actions by specific shareholders. “Genzyme’s management is focused on building value for all of our shareholders,” she says. Nonetheless, Icahn’s disclosure yesterday immediately sparked speculation that he could push Genzyme to sell.

Interestingly, the Globe points out that few people noticed when Icahn initially bought less than 1 percent of Biogen’s shares last summer. But Biogen shares soared after Icahn asked federal regulators for permission to take a larger stake in August. And last month, Biogen said it would look into selling the company after receiving several expressions of interest, including one from Icahn, earlier this year. Pfizer was among those that looked.

Genzyme’s shares have already been buoyed by speculation in recent months that it could be acquired. Shares have climbed 9 percent over the past 52 weeks, better than the S&P 500’s 6 percent gain during the same period. “There’s certainly a lot that someone might find attractive” about Genzyme, Brian Abrahams, an analyst at CIBC World Markets, tells Bloomberg News. “They have solid growth. There are certainly a lot of attractive qualities to a large pharma investor.”

Meanwhile, iIn yesterday’s SEC filing, Icahn also confirmed reports that he had increased his stake in Biogen, the Globe writes. As of the end of September, Icahn reported holding 8.8 million shares, or about 3 percent of the company, up from 2.7 million shares in a previous filing. Analysts say Biogen could sell for as much as $30 billion, which would give Icahn a hefty profit, but Biogen shares have waned in the last month on concern that drugmakers might find the biotech too pricey and might not bid after all.