Robert Duggan

Robert Duggan
$1.2 billion

Robert Duggan is the newest billionaire on our list. The Pharmacyclics CEO and life sciences veteran busted past the $1 billion mark after the value of his company's ($PCYC) shares tripled over the past year in the wake of progress with its experimental drug ibrutinib against chronic lymphocytic leukemia (CLL).

Duggan, who had megamillions from previous holdings prior to reaching billionaire status, was worth about $1.2 billion on paper as of last month, according to Forbes. The lion's share of his wealth hinges on the value of his 20% stake in his Sunnyvale, CA-based biotech, which was worth about $5.6 billion as of March 29.

He amassed the large interest in Pharmcyclics mostly from his personal investments in the company from 2004 to 2011 at a cost of $42 million, according to Bloomberg. He wrested control of the board in 2008, reaching into his own pocket to lend the company $6.4 million between December of that year and March 2009. Wisely, he took stock as repayment for the loans. Yet since he became chairman in September 2008, Duggan hasn't cost the company or its shareholders a dime, going sans salary or other compensation from Pharmacyclics.

The fate of his billionaire status rests with one drug. Ibrutinib, a compound designed to block Bruton's tyrosine kinase, has shown an ability to kick some cancer ass without severe side effects--an important feature of the therapy because 70% of the 15,000 or so patients diagnosed with CLL in the U.S. every year are elderly. In December the company reported that 71% of previously untreated patients and 67% of those with relapsed disease responded completely or partially to the therapy.

Based on earlier data, Johnson & Johnson ($JNJ) stepped up with a $975 million partnership pact with Pharmacyclics for a share of the potential spoils from ibrutinib sales, which analysts cited by Bloomberg have estimated could hit $5 billion. What is more, the FDA awarded the compound "Breakthrough" status earlier this year, meaning the treatment could gain a rapid approval without completing all three phases of development usually required to garner a market green light.

Like many of his fellow biotech billionaires, Duggan has worked in his industry for decades. He previously helmed the surgical robotics company Computer Motion until 2003, when the company merged with rival Intuitive Surgical. Bloomberg estimated that his non-Pharmacyclics fortune stands at about $250 million, so he won't be in the poorhouse if ibrutinib tanks.

For more:
J&J, Pharmacyclics score 'breakthrough' coup with blockbuster hopeful ibrutinib
Pharmacyclics' success with ibrutinib spawns a rare biotech billionaire

Robert Duggan