Last week, before Myogen ( MYOG) dropped a partnership bombshell on the market, a well-placed insider sold the last of his shares in the company. John Julian, Myogen's senior vice president of commercial development, walked away from his latest transaction with more than $1 million -- or four times his annual salary. He is among several Myogen insiders, including the CEO and CFO, who began shedding stock under prearranged plans after the shares started rallying last summer. Myogen suddenly announced Julian's retirement on Monday. Julian follows the company's founder out the door . Julian, hired in mid-2000 to help bring Myogen's new drugs to the market, executed his final stock sale five days before the company revealed an unpopular agreement with GlaxoSmithKline ( GSK). Under the terms of that deal, Myogen has accepted an upfront payment of just $20 million -- with a mere shot at getting more -- in exchange for certain rights to a drug that, some assumed, would generate nearly $400 million in sales down the road. "This is a company that, not too long ago, had three major drugs in the pipeline," notes Robert Lawton, a vice president at Westport, Conn.-based Source Capital who is short the stock. "But two of those three drugs are now essentially out of their hands. So now everybody is betting the farm on the last one." In other words, Myogen -- like so many in the biotechnology space -- now looks like a possible one-hit wonder at best. Lawton established a short position in Myogen's highflying stock "at $39 and change" before the company's disappointing announcement. The stock went on to hit a record high of $42.27 on Monday morning before plunging 15% to $35.12 the following day on news of the GlaxoSmithKline deal. But Lawton has ticked off a number of reasons -- ranging from the company's poor track record and rich corporate perks to risks associated with the one drug it has left -- for keeping his bearish view intact.