Bristol-Myers Squibb Co.'s purchase of Amira Pharmaceuticals Inc. for $325 million upfront and another $150 million in downstream milestones shows that prior licensing deals and multiple programs in a pipeline don't necessarily curb a start-up's acquisition potential, provided investors are thinking smartly about deal structures that create separate value streams for the various products in the portfolio.

In five short years, Celgene has used the cash from the blockbuster success of its flagship product Revlimid to pursue a wide range of deals for revenues now and new markets later. Its homegrown R&D has created a bountiful late-stage pipeline. It’s projecting even more Revlimid success in the next few years. So why aren’t investors buying?

The April 15 deal between Agios Pharmaceuticals Inc., a start-up barely two years old working in a novel area of cancer research, and Celgene Corp. is noteworthy for a number of reasons, among them its sheer size: the $130 million up-front payment associated with the deal is the largest year-to-date for a pharmaceutical alliance for which metrics have been disclosed, and is particularly hefty for a start-up that has yet to put a molecule in the clinic.