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Clinical-stage biotechs Agenus Inc. (NASDAQ:AGEN) and bluebird bio (NASDAQ:BLUE)are developing new and exciting treatment options for cancer and other diseases. Both of their stocks also lost a great deal of their value over the past year. Agenus shares are about 53% lower than they were a year ago, and Bluebird has given up about 77% over the same period.

Both stocks look like potential bargains, so now is a good time to take a closer look at what's coming through their respective pipelines. Let's compare them on a handful of criteria to see which is the better buy.

Partnerships

One of the first things to check for when considering biotech stocks is interest from larger companies. You can tick this box for both of these biotechs, but the relevance of their partnerships to their overall operations is much different.

Agenus' candidate closest to approval is its QS-21 Stimulon adjuvant, basically a booster for vaccines under development by GlaxoSmithKline. Phase 3 successes for partnered malaria and shingles vaccines were a good sign, and Agenus expects Glaxo to file applications for approval of the shingles vaccine in the second half of the year.

A couple of years ago, Agenus acquired technology for rapid discovery of certain proteins that aroused the interest of Merck & Co. and Incyte, which entered agreements with Agenus to produce some clinical candidates. Incyte paid Agenus $25 million up front for a handful of candidates that could begin clinical studies, some of which the partners will share costs to develop, and others to be developed by Incyte. The deal is complicated, but in a nutshell, the more Agenus risks developing each candidate, the larger its share of potential profits if it succeeds.

IMAGE SOURCE: AGENUS INC.

More recently, Merck selected a candidate to develop with its own resources. This triggered a $2 million payment to Agenus, with more to come if Merck advances the undisclosed compound through clinical stages, and potential royalties if it reaches pharmacy shelves.

Bluebird's most important collaboration is with oncology giant Celgene. The highly collaborative big biotech has already fronted Bluebird $100 million to discover and develop two candidates through phase 1 studies.

Bluebird began a phase 1 trial with the first candidate -- bb2121, a potential multiple myeloma therapy -- this February. Even more encouraging, Celgene exercised its option to exclusively license the candidate at the beginning of the trial. This means Bluebird doesn't need to pay for further studies but is still entitled to potential payments if it crosses regulatory hurdles, and royalties if it generates sales.