It was shaping up to be a fight amongst the little guys. In September, Allos Therapeutics (NASDAQ:ALTH) received Food and Drug Administration approval for Folotyn to treat peripheral T-cell lymphoma (PTCL), and last month, privately held Gloucester Pharmaceuticals got Istodax approved to treat related cutaneous T-cell lymphoma (CTCL).

Istodax is in a clinical trial for PTCL and Folotyntm is in a trial for CTCL, so a head-to-head fight on multiple fronts between the one-drug wonders seemed inevitable. That is, until powerhouse Celgene (NASDAQ:CELG) threw its muscle in the ring. The company said today that it will buy Gloucester for $640 million.

Technically, Celgene is paying only $340 million in cash up front, but it's on the hook for up to $300 million more in milestone payments for additional regulatory approvals in the U.S. and elsewhere. Celgene's investors had better hope it has to pay those additional milestones; being approved for just CTCL in the U.S. would be a fairly limited market.

With a much stronger adversary, Allos fell today. A lot. A full 12.5%, in fact.

If it falls much further, it'll look like a pretty good acquisition target for a large pharma looking to even out the playing field. Japan's Takeda Pharmaceuticals bought Celgene's former rival, Millennium Pharmaceuticals, last year. Perhaps it would like to double up? Johnson & Johnson (NYSE:JNJ) sells Takeda's Velcade outside the United States, so it's a possible contender as well.

Another possible suitor for Allos could be Onyx Pharmaceuticals (NASDAQ:ONXX). It's not exactly a powerhouse in marketing blood-cancer drugs -- in fact, it doesn't have any experience in the field. But Onyx recently purchased Proteolix for its phase 2 multiple myeloma drug, and getting an established sales force for its new acquisition would be a good move.

Until a suitor comes along, Allos needs to keep a stiff upper lip. It has a lead on Celgene in PTCL, and it'll need to use this time very wisely. There's no time for sulking.

Motley Fool Rule Breakers is always on the hunt for hot drug stocks and other cutting-edge picks. See all of our latest discoveries with a free 30-day trial subscription.

Fool contributor Brian Orelli, Ph.D., doesn't own shares of any company mentioned in this article. Johnson & Johnson is a selection of the Income Investor newsletter service. The Fool has a disclosure policy.