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.