Genzyme has shored up its oncology and multiple sclerosis franchise through a new deal with Bayer, of Leverkusen, Germany. Best known for targeting rare genetic disorders, Genzyme is bringing into its stable three approved cancer therapeutics: Fludara (fludarabine) for B-cell chronic lymphocytic leukemia (B-CLL); Leukine (sargramostim), a hematopoietic growth factor used to stimulate the bone marrow following chemotherapy; and Campath (alemtuzumab) for B-CLL. The Cambridge, Massachusetts, company will pay up to $500 million (plus another $150 million after 2011) based on annual revenues, for those three products. Bayer will continue to supply Fludara and Leukine, although Genzyme is acquiring a Leukine-manufacturing plant for $75 million to $100 million and will produce that product itself when the plant is cleared by the US Food and Drug Administration. Perhaps the most interesting aspect of the deal is that Campath is being tested against multiple sclerosis (MS). The companies have been linked over Campath since 2006, but this deal transfers all marketing rights to Genzyme while Bayer continues to support development. Campath, a humanized monoclonal antibody that binds to CD52, has shown promise in phase 2 trials for MS, and is currently in two phase 3 trials. If approved for MS, Bayer could receive up to $1.25 billion, plus further payments related to sales after 2021 (Genzyme retains a buyout option for Bayer's share in 2020 for $900 million). Although Bayer could still co-promote the drug in the US, Genzyme now has primary responsibility in MS. But don't let the high milestone payments deceive—all those moving parts in essence mean the deal is more about “altering accounting and delineating development responsibilities” rather than making a strategic shift for Genzyme, says Brian Abrahams, analyst with Oppenheimer in New York.