Massachusetts-based biotechnology company Genzyme Corporation has entered into an agreement to acquire the worldwide rights to Campath (alemtuzumab) from Bayer HealthCare, a manufacture of health products for people and animals, giving Genzyme primary responsibility for the development and commercialization of this potential break-though treatment for multiple sclerosis.

Bayer will continue to fund a portion of alemtuzumab’s development in multiple sclerosis (MS) and will retain an option to co-promote the product in MS upon approval.

In addition, Genzyme will assume sole responsibility for worldwide sales and marketing for Campath in B-cell chronic lymphocytic leukemia (CLL), where it is indicated for use as a single agent in first-line and previously-treated patients with this disease.

Bayer will retain the right to develop and commercialize alemtuzumab in solid organ transplant indications.

Under the terms of the agreement, Genzyme will lead the development program. Bayer, which has been co-developing alemtuzumab in MS with Genzyme, will continue to fund development at current levels until the investigational compound is approved for this indication.

After approval, Bayer will receive payments contingent on annual revenue until $1.25 billion in payments is realized.

The agreement includes a ten-year time cap on payments. Bayer may also receive future milestone payments as a percentage of worldwide sales beginning in 2021 if Genzyme does not exercise a buyout option in 2020 for up to $900 million.