The partnership, first inked in 1995 and then reworked in 2010, covers Roche's cancer medicines Rituxan and Gazyva, as well as Roche's multiple sclerosis treatment Ocrevus. It's been lucrative for Biogen as Rituxan was for many years among the industry's top-selling medicines, although rising competition has depressed sales recently.
Over the first nine months of 2021, Biogen received nearly $500 million for its share of pre-tax profits from sales of Rituxan and Gazyva, as well as another $745 million mostly for its share in Ocrevus sales.
For $30 million, Biogen will buy into a drug that could become the first of its type should the FDA see fit to approve it. Mosunetuzumab targets CD20, which is commonly found on the B cells that proliferate in lymphoma, and CD3, a protein found on the T cells the treatment is designed to recruit for battle against the cancer. This dual-targeting ability is a key feature of the design of antibodies known as bispecifics, which drugmakers view as potentially more potent treatments for some tumor types.
Several other treatments targeting CD20 and CD3 are in development by AbbVie, Regeneron and Johnson & Johnson. Roche even has a second molecule bispecific antibody called glofitamab that's also aimed at CD20 and CD3.
Early study results have shown these drugs can, to varying degree, knock back cancer cell proliferation and even result in complete remission in treating diffuse large B-cell lymphoma and follicular lymphoma. So far, the bulk of the clinical evidence for these drugs has come in trials involving people with cancer that's relapsed or become resistant to other treatments.
Under terms of the deal, Biogen will share operating profits and losses to mosunetuzumab in the U.S. in the low- to mid-30% range, and can also receive low single-digit royalties on sales outside the U.S. In Europe, Roche has already submitted the drug to regulators for review.
Salim Syed, an analyst at Mizuho Securities, calculates Biogen's rights could translate to an additional $300 million of revenue based on forecasts of more than $1 billion in peak sales of mosunetuzumab.
In addition to its potential in cancer, mosunetuzumab is being tested in lupus, Biogen noted in its Tuesday statement. Lupus, an inflammatory autoimmune disease, is a focus for Biogen, which has two drugs in late-stage testing.