Bayer Joins with Seattle Genetics in Antibody-Drug Conjugate Deal

Xconomy Seattle — 

Bayer HealthCare has signed a new deal with Bothell, WA-based Seattle Genetics (NASDAQ: SGEN) for access to its methods of creating cancer drugs that home in on tumors and then deliver a toxic dose to their cells.

The two partners today announced a collaboration worth as much as $520 million to the Seattle company, which has also licensed its technology to an array of other big players include Genentech, GlaxoSmithKline, Millennium, and Pfizer. Bayer, a repeat customer, struck its first partnership with Seattle Genetics in 2004.

Seattle Genetics is one of the pioneers in boosting the power of antibody drugs by making antibody-drug conjugates (ADCs). These combine an antibody that recognizes and sticks to cancerous cells with a toxic drug payload that is selectively released in those cells.

Bayer will pay as much as $20 million upfront to gain worldwide rights to pair Seattle Genetics’ cell-killing agents called auristatins with antibodies focused on an undisclosed number of oncology targets. The synthetic auristatin cell toxins are as much as 1000 times more potent than traditional chemotherapy drugs, the Seattle company says. To use such drugs safely, the company has developed stable systems that link the toxin to the antibody and release it only inside cancer cells. Ideally, ADCs guard normal cells and kill tumor cells only.

Seattle Genetics could receive up to $500 million from Bayer in additional milestone payments and royalties on worldwide sales of products developed through the new collaboration. Bayer will conduct the research, development, manufacturing and commercialization of these products.

Bayer Healthcare’s own antibody-drug conjugate program is a key focus for the company, a unit of drug giant Bayer AG, based in Leverkusen, Germany. The new deal with Seattle Genetics will strengthen that pipeline portfolio, said Andreas Busch, Bayer’s head of global drug discovery, in a written statement.

“Antibody-drug conjugates are promising approaches in oncology which can attack tumor cells in a much more targeted way for cancer patients, such that healthy cells are less severely affected,” Busch said.

The recent track record of Seattle Genetics and its partners has heightened interest in ADCs. The Seattle company markets its own antibody-drug conjugate, brentuximab vedotin (Adcetris), which was approved by the FDA in 2011 for certain forms of lymphoma. The company is also testing other proprietary ADC drug candidates. Roche unit Genentech showcased some encouraging results for two pipeline drugs using Seattle Genetics technology at the American Society of Clinical Oncology’s annual meeting this month. Genentech had already won FDA approval in February for its new breast cancer drug, ado-trastuzumab emtansine (Kadcyla), which it developed with technology from Seattle Genetics’ rival in the ADC field, Waltham, MA-based ImmunoGen (NASDAQ: IMGN).

Seattle Genetics and its collaborators now have more than 15 ADCs in clinical testing, said company executive Natasha Hernday in a written statement. “We have the potential to receive more than $3.5 billion in future milestones plus royalties from these strategic alliances,” Hernday said.