Seattle Genetics sets $614M buyout of Cascadian and its breast cancer program

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Seattle Genetics opted for the deal in order to bulk out its pipeline. (Image: TaxRebate.org.uk)

After a multibillion-dollar deal to buy Immunomedics fell through last May, Seattle Genetics has scaled down its spending as it sets up a $614 million deal for Cascadian Therapeutics.

The biotech gets in return for its cash, worth $10 a share (a 69% premium from its shares yesterday), Cascadian’s tucatinib, an oral tyrosine kinase inhibitor, which is pivotal midstage tests for advanced HER2 breast cancers. It’s also slated for tests in other HER2 cancers, such as colon cancer.

This comes after Seattle last summer called a halt to all clinical testing of vadastuximab talirine (SGN-CD33A) after seeing a higher rate of patient deaths with the drug in a phase 3 trial.

Seattle was on the hunt for a deal, and last year looked to have one with Immunomedics in the bag. The deal would have added a highly regarded potential blockbuster to Seattle's portfolio: sacituzumab govitecan (IMMU-132) for breast and lung cancer. But that deal fell apart after an Immunomedics shareholder revolt that also claimed the scalps of its CEO and founder.

RELATED: Seattle kills off $2B Immunomedics deal as biotech’s CEO and founder axed

The biotech hopes this cheaper deal will still help bulk out its pipeline. Of course, a number of HER2-positive medications are already on the market for this type of cancer, including Roche's aging Herceptin, which is now under biosimilar threat, as well as its Perjeta and Kadcyla, and Novartis' Tyverb. 

“This acquisition would enhance our late-stage clinical pipeline with a potentially best-in-class, orally available and highly selective TKI for patients with HER2-positive metastatic breast cancer,” said Clay Siegall, Ph.D., president and CEO at Seattle.

“Tucatinib would complement our existing pipeline of targeted cancer therapies, provide a third late-stage opportunity for a commercial product in solid tumors and expand our global efforts in breast cancer. It also leverages our broad expertise and resources to advance and expand the tucatinib program for patients.

“Beyond breast cancer, we believe there may be opportunities for tucatinib in other tumor types, such as HER2-positive metastatic colorectal cancer. Cascadian’s pipeline also includes a preclinical immuno-oncology agent. We look forward to welcoming the team at Cascadian Therapeutics and continuing the momentum of the tucatinib development program.”

The biotech also partners with Takeda on Adcetris (brentuximab vedotin) for relapsed Hodgkin lymphoma and anaplastic large cell lymphoma. Today, within its financials, Seattle said it made around $300 million from the med in North America.

Scott Myers, president and chief of Cascadian Therapeutics (formerly Oncothyreon), added: “This agreement represents a very positive outcome for patients with HER2-expressing cancers, our employees and for our stockholders.

“Seattle Genetics has the development and commercial capabilities and the resources needed to more fully realize the potential of tucatinib as a new best-in-class treatment option for metastatic breast cancer, colorectal cancer and potentially for other indications.”