Takeda Pharmaceutical said it is acquiring San Diego-based Intellikine for $190 million in cash and as much as $120 million more should it reach certain clinical milestones. The privately held startup is focused on the discovery and development of innovative, small molecule drugs targeting the PI3K/mTOR pathway, one of the hottest targets being pursued by a slew of big pharmaceutical and biotech companies for the treatment of cancer and other serious diseases.

GlaxoSmithKline, Novartis, Gilead Sciences, and Roche are among the companies developing drugs that target the PI3K pathway, which has been shown to be a central signaling pathway for cellular proliferation, survival, and trafficking.

Started just five years ago, Intellikine had raised $41 million from a group of investors that includes traditional venture capital firms and corporate venture firms. Its most advanced drug candidate, INK128, has generated encouraging data in several early stage studies and is expected to enter mid-stage clinical trials next year. Intellikine’s second drug candidate, INK1117, entered into human clinical testing in September 2011.

Millennium, Takeda’s cancer division, will be responsible for the global development of Intellikine’s portfolio. “INK128 and INK1117 are potential best-in-class inhibitors of critical pathways driving cancer cell growth," says Deborah Dunsire, president and CEO of Millennium. “As single agents or in different combinations with novel molecules within our robust pipeline, we anticipate that these assets will be able to deliver transforming therapies to cancer patients.”

Takeda’s acquisition of Intellikine is the second buyout of a U.S. firm focused on PI3K kinase inhibitors in 2011. Gilead acquired Calistoga Pharmaceuticals in February, paying $375 million upfront and promising up to $225 million in potential milestones for its mid-stage cancer drug candidate and pipeline targeting the PI3K pathway.

Biosimilars deals are ramping up as the year comes to an end and drugmakers aim to share in the potential revenues from copies of biologic drugs losing patent protection in the coming years. Amgen is collaborating with Watson Pharmaceuticals, in a deal that seems a copycat version of one struck just a couple of weeks ago between Biogen Idec and Samsung. (Burrill & Company, publisher of The Burrill Report, served as an advisor to Samsung on the transaction.) In both cases, the biotechs will contribute their biologics expertise and take a minority stake in a biosimilars collaboration/joint venture. In both cases, the joint venture will not pursue biosimilars of the biotech’s proprietary products

Baxter International also jumped into the biosimilars arena through collaboration with Momenta Pharmaceuticals to develop and commercialize follow-on biologics. Baxter will leverage its clinical development, biologic manufacturing, sterile injectable, and commercial expertise, while Momenta will provide its capabilities in high-resolution analytics, characterization, and product and process development.

Baxter will pay Momenta $33 million upfront for up to six follow-on biologic compounds, plus make additional payments over the next several years for the development of the compounds, contingent upon the achievement of technical, development, and regulatory milestones with respect to all six products.

“As biologics have become an increasingly important part of patient care, the collaboration with Momenta allows us to tap both companies’ expertise to expand access to these important therapies,” says Ludwig Hantson, president of Baxter’s BioScience business. “The collaboration complements Baxter’s early-stage pipeline and allows the company to expand its leadership in biologics at a time when the global regulatory pathway for approval is becoming more clear.”