US pharma giant Pfizer has agreed to acquire Trillium Therapeutics, a publicly listed Canadian clinical stage immuno-oncology company, for $18.5 per share or $2.26 billion in an all-cash deal.

The portfolio of Trillium Therapeutics has biologics that have been designed to boost the ability of patients’ innate immune systems for detecting and killing cancer cells.

The company’s two lead molecules are TTI-622 and TTI-621, which inhibit the signal-regulatory protein α (SIRPα)–CD47 axis — which is becoming an important immune checkpoint in hematological malignancies.

TTI-622 and TTI-621 are SIRPα-Fc fusion proteins that are presently in phase 1b/2 development across various indications, with a focus on the treatment of hematological malignancies.

In clinical studies so far, the SIRPα-Fc fusion proteins had shown activity as monotherapy in relapsed or refractory lymphoid malignancies such as Diffuse Large B-cell Lymphoma (DLBCL), Follicular Lymphoma (FL), Peripheral T-cell lymphoma (PTCL), and other lymphoid malignancies.

Chris Boshoff — Chief Development Officer, Oncology, Pfizer Global Product Development, said: “We are encouraged by the early clinical data for TTI-622 and TTI-621 monotherapy for patients with heavily pretreated lymphoid malignancies and early encouraging activity for TTI-622 in patients with multiple myeloma.

“Just as PD-1 and PD-L1 blockers have proven to be effective immuno-therapeutics for many solid tumors, the SIRPα-CD47 interaction defines a second key immune checkpoint for which disrupting agents are expected to become another important backbone immunotherapy for multiple types of cancer, especially hematological cancers.

“Utilizing Pfizer’s leading research and global development capabilities, we plan to accelerate the clinical development of SIRPα fusion proteins as a potential new scientific breakthrough and explore combinations within our own portfolio and with innovative next-generation medicines for hematological malignancies.”

Pfizer had invested $25 million in Trillium Therapeutics last September as part of the Pfizer Breakthrough Growth Initiative (PBGI).

Dr. Jan Skvarka — CEO of Trillium Therapeutics said: “Trillium has the only known SIRPα–CD47 targeting molecules with clinically meaningful monotherapy responses as well as a strong basis for combination therapies, which is supported by preclinical evidence with a diverse set of therapeutic agents.

“With Pfizer’s global reach and deep capabilities, we believe our programs will advance more quickly to the patients we’ve always aspired to serve. We believe this is a good outcome for patients and our shareholders.”

The acquisition will be executed through a statutory plan of arrangement under the Business Corporations Act (British Columbia). Its closing will be contingent on customary closing conditions, such as approval of 66⅔% of Trillium Therapeutics and court and regulatory approvals.

  Canada, Chris Boshoff, Dr. Jan Skvarka, Follicular lymphoma, hematological malignancies, Immune System, Lymphoma, Multiple myeloma, Oncology, Peripheral T-cell lymphoma, Pfizer, Solid tumors, T-Cell lymphoma, Trillium Therapeutics, TTI-621, TTI-622, USA