Pfizer and Trillium Therapeutics announced that the companies have entered into a definitive agreement under which Pfizer will acquire Trillium, a clinical-stage immuno-oncology company developing innovative therapies for the treatment of cancer. Under the terms of the agreement, Pfizer will acquire all outstanding shares of Trillium not already owned by Pfizer for an implied equity value of US $ 2.26 billion, or US $ 18.50 per share, in cash. This represents a 118% premium to the 60-day weighted average price for Trillium.

In September 2020, as part of the Pfizer Breakthrough Growth Initiative (PBGI), Pfizer had invested US $ 25 million in Trillium.

Trillium’s portfolio includes biologics that are designed to enhance the ability of patients’ innate immune system to detect and destroy cancer cells. Its two lead molecules, TTI-622 and TTI-621, block the signal-regulatory protein α (SIRPα)–CD47 axis, which is emerging as a key immune checkpoint in hematological malignancies. TTI-622 and TTI-621 are novel, potentially best-in-class SIRPα-Fc fusion proteins that are currently in Phase 1b/2 development across several indications, with a focus on haematological malignancies.

“Today’s announcement reinforces our commitment to pursue scientific breakthroughs with the addition of potentially best-in-class molecules to our innovative pipeline,” said Andy Schmeltz, Global President & General Manager, Pfizer Oncology. “The proposed acquisition of Trillium builds on our strong track record of leadership in Oncology, enhancing our haematology portfolio as we strive to improve outcomes for people living with blood cancers around the globe. Our deep experience in understanding the science of blood cancers, along with the diverse knowledge base we have developed across our growing haematology portfolio of eight approved and investigational therapies, provide us with a foundation to advance these important potential medicines to patients who need them.”

Haematological malignancies are cancers that affect the blood, bone marrow, and lymph nodes. This classification includes various types of leukaemia, multiple myeloma, and lymphoma. More than 1 million people worldwide were diagnosed with blood cancer in 2020, representing almost 6% of all cancer diagnoses globally. In 2020, more than 700,000 people worldwide died from a form of blood cancer.

“We’re delighted to announce Pfizer’s proposed acquisition of Trillium. Today’s announcement reflects Trillium’s potentially best in class SIRPα–CD47 status and contribution to immuno-oncology,” said Dr. Jan Skvarka, Chief Executive Officer of Trillium. “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.”

In clinical studies to date, TTI-622 and TTI-621 have demonstrated activity as monotherapy in relapsed or refractory lymphoid malignancies, including Diffuse Large B-cell Lymphoma (DLBCL), Peripheral T-cell lymphoma (PTCL), Follicular Lymphoma (FL), and other lymphoid malignancies. As of July 26, 2021, Phase 1 data for TTI-622 in 30 response-evaluable patients have shown deep and durable responses in heavily pretreated patients, including two complete responses (CRs), one lasting over 114 weeks, with responses ongoing. TTI-622 and TTI-621 are currently the only known CD47-targeted molecules that have demonstrated meaningful single-agent activity and CRs in multiple haematological malignancies. Thus far, adverse events (AEs) reported with TTI-622 and TTI-621 have been manageable. Related Grade 3 and 4 AEs with TTI-622 were rare and limited to transient cytopenias. In particular, the molecules demonstrate minimal red blood cell binding and few reported cases of anaemia, an observed risk with other CD47-targeted approaches.