Pfizer invested $25m in Trillium in September as part of the Pfizer Breakthrough Growth Initiative. Pfizer will now acquire all outstanding shares it does not already own, valuing Trillium at $2.26bn.
The company was formed in Ontario, Canada; and now has offices in both Ontario and Cambridge, Massachusetts. 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 hematological malignancies.
Hematological malignancies are cancers that affect the blood, bone marrow, and lymph nodes. This classification includes various types of leukemia, multiple myeloma, and lymphoma. More than 1 million people worldwide were diagnosed with a 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.
“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 hematology 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 hematology portfolio of eight approved and investigational therapies, provide us with a foundation to advance these important potential medicines to patients who need them.”
Clinical studies have shown TTI-622 and TTI-621 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.
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 (data as of July 26).
“TTI-622 and TTI-621 are currently the only known CD47-targeted molecules that have demonstrated meaningful single agent activity and CRs in multiple hematological malignancies,” notes Pfizer.
“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 anemia, an observed risk with other CD47-targeted approaches.”
Further data are to be shared at an upcoming medical conference.