About Trillium Therapeutics

Trillium Therapeutics Inc. operates as a clinical stage immuno-oncology company. The company is developing innovative therapies for the treatment of cancer. The company focuses on developing inhibitors of CD47, a checkpoint of the innate immune system. CD47 is emerging as a promising next generation immuno-oncology target following the scientific, clinical and commercial success of T-cell checkpoint inhibitors. The company has two product candidates in early stages of clinical development – TTI-622 (a SIRPa-IgG4 Fc fusion protein); and TTI-621 (a SIRPa-IgG1 Fc fusion protein). TTI-622 consists of the CD47-binding domain of human SIRPa linked to the Fc region of IgG4. It is designed to enhance macrophage-mediated phagocytosis and anti-tumor activity by blocking the CD47 ‘don’t eat me’ signal and generating a moderate activating ‘eat’ signal via the IgG4 Fc. TTI-621 consists of the same CD47-binding domain as TTI-622 but linked to the Fc region of IgG1, which generates a stronger ‘eat’ signal than IgG4. It is anticipated that the distinct ‘eat’ signals will result in different tolerability profiles, thus achieving different levels of drug exposure and CD47 blockade in patients. Specifically, TTI-622 is expected to achieve a high level of CD47 blockade and deliver a moderate ‘eat’ signal, whereas TTI-621 is expected to achieve a lower level of CD47 blockade but deliver a strong ‘eat’ signal. Both agents have been well tolerated and have demonstrated monotherapy activity in patients with B- and T-cell lymphomas. In 2020, the company released an update on the ongoing TTI-622 study. In the phase 1a portion of the study, the safety assessment of the 8 mg/kg dosing cohort has been successfully completed. In 2020, the company released an update on the TTI-621 intravenous study. The company reported that the study was dosing at the 2.0 mg/kg level, and the protocol allows for higher dosing if appropriate. The company has also conducted an open-label phase 1 trial in which TTI-621 was delivered by intratumoral injection in patients with relapsed and refractory, percutaneously-accessible cancers. The company’s main focus in the immediate term is to identify the maximum tolerated or recommended phase 2 doses for both TTI-622 in the ongoing study NCT03530683 and TTI-621 under the revised dose-limiting toxicity (DLT) criteria in Part 4 of study NCT02663518. License agreement with University Health Network (UHN) and The Hospital for Sick Children (HSC) In 2010, the company entered into a license agreement with the UHN and HSC pursuant to which it licensed intellectual property relating to methods and compounds for the modulation of the SIRPa - CD47 interaction for therapeutic cancer applications. The license agreement requires the company to use commercially reasonable efforts to commercialize the licensed technology. Strategy The key elements of the company’s strategy are to rapidly advance the clinical development of TTI-622 and TTI-621; focus its TTI-622 and TTI-621 clinical programs on promising cancer indications; focus its TTI-622 and TTI-621 clinical programs on promising combinations. Intellectual Property The company controls two main patent families relating to SIRPa. One family claims the two species of SIRPaFc (TTI-621 and TTI-622) in clinical trials and their anti-cancer use. These patent rights are owned outright by the company and patent filings have been arranged in the major pharmaceutical markets. In October 2020, the company announced that it received a Notice of Allowance from the United States Patent and Trademark Office (USPTO), for the patent application covering TTI-622 composition of matter. In February 2021, this patent was issued as U.S. No. 10,906,954. This patent has claims that cover TTI-622 composition of matter comprising human SIRPa linked to an IgG4 Fc region, as well as claims covering pharmaceutical compositions that contain TTI-622. A composition of matter patent for TTI-621 (SIRPa linked to an IgG1 Fc) has already been granted in the U.S. (U.S. 9,969,789). Composition of matter patents are also granted in Europe, Australia, Japan and China. Patents emerging from this family begin to expire in 2033. A second SIRPa patent family was in-licensed on an exclusive basis from co-owners UHN and HSC and is a method of use application. This family has been filed in the major markets. In October 2020, the company announced that it received a Notice of Allowance from the United States Patent and Trademark Office (USPTO) for this application, which was issued U.S. Patent No. 10,907,209 on February 2, 2021. This patent provides coverage for the use of SIRPaFc biologics to treat all CD47+ cancer cells and tumors, including hematologic and solid cancers. The claims cover the use of various forms of SIRPa to treat CD47-positive cancers. Method of use patents have also been granted in Japan, Canada and Australia. Patents in this family begin to expire in the year 2029. The foregoing patent granted in Europe was revoked following an opposition and is under appeal. The company has also filed for patent protection covering additional inventions relating to SIRPa, including anti-cancer drug combination therapies that utilize SIRPaFc, and biomarkers that identify SIRPaFc responders. Research and Development For the year ended December 31, 2020, the company’s research and development expenses were $25.3 million. History The company was founded in 2004. The company was incorporated under the Business Corporations Act (Alberta) in 2004. It was formerly known as Stem Cell Therapeutics Corp. and changed its name to Trillium Therapeutics Inc. in 2014.