Sorry, you need to enable JavaScript to visit this website.
Pfizer Oncology
Loading...

The safety and efficacy of this agent(s), or use in this setting, has not been established or is subject to confirmation. For an agent(s) whose safety and efficacy has not been established or confirmed, future regulatory approval or commercial availability is not guaranteed.

Maplirpacept (TTI-622 | PF-07901801)

Geo Regions

Important Notice Regarding the Scientific Information You Have Requested

You are being redirected to the scientific presentations section. The information provided here relate to investigational assets. The safety and efficacy of the unapproved assets has not been proven. 

Please acknowledge that you understand this before proceeding.

Maplirpacept (TTI-622 | PF-07901801)

Maplirpacept (TTI-622 | PF-07901801) is an investigational compound. Its safety and efficacy have not been established.

Share to an HCP

Overview + Rationale

RATIONALE FOR CANCER TARGET

  • CD47, or integrin-associated protein, is a cell surface ligand expressed in low levels by nearly all cells of the body. It plays an integral role in various immune responses as well as autoimmunity, by sending a “don’t eat me” signal to prevent phagocytosis
  • CD47 is overexpressed in various hematological malignancies and its interaction with Signal Regulatory Protein (SIRP)α on phagocytic cells prevents phagocytosis of cancer cells
  • Additionally, it is expressed by different cell types in the tumor microenvironment and is required for establishing tumor metastasis. Overexpression of CD47 is thus often associated with poor clinical outcomes
  • CD47 blockade promotes both innate (macrophage phagocytosis) and adaptive immunity (T cell responses)

OVERVIEW

  • Maplirpacept (TTI-622 | PF-07901801) is a fusion protein designed to enhance phagocytosis and antitumor activity by preventing CD47 from delivering its inhibitory signal as well as generating a moderate pro-phagocytic signal via IgG4 Fc
  • Maplirpacept minimally binds to human red blood cells

Mechanism of Action

Stage of Development

small icon for Hematologic Cancer

R/R Diffuse Large B-Cell Lymphoma (DLBCL) Transplant Ineligible

Phase 1b/2 Combination*

Phase 2 Combination§
Hem

Multiple Myeloma

Phase 1B Combination

Phase 1 Combination†
This information is current as of August 5th 2025.

* NCT05626322 is Closed to Enrollment §Study Sponsored by Mayo Clinic. †Study Sponsor MSK, Closed to Enrollment

CD=cluster of differentiation; Fc=fragment crystallizable; FcγR=Fc gamma receptor; IgG=immunoglobulin G; R/R=relapsed/refractory;  SIRPα=signal regulatory protein alpha.

REFERENCES:  Eladl, E., J Hematol Oncol 13, 96 (2020); Thompson et al. Journal of Clinical Oncology 35, no. 15_supp https://medicalxpress.com/news/2017-02-potential-cancer-treatment-cancer-engulfing-cells.html   Accessed Nov.22,2021; Patel et al.  ASH 2020 Poster. 1191   https://ash.confex.com/ash/2020/webprogram/Paper136607.html.  Accessed Nov. 23, 2021l  Trillium R&D Day “Opening a New Chapter in Trillium’s Evolution,” April 2021; Trillium Therapeutics Annual Information Form for the Year Ending December 31, 2019; Chao MP, et al. Front Oncol. 2020;9:1380. 2. Pfizer Inc. Data on file. 3. Dizman N, Buchbinder EI. Cancers (Basel). 2021;13:6229; Clinicaltrials.gov. https://clinicaltrials.gov/study/NCT05896163; https://clinicaltrials.gov/study/NCT05675449; https://clinicaltrials.gov/study/NCT05507541 https://clinicaltrials.gov/study/NCT05139225  Accessed July 7, 2025.