TTI-621 is under clinical development by Pfizer and currently in Phase I for Cutaneous T-Cell Lymphoma. According to GlobalData, Phase I drugs for Cutaneous T-Cell Lymphoma have an 85% phase transition success rate (PTSR) indication benchmark for progressing into Phase II. GlobalData’s report assesses how TTI-621’s drug-specific PTSR and Likelihood of Approval (LoA) scores compare to the indication benchmarks. Buy the report here.

GlobalData tracks drug-specific phase transition and likelihood of approval scores, in addition to indication benchmarks based off 18 years of historical drug development data. Attributes of the drug, company and its clinical trials play a fundamental role in drug-specific PTSR and likelihood of approval.

TTI-621 overview

TTI-621 (SIRPa Fc) is under development for treatment of relapsed or refractory lymphomas, solid tumors like indolent B-cell lymphoma, aggressive B-cell lymphoma, cutaneous T-cell lymphoma, peripheral T-cell lymphoma, chronic lymphocytic leukemia, relapsed or refractory multiple myeloma, acute myeloid leukemia, small-cell lung cancer, acute lymphoblastic leukemia, myelodysplastic syndrome, myeloproliferative neoplasms, diffuse large B-cell lymphoma, leiomyosarcoma, soft-tissue sarcomas including high-grade leiomyosarcoma, undifferentiated pleomorphic sarcoma, myxofibrosarcoma, dedifferentiated liposarcoma, angiosarcoma, follicular lymphoma, primary mediastinal (thymic) large B-cell lymphoma and epithelioid sarcoma. It is administered through intratumoral and intravenous route. SIRPaFc (TTI-621) is a fusion protein that consists of the CD47-binding domain of human SIRPa linked to the Fc region of a human immunoglobulin (IgG1). The drug candidate targets CD47. It was also under development for the treatment of mycosis fungoides, Sezary syndrome, melanoma (intratumoral).

Pfizer overview

Pfizer discovers, develops, manufactures and commercializes biopharmaceuticals. The company offers products to treat various conditions such as cardiovascular, metabolic and pain, cancer, inflammation, immune disorders and rare diseases. It also provides sterile injectable pharmaceuticals, biosimilars, active pharmaceutical ingredients (APIs) and contract manufacturing services. Pfizer sells its products through wholesalers, retailers, hospitals, clinics, government agencies and pharmacies. It has major manufacturing facilities in India, China, Japan, Ireland, Italy, Belgium, Germany, Singapore, and the US. The company provides its products in North America, South America, Asia-Pacific, Australia, Europe, Africa and the Middle East. Pfizer is headquartered in New York, the US.

For a complete picture of TTI-621’s drug-specific PTSR and LoA scores, buy the report here.


GlobalData, the leading provider of industry intelligence, provided the underlying data, research, and analysis used to produce this article.

GlobalData’s Likelihood of Approval analytics tool dynamically assesses and predicts how likely a drug will move to the next stage in its clinical pathway (PTSR), as well as how likely the drug will be approved (LoA). This is based on a proprietary algorithm built from the drugs’ sales forecast, regulatory milestones, cost forecasts, WACC rate and other proprietary data sources found on GlobalData’s Pharmaceutical Intelligence Center.