Faculty, Staff and Student Publications

Publication Date

3-17-2025

Journal

Clinical Cancer Research

Abstract

Purpose: Signal transducer and activator of transcription 3 is a transcription factor that is essential for the survival and immune sequestration of cancer cells. We conducted a phase I study of TTI-101, a first-in-class, selective small-molecule inhibitor of signal transducer and activator of transcription 3, in patients with advanced metastatic cancer.

Patients and methods: Patients were treated with TTI-101 orally twice daily in 28-day cycles at four dose levels (DL): 3.2 (DL1), 6.4 (DL2), 12.8 (DL3), and 25.6 (DL4) mg/kg/day ("3+3" design). Three TTI-101 formulations were used in a stepwise manner (NCT03195699).

Results: Sixty-four patients were treated (median age, 63 years; male sex, 52%; median number of prior therapies, 3). No dose-limiting toxicities or fatal treatment-related adverse events (TRAE) were observed. Diarrhea (mostly grade 1/2) was the only TRAE observed in ≥30% of subjects. Five patients experienced grade 3 TRAEs that resolved. TTI-101 showed linear pharmacokinetics from DL1 to DL3, with the pharmacokinetics plateauing at DL3. The recommended phase II dose is 12.8 mg/kg/day (DL3). Of the 41 patients who were evaluable for response, five (12%) had confirmed partial responses (cPR) and 17 (41%) had stable disease. Three (18%) of the 17 patients with hepatocellular carcinoma had a cPR (median time to treatment failure, 10.6 months). Two other cPRs were noted in one patient with ovarian cancer and one patient with gastric cancer.

Conclusions: TTI-101 was well tolerated. cPRs were observed across tumor types. The antitumor activity of TTI-101 monotherapy in patients with advanced, metastatic solid tumors is promising. A phase II study of TTI-101 in hepatocellular carcinoma is currently underway.

Keywords

Humans, Male, Female, Middle Aged, Aged, Neoplasms, STAT3 Transcription Factor, Adult, Administration, Oral, Aged, 80 and over, Antineoplastic Agents, Treatment Outcome

DOI

10.1158/1078-0432.CCR-24-2920

PMID

39792482

PMCID

PMC11911802

PubMedCentral® Posted Date

1-10-2025

PubMedCentral® Full Text Version

Post-print

Published Open-Access

yes

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