Theratechnologies to Present Preliminary Safety and Efficacy Data from Phase 1 Trial of Sudocetaxel Zendusortide in Heavily Pretreated Cancer Patients at ASCO 2023 - Seite 2

Study details and results

Part 1 of the study enrolled 18 adults with a confirmed diagnosis of a metastatic or advanced-stage solid tumor that is refractory to standard therapies (average of 8 prior lines of therapies). The starting dose of 30 mg/m² every 3 weeks (Q3W) was selected based on sudocetaxel zendusortide preclinical data. Among participants in Part 1, one patient with endometrial cancer experienced SD for 233 days (33 weeks), a second patient with prostate cancer had SD that lasted for 119 days (17 weeks), and a third patient with ovarian cancer experienced SD for 295 days (42 weeks).

Eighteen additional patients were enrolled into the 300 mg/m² Q3W dose expansion cohort (Part 2). In an interim efficacy and safety analysis of the 300 mg/m² dose cohort from Parts 1 and 2 (n=25), five of six patients (83%) with ovarian cancer had a best overall response (BOR) of either PR (n=1) or SD (n=4). In the triple-negative breast cancer (TNBC) population, three of four patients (75%) had a BOR of SD, with one patient experiencing SD for at least four cycles and continued clinical benefit up to at least 24 weeks. In the two patients with prostate cancer, one experienced a PR.

Sudocetaxel zendusortide doses below 300 mg/m² were well-tolerated in Part 1 of the trial, which established the maximum tolerated dose (MTD) and dose-limiting toxicities at 360 mg/m² and 420 mg/m², respectively. Based on those results, investigators selected a 300-mg/m² dose for Part 2 (dose expansion) of the basket trial, to determine the safety and efficacy of sudocetaxel zendusortide in patients with multiple tumor types with high expression of the sortilin (SORT1) receptor. At 300 mg/m², the most common treatment-related adverse events (>20%) were ocular changes, neuropathy, gastrointestinal disturbances, and musculoskeletal complaints, with Grade 3 or greater toxicities at a frequency of ≤12%.

Poster presentation details:

Title: “Sudocetaxel zendusortide (TH1902), a novel sortilin-receptor (SORT1)-targeting peptide-drug-conjugate (PDC) in patients (pts) with advanced solid tumors: Results from part 1 (dose-escalation) of a phase 1, open-label study”

Lead author: Funda Meric-Bernstam, M.D., Chair of the Department of Investigational Cancer Therapeutics at The University of Texas MD Anderson Cancer Center

Abstract number: 3089

Session Date and Time: Saturday June 3, 2023, Developmental Therapeutics - Molecularly Targeted Agents and Tumor Biology, 8:00-11:00 CDT

About SORT1+ Technology and Sudocetaxel Zendusortide (TH1902)