Theratechnologies Inc. announced completion of enrollment of the first six participants in Part 3 of its Phase 1 clinical trial of sudocetaxel zendusortide in patients with advanced ovarian cancer. Sudocetaxel zendusortide, also known as TH1902, is an investigational, first-in-class peptide-drug conjugate (PDC) that targets the sortilin receptor (SORT1) and aims to expedite the internalization and delivery of the cytotoxic payload (docetaxel) directly into cancer cells. Theratechnologies announced dosing of the first patient in Part 3 of the Phase 1 trial in October 2023.

In June 2023, the U.S. Food and Drug Administration (FDA) accepted the Company?s amended protocol for the Phase 1 trial, which is designed to optimize the dosing, improve the therapeutic window and extend the duration of therapy of sudocetaxel zendusortide. The amendment, which the Company submitted in May 2023, also narrows the patient population to focus on individuals with high-grade serous ovarian cancer, including high-grade peritoneal or fallopian tube cancer, or high-grade endometrioid cancer -- a population in which sudocetaxel zendusortide has demonstrated preliminary efficacy. After establishing the safety of the initial dose in the first six patients for a period of three months, the enrollment of the next cohort of six patients at a higher dose will be initiated.

Sudocetaxel zendusortide is a first-of-its-kind sortilin receptor (SORT1)-targeting PDC, and the first compound to emerge from the Company?s broader licensed oncology platform. A new chemical entity, sudocetaxel zendusortide employs a cleavable linker to conjugate (attach) a proprietary peptide to docetaxel, a well-established cytotoxic chemotherapeutic agent used to treat many cancers. The FDA granted Fast Track designation to sudocetaxel zendusortide as a single agent for the treatment of all sortilin-positive recurrent advanced solid tumors that are refractory to standard therapy.

Sudocetaxel zendusortide is currently being evaluated in a Phase 1 clinical trial. Theratechnologies has established the SORT1+ Technology? platform as an engine for the development of PDCs that target SORT1, which is expressed in multiple tumor types.

SORT1 is a ?scavenger? receptor that plays a significant role in protein internalization, sorting, and trafficking. Expression of SORT1 is associated with aggressive disease, poor prognosis, and decreased survival.

It is estimated that SORT1 is expressed in 40% to 90% of endometrial, ovarian, colorectal, triple-negative breast (TNBC), and pancreatic cancers, making this receptor an attractive target for anticancer drug development.