05:10 PM EDT, 05/23/2024 (MT Newswires) -- Theratechnologies Inc. ( THTX ) , a biopharmaceutical company focused on the development and commercialization of innovative therapies, was at last look up near 5% in US after hours Thursday as it announced Phase 1 data "demonstrating signs of long-term efficacy and a manageable safety profile of its lead investigational peptide drug conjugate (PDC) candidate, sudocetaxel zendusortide (TH1902), in patients with solid tumors".

This comes after the company saw its stock drop 7.5% in regular U.S. trade today.

Thursday's statement from the company noted the data will be presented in a poster session on June 1 at the 2024 American Society of Clinical Oncology (ASCO) annual meeting, which is taking place May 31-June 4, 2024, in Chicago, IL.

According to the statement, in an updated analysis from Parts 1 and 2 of an ongoing Phase 1 clinical trial, sudocetaxel zendusortide induced durable disease stabilization (up to 45 weeks) lasting beyond treatment completion. It said the results "suggest a unique, multimodal mechanism of action distinct from other cancer therapeutics, including induction of immune cell infiltration even in "cold" tumor models, inhibition of vasculogenic mimicry, targeting of chemotherapy-resistant cancer stem cells, and activation of the cGAS/STING immune pathway, among other actions". Investigators, it added, "observed an early efficacy signal primarily in female cancers (ovarian cancer, endometrial cancer, triple-negative breast cancer [TNBC]), with seven of 16 participants (44%) achieving a clinical benefit rate (complete response + partial response + stable disease), as confirmed via Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1."

The poster presentation, which constitutes the first report of long-term efficacy, safety, and pharmacokinetic (PK) data from the Phase 1 study, also suggests that sudocetaxel zendusortide has a manageable safety profile when dosed at 300mg/m2, with few Grade 3 adverse events (AEs), Thursday's statement noted,

"The initial long-term Phase 1 data further validate and expand upon the preliminary evidence of antitumor activity with sudocetaxel zendusortide in individuals with solid tumors," said Ira Winer, a member of the Gynecologic Oncology and Phase 1 Clinical Trials Multidisciplinary Teams at Karmanos Cancer Center and Associate Professor of Oncology at Wayne State University. "It is highly unusual to see such long-lasting disease stabilization even after treatment cessation in patients with advanced disease. These updated data provide an informative baseline as we seek to optimize the dose of this novel peptide-drug conjugate in patients with platinum-resistant ovarian cancer in the next stage of the Phase 1 trial."