On May 30, 2024 Actym Therapeutics, reported that the U.S. Food and Drug Administration (FDA) has approved its Investigational New Drug (IND) application to start a Phase 1 clinical trial of its lead drug candidate, ACTM-838 (Press release, Actym Therapeutics, MAY 30, 2024, View Source [SID1234643883]). The open-label monotherapy dose escalation study is designed to evaluate the safety, tolerability, payload delivery, and preliminary anti-tumor activity of escalating doses of ACTM-838, which represents the first drug candidate based on the company’s proprietary S. Typhimurium-Attenuated Cancer Therapy (STACT) platform to reach the clinic. ACTM-838 delivers immunomodulatory payloads, engineered IL-15plex (IL-15/ IL-15Ra) and STING, specifically to tumor-resident phagocytic antigen-presenting cells (APCs) in the tumor microenvironment (TME).
Schedule your 30 min Free 1stOncology Demo!
Discover why more than 1,500 members use 1stOncology™ to excel in:
Early/Late Stage Pipeline Development - Target Scouting - Clinical Biomarkers - Indication Selection & Expansion - BD&L Contacts - Conference Reports - Combinatorial Drug Settings - Companion Diagnostics - Drug Repositioning - First-in-class Analysis - Competitive Analysis - Deals & Licensing
Schedule Your 30 min Free Demo!
"The immunosuppressive TME is a key challenge in the treatment of solid tumors, limiting the efficacy of many potentially effective anticancer drugs. Actym Therapeutics has developed an innovative technology to specifically deliver and express constitutively active STING in tumor-resident myeloid cells using a systemically administered therapy. IL-15plex expression adds complementary activity on B, T, and NK cells, achieving durable anti-tumor immunity," said Jason J. Luke, MD, FACP, a leading international physician-scientist specializing in the clinical development of immunotherapies for solid tumors. "Actym’s approach to modulating the TME has a unique potential to overcome these immunological barriers. Their lead candidate, ACTM-838, was shown to be safe and effective in preclinical studies and is now ready to enter the clinic."
"The IND clearance for ACTM-838 is a major milestone for Actym and potentially a significant step forward in harnessing the power of immunotherapy to treat patients with solid tumors more effectively," said Tom Smart, CEO of Actym. "It is terrific to see the vision and impressive work pioneered by Actym’s founders translated into a promising clinical-stage asset. As we advance our lead clinical program, we also look forward to further expanding the potential applications of our STACT biological platform by developing new product candidates in-house and in collaboration with pharmaceutical companies."
The Phase 1 (NCT06336148) open-label monotherapy dose escalation study with ACTM-838 will be conducted at clinical sites in the United States and Australia and will enroll patients with advanced solid tumors who have failed prior lines of therapy and have no clinically beneficial treatment options.
About STACT Biological Platform
Actym Therapeutics has engineered a new drug modality, STACT (Salmonella Typhimurium-Attenuated Cancer Therapy), harnessing the power of a genetically modified bacterial vehicle that safely introduces therapeutic payloads to activate the immune response in the tumor microenvironment (TME). It is a modular multi-faceted platform enabling cell-, microenvironment-, and tissue-targeted delivery of large combinatorial multiplexed payloads via safe systemic administration with engineered auxotrophy allowing for tissue-specific localization and enrichment for oncology and non-oncology indications. Expression of payloads, including therapeutic DNA, RNA, protein, peptide, and gene editing effectors, can be enabled in either the bacterial vehicle or targeted human cells. Actym’s proprietary platform enables tumor-localized expression of payloads at levels that are not tolerated systemically, and the ensuing local engagement of both innate and adaptive anti-tumor immunity.
About ACTM-838
ACTM-838 is Actym’s first clinical asset utilizing the STACT Platform to deliver immune-modulatory payloads specifically to the tumor-resident, phagocytic antigen-presenting cells (APCs) in the TME. After a rigorous process to identify optimal payloads, the locally expressed IL-15 superagonist, IL-15plex (IL-15/ IL-15Ra), and the constitutively active engineered STING (eSTING) were selected. Separately, each payload has been clinically validated to mediate anti-tumor immunity when administered locally. Combined, Actym has shown these payloads have exceptional synergistic activity in preclinical models. When expressed in the TME by ACTM-838, their complementary mechanisms result in an effective durable anti-tumor immunotherapy that can be safely administered systemically.
Engineered to be auxotrophic for adenosine metabolites, ACTM-838 localizes to the TME where it survives and proliferates in the adenosine-rich tumor milieu. It is phagocytosed by APCs and delivers IL-15-plex and eSTING transgenes to these cells that subsequently express the proteins in the local TME. Phagocytosis of the accumulated STACT chassis in the TME initiates activation of innate immunity. Local expression of eSTING further stimulates the innate immune system by triggering type I interferon (IFN) pathways and other cytokines. This switches the immunosuppressive TME from a pro-tumor Th2/M2 TME to an anti-tumor Th1/M1 and activated NK immune phenotype, priming a new T cell response. Locally expressed IL-15-plex additionally supports the activation and viability of NK and B cells as well as existing and newly primed T cells. Through this multifaceted mechanism, ACTM-838 engages both innate and adaptive immunity to generate a comprehensive, robust, and durable anti-tumor immune response in the body. The Phase 1 clinical study of ACTM-838 is designed to establish safety, payload delivery, and proof-of-mechanism of the STACTÔ biological platform and ACTM-838 in humans.