Sirnaomics Initiates Phase I Clinical Trial of RNAi Therapeutic STP707 for Systemic Treatment of Solid Tumors

HONG KONG, Feb. 9, 2022 /PRNewswire/ --China SuState Biomedical Industrial Park - Sirnaomics Ltd. ("Sirnaomics", Stock Code: 2257.HK) is a leading biopharmaceutical company specializing in the exploration and development of RNAi therapeutics. Sirnaomics today announced that a Phase I clinical trial has been initiated in the United States to evaluate the efficacy of the small interfering ribonucleic acid (siRNA) candidate drug STP707 administered intravenously for the treatment of various solid tumors. Two patients have already received treatment.

This multicenter, double-blind, dose-escalation and dose-expansion Phase I clinical trial will evaluate the safety, tolerability, and anti-tumor activity of STP707 administered intravenously. Thirty subjects with advanced solid tumors who are unresponsive to standard therapies will initially participate in the dose-escalation testing. Once the maximum tolerated dose or recommended Phase II dose is determined, an additional ten subjects will be recruited to further study and confirm the safety and anti-tumor activity of STP707. This study will include five cohorts of patients, each receiving one of five dose levels of STP707 via intravenous infusion in 28-day cycles. The primary endpoint is to determine the maximum tolerated dose and provide a dose recommendation for future Phase II clinical studies. Secondary endpoints include assessing the pharmacokinetics of STP707 and observing preliminary anti-tumor activity.

Dr. Yang Lu, Founder, Chairman of the Board, Executive Director, President and Chief Executive Officer of Sirnaomics, stated: "Sirnaomics has been relentlessly advancing the research and development of novel RNA interference drugs. The first intravenous administration of STP707 for the treatment of hepatocellular carcinoma and other types of solid tumors marks a significant milestone in the group's years of drug development efforts. This candidate drug has demonstrated good efficacy and safety in our preclinical studies. Our goal is to optimize siRNA drug formulations using our globally unique peptide nanoparticle delivery system (PNP) to address unmet clinical needs, particularly in the fields of oncology and fibrotic diseases. We are committed to leading the RNA interference drug industry in developing new cancer therapies, and the initiation of this clinical trial significantly advances the group's progress towards that goal."

Dr. Michael Molyneaux, Executive Director and Chief Medical Officer of Sirnaomics, stated: "Sirnaomics' mission is to develop drug candidates using RNAi therapy, including STP707, which addresses critical needs for various cancer patients. With the initiation of this Phase I clinical trial, we can expand the therapeutic scope of our drug candidate through intravenous administration. This provides us with more opportunities to explore the effects of STP707, including the dose range and anti-tumor activity validated in previous studies."

STP707 leverages dual-targeting inhibition properties and Sirnaomics' proprietary PNP delivery technology to enhance the targeted delivery of drugs to solid tumors and metastatic cancers through systemic administration. A preliminary preclinical study demonstrated that simultaneously knocking down the expression of TGF-β1 and COX-2 in the tumor microenvironment enhances T cell infiltration. Another combination therapy study showed that in a mouse orthotopic liver cancer model, the combination of STP707 and a PD-L1 antibody exhibited synergistic anti-tumor activity.

For more information about Sirnaomics clinical trials, please visitClinicalTrials.gov(Identifier NCT05037149) or company websitewww.sirnaomics.com。

AboutSTP707

STP707 consists of two siRNA oligonucleotides targeting TGF-β1 and COX-2 mRNA, formulated into a nanoparticle preparation in combination with a histidine-lysine copolymer (HKP+H) carrier. This specific peptide carrier differs from the one used in STP705. Each individual siRNA has the ability to inhibit the expression of the corresponding target mRNA. STP707 can simultaneously suppress the expression of TGF-β1 and COX-2, thereby generating a synergistic effect to reduce inflammatory responses. The overexpression of TGF-β1 and COX-2 has been demonstrated to play a critical regulatory role in tumorigenesis. In a preclinical study of STP707, intravenous administration resulted in the knockdown of TGF-β1 and COX-2 gene expression in organs such as the liver and lungs. Furthermore, STP707 exhibited antitumor activity against various solid tumor types across multiple preclinical models.

AboutSirnaomics

Sirnaomics is an RNA therapeutics biopharmaceutical company with its candidate products in preclinical and clinical stages, focusing on exploring and developing innovative drugs for the treatment of indications with unmet medical needs and significant market opportunities. Sirnaomics is the first clinical-stage RNA therapeutics biopharmaceutical company to hold a substantial market position in both China and the United States, and it is also the first company to achieve positive Phase IIa clinical results for its core product STP705, an RNAi therapy in the field of oncology. For more information about the company, please visit:www.sirnaomics.com。