Sirnaomics Announces Positive Interim Phase II Clinical Data of STP705 for Basal Cell Carcinoma

HONG KONG, Feb 23, 2022 /PRNewswire/ -- Sirnaomics Ltd. ("Company”，“Sirnaomics", Stock Code: 2257.HK), is a leading biopharmaceutical company focused on exploring and developing RNAi therapies. Sirnaomics announced the interim Phase II clinical data of its siRNA (small interfering RNA) therapy, STP705, for the treatment of basal cell carcinoma (BCC) of the skin. The interim data from three groups (15 subjects in total) demonstrated complete clearance efficacy along with improved or stable cosmetic outcomes, without significant skin adverse reactions. The interim data also showed no drug-related adverse events (AEs) or serious adverse events (SAEs), indicating that STP705 has good safety as a topical treatment for skin cancer.

This open-label, dose-escalation Phase II clinical trial primarily aims to evaluate the safety, tolerability, and efficacy of different doses of STP705 administered via local injection in patients with basal cell carcinoma (BCC) of the skin. The primary endpoint is the proportion of patients achieving complete histological clearance of tumor cells within the site of the BCC lesion, defined as the absence of observable BCC tumor cell nests. Secondary endpoints include assessing the safety and efficacy of STP705 at the optimal dose and analyzing common biomarkers involved in the formation of basal cell carcinoma, including TGF-β1 and COX-2.

The interim data comprises three dose-escalation cohorts, ranging from 30 micrograms to 90 micrograms. Each cohort consists of five subjects, with a total of 15 subjects currently enrolled in the trial. Subjects receive weekly injections of STP705 for six consecutive weeks. In cohorts B and C, which receive 60 micrograms and 90 micrograms of STP705 respectively, three out of five subjects achieved complete clearance. In cohort A, receiving 30 micrograms of STP705, one out of five subjects achieved complete clearance.

Dr. Yang Lu, Founder, Chairman of the Board, Executive Director, President and CEO of Sirnaomics, stated: "The interim data from this study indicate that STP705 has achieved positive results in treating Basal Cell Carcinoma (BCC) patients, building on its already demonstrated success in treating Squamous Cell Carcinoma (SCC). This further underscores our leadership in developing RNAi therapeutics for skin cancer. We look forward to the readout of data from the remaining cohorts in this Phase II trial as we advance this key therapeutic candidate, which will enhance our understanding of STP705’s efficacy."

Sirnaomics Executive Director and Chief Medical Officer Michael Molyneaux, M.D., added, "The interim Phase II clinical data of STP705 is encouraging, demonstrating that we are on the right path to providing more treatment options for patients with basal cell carcinoma of the skin. This could serve as an alternative to surgical excision of these lesions. There remains a significant unmet medical need for non-surgical treatments for various types of non-melanoma skin cancers, and in this study, we have already observed that this non-surgical approach can achieve both reduced scarring and high tissue clearance rates."

The remaining part of this Phase II trial includes two additional groups (five subjects each) receiving 120 micrograms and 180 micrograms, respectively, with a total of 25 subjects participating in the entire clinical trial. For more information about this clinical trial, please visit:clinicaltrials.gov, Identifier: NCT04669808

About Basal Cell Carcinoma

Basal Cell Carcinoma (BCC) is a type of non-melanoma skin cancer (NMSC) associated with ultraviolet radiation from sunlight. Basal cell carcinoma rarely spreads to other parts of the body, so most cases are pre-metastatic. According to the CIC report, the metastasis rate of basal cell carcinoma ranges between 0.0029% and 0.55%, with common metastatic sites being regional lymph nodes, lungs, bones, skin, and liver. Common treatments for basal cell carcinoma include conventional surgery, Mohs micrographic surgery, topical ointments, cryotherapy, laser therapy, electrosection, and radiation therapy. Various forms of surgery can lead to significant skin adverse events, such as scarring, infection, and bleeding. Currently, only two drugs have been approved by the U.S. Food and Drug Administration (FDA) for patients with pre-metastatic basal cell carcinoma, but they may still cause skin reactions in patients.

Currently, STP705 is being applied in the treatment of basal cell carcinoma of the skin, demonstrating advantages for cosmetic appearance, particularly effective for patients with lesions on the head, face, or neck. Clinical results indicate that, compared to currently available topical therapies, STP705 achieves complete clearance more effectively.

AboutSTP705

Sirnaomics' core candidate drug, STP705, is a TGF-β1/COX-2 dual-target inhibitor based on small interfering nucleic acids. TGF-β1 and COX-2 are well-validated gatekeeper targets in the development of oncology and fibrotic disease drugs. TGF-β1 regulates a wide range of cellular processes, including cell proliferation, differentiation, apoptosis, extracellular matrix production, angiogenesis, inflammation, and immune response, while COX-2 is a mediator that promotes inflammation and proliferation. By leveraging its dual-targeting inhibition properties and an optimized polypeptide nanoparticle (PNP) delivery system, STP705 employs localized administration therapy to directly inhibit the expression of TGF-β1 and COX-2 genes in tumor lesions. The candidate drug is intended for the treatment of non-melanoma skin cancers, including in situ squamous cell carcinoma (isSCC), basal cell carcinoma (BCC), skin fibrosis, and solid liver tumors.

AboutSirnaomics

Sirnaomics is an RNA therapeutics biopharmaceutical company with 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 strong 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。

Contact Information:
Michael Molyneaux, MD, MBA 
Executive Director and Chief Medical Officer of Sirnaomics
Email:MichaelMolyneaux@sirnaomics.com

Investor Inquiry:
Ye Yongji
Sirnaomics Chief Financial Officer, China
Email:NigelYip@sirnaomics.com

U.S. Media Inquiry:
Mark Corbae
Phone: +1 203 682 8288
Email:Mark.Corbae@westwicke.com 

Asia Media Inquiry:
Li Yaorong
Phone: +852 3150 6707
Email:sirnaomics.hk@pordahavas.com