Sirnaomics Accelerates Clinical Development of STP705 for the Treatment of Non-Melanoma Skin Cancers

HONG KONG, GERMANTOWN, Md., and SUZHOU, China, Feb. 1, 2023 /PRNewswire/ -- Sirnaomics Ltd. (the "Company" or "Sirnaomics", stock code: 2257.HK), a leading biopharmaceutical company in discovery and development of RNAi therapeutics, today announced that it is advancing the clinical development of STP705 for the treatment of two non-melanoma skin cancers: Squamous Cell Carcinoma in situ (isSCC) and Basal Cell Carcinoma (BCC). Based on positive clinical readouts from a Phase IIb study for isSCC and a Phase II study for BCC, Sirnaomics is formulating a communication package for the U.S. Food and Drug Administration (FDA) to seek guidance for conducting a late-stage clinical development for the treatment of isSCC and BCC. Additionally, the Company has developed a commercialization plan to position STP705 when upcoming clinical studies reach primary endpoints.

An interim report in December 2022 in respect of the Phase IIb study of STP705 for the treatment of isSCC showed that the majority (78%) of the 32 patients treated with STP705 achieved histological clearance, the primary endpoint of the study. One out of the three treatment cohorts achieved 89% histological clearance. The positive results further validated STP705 as a novel siRNA (small interfering RNA) therapeutic, taking advantage of a dual-targeted inhibitory property and a polypeptide nanoparticle (PNP)-enhanced delivery to directly knock down both TGF-β1 and COX-2 gene expressions.

In August 2022, the Company reported that the Phase II clinical study of STP705 in five patients with BCC showed an optimal clinical dosage of 180µg and achieved a 100% histological clearance and completed response (CR), indicating the potential viability of the treatment. Apart from achieving a 100% CR, the data in this cohort showed improved or stable cosmetic results with an excellent safety profile and no significant cutaneous skin reactions. The success of BCC treatment with STP705 further validated the potential for the treatment of non-melanoma conditions.

"In our clinical studies for STP705 to date, we have achieved significant efficacy and a strong safety profile," said Dr. Michael Molyneaux, M.D., Executive Director and Chief Medical Officer of Sirnaomics. "As we continue to study this promising therapeutic candidate, we will further confirm the most effective dose and the therapeutic benefits for the treatment of isSCC, SCC and BCC. Those non-melanoma skin cancers are affecting millions of people in the United States and globally. Currently, there are only a small number of approved non-surgical treatments. We have formulated a marketing and launch strategy for using our injectable treatment approach to compensate the shortcoming of the surgical treatment."

"The latest results from the Phase IIb study of isSCC and Phase II study of BCC has shown efficacy of STP705 without any drug related Adverse Events (AEs) and Serious Adverse Events (SAEs), validating the broad potential of STP705 for treatment of non-melanoma skin cancers," said, Dr. Patrick Lu, Founder, Chairman of the Board, Executive Director, President and CEO of Sirnaomics. "With guidance from the FDA, Sirnaomics is confident to move our lead drug candidate into later-stage clinical development to further explore and evaluate the great potential of STP705 for the treatment of non-melanoma skin cancers."

About Non-Melanoma Skin Cancers

Non-melanoma skin cancers (NMSC) are the most common forms of human neoplasia. NMSC constitute a large group of skin cancers that are not melanoma, including squamous cell carcinoma (SCC), basal cell carcinoma (BCC), Extramammary Paget's Disease (EMPD), Merkel cell carcinoma (MCC), and skin adnexal carcinomas. Among these, BCC and SCC account for the majority of NMSC with an estimate of more than 5 million newly diagnosed cases in the United States every year. Along with BCC, SCC is one of two major subtypes of NMSC. The market size of the NMSC treatment market in the United States is expected to increase from US$6.5 billion in 2020 to US$22 billion in 2030. In China, the market size of NMSC treatment was US$38 million in 2020 and is also expected to grow rapidly in the coming years, reaching US$149 million in 2030.

A World Health Organization authorized report from the "International Agency for Research on Cancer" (2019) revealed that the number of deaths in 2018 globally for both men and women from NMSC is 65,155, of which 41.9% were within the populations of Asians, which is significantly more than other populations.

Surgery is currently the most common treatment option for the treatment of NMSC. The various forms of surgical modalities carry significant cutaneous adverse events, risk of scar, infection and bleeding. As a result, there is a high unmet need for an FDA-approved local injection therapy that is safe and effective.

About Sirnaomics

Sirnaomics is an RNA therapeutics biopharmaceutical company with product candidates in preclinical and clinical stages that focuses on the discovery and development of innovative drugs for indications with medical needs and large market opportunities. Sirnaomics is the first clinical-stage RNA therapeutics company to have a strong presence in both China and the United States, and also the first company to achieve positive Phase IIa clinical outcomes in oncology for an RNAi therapeutic as its core product, STP705. Learn more at

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SOURCE Sirnaomics Ltd.

Company Codes: HongKong:2257

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