Sirnaomics announces the publication of the results of the STP705 clinical study for the treatment of isSCC in the Peer-Reviewed Journal of Drugs in Dermatology


GAITHERSBURG, Md. and SUZHOU, China, June 16, 2022 /PRNewswire/ Sirnaomics Ltd. (“Sirnaomics“, stock code: 2257.HK), a leading biopharmaceutical company in the discovery and development of RNAi therapies, announced the peer-reviewed publication of results from the Phase IIa clinical study of its lead therapeutic candidate, STP705, for the treatment of skin cancer, in the May 2022 issue of the Journal of Drugs in Dermatology (the “JDD“). The study, titled “Safety and Efficacy of TGF-β1/COX-2 Silencing Therapeutic in Adults with Cutaneous Squamous Cell Carcinoma In Situ”, showed that STP705 was safe and well tolerated in patients with squamous cell carcinoma skin in situ (isSCC) .

The main results of the publication indicate that this single-center, open-label, dose-escalation cohort study evaluated the safety and efficacy of various doses of intralesional injections of STP705, a TGF-β1/COX-2 associated therapeutic agent. to a histidine-lysine polypeptide (siRNA/HKP) silencing nanoparticles, in patients with cutaneous cell carcinoma. The primary endpoint was the proportion of patients with complete histological clearance. Twenty-five patients received STP705 of which nineteen (76%) achieved histological clearance. In the 30 µg/treatment and 60 µg/treatment groups, 80% and 100% of them achieved histological clearance, respectively. As a result of the study, STP705 appears to be non-invasive, safe and effective in the treatment of cutaneous squamous cell carcinoma in situ. The recommended doses for future study of the investigational product are 30 µg/treatment and 60 µg/treatment.

At the Clinical Dermatology Conference last fall 2021, Brian Berman, MD, PhD, Professor of Dermatology at the University of Miami Miller School of Medicine, Board Member of the American Academy of Dermatology and principal investigator of the clinical study of STP705 for the treatment of isSCC, gave a presentation on the details of the clinical development and the results of the study. Following its presentation, an audience survey was conducted of over 2,000 clinical dermatologists, with questions about whether STP705 met a clinical practice need for the treatment of isSCC. The results of the survey provided a strongly favorable opinion regarding the potential clinical application of STP705. As part of the Gore Range Capital Skin Health Innovation Competition at the conference, Sirnaomics STP705 was selected as one of the top three finalists.

“There are currently a limited number of approved non-surgical treatments for isSCC. Our results suggest that STP705 has the potential to be a viable option for patients with skin lesions due to this form of non-melanoma skin cancer, and the publication and survey results further validated the potential for clinical application of this novel siRNA therapy,” said Michael Molyneaux. MD, Executive Director and Chief Medical Officer of Sirnaomics and lead author of the study. “Overexpression of the TGF-β1 and COX-2 genes is strongly associated with the development of SCC, with TGF-β1 playing a prominent role in tumor progression. By using RNAi-based therapies such as STP705 that silence these genes, we have the potential to block isSCC proliferation by non-invasive means. This study supports this thesis, and we plan to continue to evaluate the 30 mcg and 60 mcg doses in future studies.

“The peer-reviewed publication of the results of our Phase IIa STP705 clinical study for the treatment of isSCC in JDD, together with the favorable opinion among clinical dermatologists, further strengthens our confidence in pursuing STP705 clinical studies. for applications in various types of non-melanoma skin cancers.” said Patrick Lu, Ph.D., Founder, Chairman, Executive Director, President and Chief Executive Officer of Sirnaomics. “It s It is a widespread type of cancer, with more than five million new diagnoses in the United States each year, and after surgical removal, patients may have an increased risk of tumor progression, metastasis and recurrence as well as “a risk of infection, hematoma and scarring. These patients need an alternative, non-invasive treatment option, which is why we are evaluating STP705.”

About non-melanoma skin cancer and squamous cell carcinoma in situ

Non-melanoma skin cancers (NMSCs) are the most common forms of human neoplasia. NMSCs are a large group of non-melanoma skin cancers, including squamous cell carcinoma (SCC), basal cell carcinoma (BCC), extramammary Paget’s disease (EMPD), Merkel cell carcinoma (MCC ) and cutaneous adnexal carcinomas. Of these, BCC and SCC represent the majority of NMSCs with more than 5 million new cases diagnosed in the United States each year. Squamous cell carcinoma in situ, also called Bowen’s disease, is the oldest form of SCC. Along with BCC, SCC is one of the two main subtypes of NMSC.

According to Incidence Estimate of Non-melanoma Skin Cancer (Keratinocyte Carcinomas) in the US Population, 2012, the number of new cases of isSCC in the United States was 1.3 million in 2020 and is expected to reach 3.4 million in 2030. In China, according to the Chinese Society of Clinical Oncology, the number of new cases of isSCC is 11,000 in 2020 and is expected to increase to 26,000 in 2030.

A report authorized by the World Health Organization from the “International Agency for Research on Cancer” (2019) demonstrated that the number of deaths in 2018 worldwide for men and women in NMSC is 65,155, where NMSC patient mortality in Asia accounts for 41.9% of the global total, significantly more than other individual areas.

Surgery is currently the most common treatment option for the treatment of NMSC. The different forms of surgical modalities carry significant adverse skin events, risk of scarring, infection and bleeding. Surgery can also have a significant recurrence rate. As a result, there is a high unmet need for a safe and effective U.S. Food and Drug Administration (FDA)-approved local injection therapy.

About STP705

Sirnaomics’ lead product candidate, STP705, is an siRNA (small interfering RNA) therapeutic treatment that leverages a dual-target inhibitory property and enhanced delivery by polypeptide nanoparticles (PNPs) to directly inhibit the expression of the TGF-β1 and COX-2 genes. The product candidate has received multiple IND approvals from the US FDA and Chinese National Medical Products Administration, including for the treatment of cholangiocarcinoma, non-melanoma skin cancer, and hypertrophic scarring. STP705 has also received orphan drug designation for the treatment of cholangiocarcinoma and primary sclerosing cholangitis. STP705 is currently undergoing five clinical trials for different indications: a phase IIa for isSCC, a phase II for BCC, a phase I/II for keloid scarring, a phase I/II for hypertrophic scar and a phase I for liver cancer (basket).

About Sirnaomics

Sirnaomics is an RNA therapy biopharmaceutical company with pre-clinical and clinical-stage product candidates focused on the discovery and development of innovative drugs for indications with high medical needs and large market opportunities. Sirnaomics is the first clinical-stage RNA therapy company with a strong presence in China and the United States, and also the first company to achieve positive Phase IIa clinical results in oncology for an RNAi therapy for its lead product, the STP705. Learn more at

Michael Molyneaux, MD, MBA
Executive Director and Chief Medical Officer, Sirnaomics
Email: [email protected]

Investor Relations:
Nigel Yip
Chief Financial Officer, China, Sirnaomics
Email: [email protected]

US Media Contact:
Alexis Feinberg
Tel: +1 203 939 2225
Email: [email protected]

Asia media contact:
Bunny Lee
Tel: +852 3150 6707
Email: [email protected]


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