Sirnaomics Announces Acceptance of Investigational New Drug Application by China NMPA for Global Multicenter Phase Ⅱb Trial of STP705 Treatment for Skin Squamous Cell Carcinoma



Sirnaomics, Inc., a biopharmaceutical company engaged in the discovery and development of RNAi therapeutics against cancer, fibrotic diseases and other unmet clinical indications, today announced that the China National Medical Product Administration (NMPA) has accepted its Investigational New Drug (IND) application for the company’s lead drug candidate, STP705, for the treatment of skin squamous cell carcinoma in situ (isSCC).


The randomized, double-blind, and placebo-controlled study, as part of a global multicenter clinical Phase 2b program, will evaluate the safety and efficacy of an intralesional injection of STP705 in 100 adult patients with isSCC in five to seven clinical sites in the U.S. and China. This is a two-part dose escalation trial with the first part (the run-in period) further evaluating the 30 ug and 60 ug dosing regimens from the Phase 2a study of STP705 in addition to a third new dose level. The second part of the trial is designed to evaluate the two most efficacious dosing regimens. The primary endpoint of this trial is the proportion of participants with histological clearance of treated isSCC lesions at the end of treatment. Histological clearance will be defined as the absence of detectable evidence of isSCC tumor cell nests as determined by central pathology review.  The study protocol for this China IND filing is following an initial protocol submitted to U.S. FDA earlier this year.



“After the conclusion of a Phase 2a clinical trial of STP705 for the successful treatment of squamous cell carcinoma in situ, with a high rate of patients achieving histological clearance in a dose dependent manner, we have already started a Phase 2b study with a green light from the U.S. Food and Drug Administration. This China IND filing reflects Sirnaomics’ long-term strategy to advance novel siRNA therapeutics in a synchronized schedule in both the U.S. and China,” said Patrick Lu, Ph.D., the founder, President and CEO of Sirnaomics. “In this first global multicenter 2b study of STP705, we will not only obtain clinical study readouts covering broader patient population with different ethnic backgrounds, but also gain experience in conducting such trials that potentially offer significant insight into addressing a great unmet medical need in these two large markets.”



“Sirnaomics is excited to start our clinical programs in China as it aligns with our mission of codeveloping drugs in the two largest markets in the world. By leveraging our strong presence in both China and the U.S., we anticipate this will aide in recruitment of patients to our studies and potentially benefit our development timelines,” said Michael Molyneaux M.D., Chief Medical Officer of Sirnaomics. “isSCC continues to be a disease with a high unmet therapeutic need for non-surgical treatment alternatives that can avoid scarring and achieve high clearance rates. We hope to build on the success seen in the Phase 2a study, where we achieved 90% histological clearance rates in the 30 ug and 60 ug dosing groups and achieved an improved appearance of the skin, as demonstrated by objective scoring scales such as the Cutaneous Response Scores. We anticipate that using a similar clinical design for our Phase 2b clinical study in China will enable us to learn more about STP705’s safety and efficacy profile with a much broader patient population.”





About Non-melanoma Skin Cancer and Squamous Cell Carcinoma In Situ 

Skin cancer is the most common type of all cancers diagnosed each year in the United States. It is estimated that nearly half of cancers diagnosed every year will be skin cancers. Over the past decade, the incidence of skin cancers has increased dramatically. According to the JAMA Dermatology paper (Rogers, et. al. JAMA Dermatol. 2015151(10):1081-1086), an estimated 3.3 million people in the US suffer from non-melanoma skin cancer (NMSC) along with 5.43 million people that are currently living with cancer lesions. Data on specific types of NMSC were 2.55 million cases for basal cell carcinoma (47%): 2.57 million cases for squamous cell carcinoma including squamous cell carcinoma in situ (46.7%), plus another 332,000 cases of unspecified type of skin cancers.


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


Squamous cell carcinoma in situ, also called Bowen disease, is the earliest form of squamous cell skin cancer (SCC). Along with basal cell carcinoma, SCC is one of two major subtypes of NMSC. The key driver for development of SCC is ultraviolet rays from the sun. It is believed that development of SCC is linked closely to genomic perturbations, genetic mutations, and altered expression of key molecules (e.g., overexpression of TGF-β1 and COX-2) that impacts squamous cell lineage commitment and terminal differentiation.


Surgery is the 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. Surgery can also have a significant recurrence rate. As a result, there is a high unmet need for an FDA approved local injection therapy that is safe and effective.




About STP705

Sirnaomics’ leading product candidate, STP705, is a siRNA (small interfering RNA) therapeutic that takes advantage of a dual-targeted inhibitory property and polypeptide nanoparticle (PNP)-enhanced delivery to directly knock down both TGF-β1 and COX-2 gene expression. The product candidate has received multiple IND approvals from both the US FDA and Chinese NMPA, including treatments of cholangiocarcinoma, nonmelanoma skin cancer and hypertrophic scar. STP705 has also received Orphan Drug Designation for treatment of cholangiocarcinoma and primary sclerosing cholangitis. A Phase 2a study of STP705 for treatment of squamous cell skin cancer (isSCC) in adult patients demonstrated positive efficacy and safety results, with 76% of all patients (19/25) achieving complete histologically clearance and the two optimal dosing ranges achieving 90% (9/10) histological clearance of tumor cell in the lesion. No significant or serious adverse events, including no significant cutaneous skin reactions, were reported in the study, and the company was able to define a clear therapeutic window in advance of later stage studies.




Read the original news release




About Sirnaomics, Inc.

Sirnaomics, Inc., a leading privately held biopharmaceutical company for discovery and development of RNAi therapeutics, is a Delaware corporation headquartered in Gaithersburg, Maryland, USA, with subsidiaries in Suzhou and Guangzhou, China. The Company’s mission is to develop novel therapeutics to alleviate human suffering and advance patient care in areas of high unmet medical need. The guiding principles of the company are: Innovation, Global Vision with a Patient Centered focus. Members of the senior management team have a great deal of combined experience in the biopharmaceutical industry, financial, clinical and business management in both the USA and China. The company is supported by funding from institutional investors and corporate partnerships. Sirnaomics has developed a strong portfolio of intellectual property with an enriched product pipeline. The therapeutic areas of focus include oncology and anti-fibrotic therapeutics. Learn more at