Sirnaomics Doses the First Patient in Phase I/II Clinical Study of RNAi Therapeutic STP705 for Treatment of Facial Squamous Cell Skin Cancer In Situ

Data results will be available in Q1 2023

GAITHERSBURG,Md. and SUZHOU,China,Aug. 18,2022 -- Sirnaomics Ltd.(the "Company" or "Sirnaomics",stock code: 2257.HK),a leading biopharmaceutical company in discovery and development of RNAi therapeutics,announced today that the Company has dosed the first patient in a Phase I/II clinical study of STP705,the Company's leading siRNA (small interfering RNA) drug candidate,for the treatment of patients with facial squamous cell skin cancer in situ (isSCC).

The open label,dose escalation study is designed to evaluate the safety,tolerability,and efficacy of various doses of STP705 administered by intralesional injection and to determine the recommended dose. The study will also analyze biomarkers common to isSCC formation pathways,including TGF-β1 and COX-2. The primary endpoint is to determine the number of patients with histological clearance (HC) of facial isSCC lesions at the end of treatment with STP705. HC is defined as the absence of detectable evidence of the isSCC tumor cell nests as determined by central pathology review. A total of 30 patients,divided into three cohorts of 10 patients each,will receive a given dose once per week for six weeks. Cohort A will receive a 30 μg dose,Cohort B a 60 μg dose,and Cohort C a 90 μg dose.

"We expect that the study of STP705 as a treatment for facial isSCC to yield positive results given previous studies of STP705 that have shown to be safe and effective as a cancer treatment," said Dr. Patrick Lu,founder,Chairman of the Board,Executive Director,President and CEO of Sirnaomics. "Our drug has the potential to offer millions of patients with these non-melanoma facial lesions a non-surgical,non-invasive alternative to traditional lesion removal."

"With surgical removal being the only available treatment for isSCC currently,patients have normally found the results to be painful and aesthetically unpleasing on the face. By dosing our first patient in this Phase I/II study,we can begin to evaluate the safety and effectiveness of STP705 in eradicating these cancerous lesions," said Michael Molyneaux M.D.,Executive Director and Chief Medical Officer of Sirnaomics. "Formulating this clinical trial as a dose escalation study also gives us the opportunity to determine which dose is the best suited in removing the cancer without adverse events."

The study started in the United States in August 2022,and is expected to be completed in Q1 2023. Additional information about this clinical trial is available at clinicaltrials.gov using the identifier: NCT05421013.

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 COX2 gene expression. The product candidate has received multiple IND approvals from both the U.S. Food and Drug Administration (FDA) and the Chinese National Medical Products Administration (NMPA),including treatments of cholangiocarcinoma,non-melanoma skin cancer and hypertrophic scar. STP705 has also received Orphan Drug Designation for treatment of cholangiocarcinoma (CCA) and primary sclerosing cholangitis (PSC). STP705 is currently in seven clinical trials for different indications: a Phase IIb for squamous cell carcinoma in situ (isSCC),a Phase II for basal cell carcinoma (BCC),a Phase I/II for keloid scarring,a Phase I/II for hypertrophic scar (HTS),a Phase I/II for facial isSCC,a Phase I for liver cancer (basket),and a Phase I for medical cosmetology treatment.

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 for its core product,STP705. Learn more at www.sirnaomics.com.

CONTACT:

Michael Molyneaux,MD,MBA

Executive Director and Chief Medical Officer,Sirnaomics

Email: MichaelMolyneaux@sirnaomics.com

Investor Relations:

Nigel Yip

Chief Financial Officer,Sirnaomics

Email: NigelYip@sirnaomics.com

US Media Contact:

Alexis Feinberg

Tel: +1 203 939 2225

Email: Alexis.Feinberg@westwicke.com

Asia Media Contact:

Bunny Lee

Tel: +852 3150 6707

Email: sirnaomics.hk@pordahavas.com

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