Sirnaomics announces positive interim data from a Phase IIb clinical trial of STP705 for the treatment of squamous cell skin cancer in situ in adults

Sirnaomics Ltd.
(the "Company", "Sirnaomics", stock code: 2257.
HK.
HK), is a biopharmaceutical company
focusing on the exploration and development of RNAi therapeutics.
Sirnaomics announced on December 14 interim clinical data for the ongoing Phase IIb Phase I clinical of
STP705 for the treatment of squamous cell skin cancer in situ (isSCC).
The results of this interim data showed that of the 32 patients treated with STP705, the majority (78%) reached the primary endpoint (complete histological clearance of tumor cells).

Of the three cohorts, 89% of the optimal effect group reached the primary endpoint
.
STP705 is a siRNA (small interfering nucleic acid) therapy that utilizes dual-targeted inhibitory properties and peptide nanoparticles (PNP) to enhance delivery efficiency to directly knock down TGF-β1 and COX-2 gene expression
.

This two-phase double-blind, randomized, placebo-controlled Phase IIb clinical study was conducted to evaluate the safety and efficacy
of intralesional injection of STP705 in the treatment of isSCC at different doses.
In the first phase of this clinical trial, we have injected 32 patients with STP705 at 30 μg/ml, 60 μg/ml, and 90 μg/ml respectively, and 12 patients with 0 μg/ml placebo
.
After a six-week repeat dose, we collected treated lesion tissue samples and performed histological analysis
.

This interim report is dedicated to the results of the first part of 44 patient studies
.
According to our Phase IIb clinical study plan, the second phase of the study will include an additional 60 subjects treated with injections of STP705 or placebo at designated doses, bringing the total number of subjects to more than 100.

Selected participants will be randomized to receive weekly administration of STP705 or placebo for six weeks
.
The lesion will be removed
by the seventh week.

Dr.
Yang Lu, Founder, Chairman of the Board, Executive Director, President and Chief Executive Officer of Sirnaomics, said, "The positive clinical data from Phase I II study further confirms the suitability of our STP705 for the treatment of non-melanoma skin cancer
。 With the positive clinical results of this study and the clinical results of basal cell carcinoma of the skin (see Sirnaomics' press release issued by PR Newswire on August 29, 2022), we are more keen to focus STP705 on the therapeutic application of cutaneous squamous cell carcinoma (SCC) and skin basal cell (BCC), which can address the vast unmet medical need of novel RNAi cancer therapies
.
" ”

"In our clinical trials to date, patients who received different doses of STP705 over six weeks achieved better histological clearance of the lesion after resection of isSCC compared to patients receiving placebo
.
" Dr.
Michael Molyneaux, Executive Director and Chief Medical Officer of Sirnaomics, said, "As we move into the subsequent phases of this clinical trial, we will use these data to determine the most effective dose
of STP705 for the treatment of SCC.
SCC is a non-melanoma skin cancer that affects millions of people in the United States, and only a few non-surgical treatments for SCC are currently approved
.
”

According to the interim report of the unblinded results of the first phase of this phase IIb clinical study, 25 of the 32 subjects achieved high histological clearance (78%)
after treatment with STP705 。 Of the three treatment groups, the highest histological clearance (89%) was achieved in the 30 μg treatment group (N=9), 75% in the 60 μg treatment group (N=12), and 73% in the 90 μ g treatment group (N=11), all three groups were significantly higher than the 58% histological clearance in the placebo group (N=12
).
At the same time, there were no treatment-related adverse events (AEs) or serious adverse events (SAEs) in this clinical study, and the local skin reaction values were stable or improved
in all treatment groups.

About non-melanoma skin cancer

Non-melanoma skin cancer (NMSC) is the most common form of human tumor, and NMSC includes a variety of non-melanoma skin cancers, including squamous cell skin cancer (SCC), basal cell carcinoma (BCC), extramammary Bergard's disease (EMPD), Merck Mack's cell carcinoma (MCC), and adnexal skin tumors
.
Among them, BCC and SCC account for a relatively high proportion of NMSC, estimated to have more than 5 million new cases
in the United States each year.
BCC and SCC are the two main subcategories
of NMSC.
In the United States, the NMSC therapeutics market is expected to increase from $6.
5 billion in 2020 to $22 billion
by 2030.
In China, the market size of NMSC was $38 million in 2020 and is expected to accelerate in the coming years, increasing to $149 million
in 2030.

According to the "International Agency for Research on Cancer" report (2019) authorized by the World Health Organization, the number of deaths from NMSC in 2018 was 65,155 men, of which the mortality rate of NMSC patients in Asia accounted for 41.
9% of the global total, significantly higher than other individual regions
.

Surgery is currently the most common treatment option for NMSC, but all forms of surgery carry significant risks
of adverse skin reactions, scarring, infection, and bleeding.
For this reason, there is still a huge medical need
for safe and effective topical injection therapies approved by the US Food and Drug Administration.

About STP705

Sirnaomics' lead product candidate, STP705, is a siRNA (small interfering nucleic acid) therapy that utilizes dual-targeted inhibition properties and peptide nanoparticle (PNP) enhanced delivery to directly knock down TGF-β1 and COX-2 gene expression
.
The product candidate has received multiple IND approvals from the U.
S.
Food and Drug Administration (FDA) and the National Medical Products Administration (NMPA) of China, including for the treatment of cholangiocarcinoma, non-melanoma skin cancer, and hypertrophic scars
.
STP705 has also been granted orphan drug designation
for the treatment of cholangiocarcinoma and primary sclerosing cholangitis.
STP705 is currently in seven clinical trials for different indications: a Phase IIb clinical trial for squamous cell carcinoma in situ (isSCC), a Phase II clinical trial for the treatment of basal cell carcinoma (BCC), a Phase I/II clinical trial for the treatment of keloids, a Phase I/II clinical trial for the treatment of hypertrophic scars, a Phase I/II clinical trial for the treatment of facial isSCC, A Phase I clinical trial for the treatment of liver cancer and a Phase I clinical trial
for aesthetic medicine.