Sirnaomics has dosed the first healthy subject in a Phase I clinical trial analysing the potential of STP707 to treat liver fibrosis in primary sclerosing cholangitis in the US.
A systemic small interfering ribonucleic acid (siRNA) therapy STP707 comprises two siRNA oligonucleotides that act on TGF-β1 and COX-2 mRNA, respectively.
It is formulated in nanoparticles with a Histidine-Lysine Co-Polymer (HKP+H) peptide as the carrier.
The randomised, single-centre, dose-escalation, sequential cohort trial will assess the safety, tolerability and pharmacokinetics of intravenous (IV) single ascending dose of STP707 in healthy subjects.
It will enrol up to 50 healthy participants of the age 18 to 55 years.
These subjects will be categorised into four cohorts to receive 3, 6, 12 or 24mg dose of the therapy.
Sirnaomics executive director and chief medical officer Michael Molyneaux said: “This Phase I study is a crucial step forward in our liver fibrosis drug development programme and will allow us to gather very important data on safety and dosing that will support our future studies utilising STP707 for the treatment of liver fibrosis due to primary sclerosing cholangitis.
“This study will allow us to expand our understanding of how this therapeutic candidate can impact more patients with rare disorders that are in need of effective treatments.”
An IV dose of STP707 was demonstrated to knock-down TGF-β1 and COX-2 gene expressions in several organs including liver and lung, in preclinical studies.
Furthermore, it showed antitumor activity against several solid tumour types in preclinical models.
In February this year, the company reported interim findings from a Phase II trial of STP705 to treat cutaneous basal cell carcinoma (BCC).
Results showed that trial subjects had dose-response with a complete response following the administration of the siRNA therapeutic.
In addition, the participants had enhanced or stable cosmetic results without any substantial cutaneous skin reactions.
Sirnaomics dosed the first subject in US Phase I trial of STP705 to treat liver cancer, in June last year.