• Six cohorts, totaling 50 late-stage cancer patients, received STP707 four times monthly by intravenous infusion at escalating dosages.
• All cohorts demonstrated a strong safety profile with no dose-limiting toxicity noted for any dosing cohort and the treated patients exhibited encouraging efficacy signal with 74 % of evaluable participants achieving a best response of stable disease with a time on study of approximate 77 days.

"This is the first time in the field of RNAi cancer therapeutics that a Phase I study has demonstrated very promising clinical potential for metastasized tumors. We observed patients achieving stable disease status with some realizing a reduction in tumor size treated with STP707," said Dr. Patrick Lu, Founder, Chairman of the Board, Executive Director, President and Chief Executive Officer of Sirnaomics. "The results from this basket study encourages us to explore STP707 as a potential single drug or a combination treatment with immune check point inhibitor drugs."

The basket study enrolled 50 patients with late-stage solid tumors including but not limited to pancreatic cancer, liver cancer, colon cancer, ovarian cancer and melanoma, who all exhibited progressive disease on prior rounds of treatment with marketed oncology drugs. Based on preliminary efficacy observations, 74% of evaluable patients demonstrated a best response of stable disease (SD) and several patients exhibited reduction in tumor burden per RECIST.

The clinical study was conducted in the United States, with participation of multiple leading cancer centers, including Mayo Clinic Oncology, Yale Cancer Center, Next Oncology, Emory Cancer Center and University of Southern California/Hoag. The multi-center, open-label, dose escalation study evaluated the safety, tolerability and antitumor activity of STP707 with 50 participants receiving doses at 3 mg, 6 mg, 12 mg, 24 mg, 36 mg and 48 mg via intravenous administration. All patients were dosed once weekly for a total of four doses over a 28-day treatment cycle. The treated patients will continue in the study until they exhibit progressive disease. Additional secondary endpoints are to determine the pharmacokinetics and biomarker of STP707 and to observe preliminary anti-tumor activity. After completing the required observation period for dose limiting toxicities for the six dose cohorts, each cohort exhibited no dose-limiting toxicity and dose escalation was recommended by the data safety committee. Additional clinical data will be announced after completion of all ongoing treatment and observations.

"STP707 has exhibited a strong safety profile when compared to other novel oncology therapeutics, and we have seen encouraging efficacy signals where 74% of evaluable patients demonstrated a best response of stable disease and a number of patients exhibited reduction in tumor burden per RECIST ," said Dr. Michael Molyneaux, M.D., Executive Director and Chief Medical Officer of Sirnaomics, "It is important to emphasize that patients in this study received multiple forms of prior treatments including surgery, radiation, and tumor specific first-and second-line therapies. All patients  had failed  these prior treatment regimens, so this group of patients represent a subset of resistant tumor types. It is encouraging to see very strong safety combined with duration of response, and we look forward to continuing this study".