miRagen Therapeutics, Inc. (NASDAQ: MGEN), a clinical-stage biopharmaceutical company focused on the discovery and development of RNA-targeted therapies, today announced data from its Phase 1 clinical trial evaluating the safety, tolerability, pharmacokinetics (PK), pharmacodynamics (PD) and efficacy of cobomarsen, an inhibitor of miR-155, in mycosis fungoides (MF) patients. These data will be presented today in a poster session at the 60th American Society of Hematology (ASH) Annual Meeting, which is being held in San Diego, CA, from December 1st – 4th.
“We are excited to present final data from our Phase 1 cobomarsen clinical trial, which continue to show that cobomarsen is safe and well-tolerated, has relevant biological and clinical activity in patients and has the potential to impact the quality of life for MF patients,” stated miRagen Executive Vice President, R&D, Paul Rubin. “We believe the Phase 1 data has provided us with the means and the confidence to design and implement a larger controlled trial in MF patients.”
The Phase 1 clinical trial investigated the safety, tolerability, PK, PD and efficacy of cobomarsen in a total of 43 MF patients. Cobomarsen was initially administered via intratumoral injection (75 mg/dose), and then via systemic administration by subcutaneous (SC), intravenous (IV) bolus or IV infusion, at 300, 600 or 900 mg/dose with loading doses in the first week followed by weekly maintenance dosing. The patients had been in the clinical trial for up to 23 months as of the reporting of these data. Highlights from the trial observations include:
92% of the MF subjects in the systemic administration cohorts had improvement in tumor burden as assessed by modified Severity Weighted Assessment Tool (mSWAT) score independent of concomitant therapies
52% of patients receiving more than six doses achieved a partial response (at least a 50% reduction) in mSWAT score; with 69% of these patients who achieved a partial response maintained the response for at least four consecutive months (ORR4 based on mSWAT). For these patients, the mean duration of response was 259 days at the time of the data cutoff.
Cobomarsen was generally well-tolerated at all doses tested.
“We are pleased with the results from the Phase 1 clinical trial for cobomarsen. Importantly, we also observed an improvement in quality of life that correlated with reductions in tumor burden as assessed by mSWAT score during the treatment phase,” said William S. Marshall, Ph.D., President and Chief Executive Officer of miRagen Therapeutics. “The data from the Phase 1 clinical trial drove our decision to advance the investigation of cobomarsen in the Phase 2 SOLAR clinical trial for patients with MF. Based on our discussions with the U.S. Food and Drug Administration, we believe the results generated in the SOLAR trial could allow us to seek accelerated approval for cobomarsen in the United States.”