Teams of scientists from University of Texas Southwestern continue to reveal advances in the treatment of cancer at the American Association for Cancer Research Annual Meeting in San Diego. Yesterday, Dr. Muhammad Shaalan Beg, co-leader of the gastrointestinal oncology group at UT Southwestern’s Harold C. Simmons Cancer Center in Dallas, presented interim safety data from a multicenter, open-label Phase 1 clinical trial evaluating the use of MRX34 in patients with unresectable primary liver cancer or solid cancers with liver involvement.
MRX34 was developed by the Austin-based biopharmaceutical company Mirna Therapeutics. Mirna focuses on the development and commercialization of microRNA-based therapeutics and was the first company to launch a clinical trial of any miRNA mimic drug for the treatment of cancer in 2013. Specifically, MRX34 is a double-stranded miRNA mimic of miR-34, a naturally occurring tumor suppressor that inhibits cell cycle progression and induces cancer cell death.
During the trial, approximately 30 patients were used to identify a recommended Phase 2 dose of MRX34, which was delivered to patients intravenously twice a week for three weeks with one week off in 28-day cycles. This primary outcome was accompanied by the secondary objective of assessing safety, tolerability, clinical activity, and pharmacokinetic profiles of MRX34. Three centers in Texas (UT Southwestern Medical Center, MD Anderson Cancer Center, and University of Texas Health Science Center San Antonio/Cancer Therapy & Research Center) and two centers in Arizona are currently recruiting patients to continue the study.
At the present, MRX34 shows a manageable safety profile with only one incident of dose-limiting toxicity. Adverse events consisted of fever, chills, fatigue, thrombocytopenia, diarrhea, back and flank pain, nausea, and neutropenia following infusion of MRX34. Paul Lammers, MD, president and chief executive officer of Mirna, stated, “We are pleased with the support Mirna has received from the participating oncology research centers, the speed of patient enrollment and the manageable safety profile observed to date with MRX34, the first microRNA mimic in clinical trials.” The trial is jointly funded by the Cancer Prevention Research Institute of Texas.