Marina platform to deliver first-ever miRNA cancer drug for Mirna PhI

Texas biotech Mirna Therapeutics began a Phase I clinical trial of its miRNA cancer drug MRX34 with a liposomal delivery platform the company licensed from Marina Biotech ($MRNA). It is the first cancer-targeting miRNA drug to advance to the clinic.

The miRNA, or microRNA, drug MRX34 is a "mimic" of the natural tumor suppressor miR-34, which acts upon genes in the body to control the spread of cancer. By replacing miR-34, the new drug is designed to regulate the "occurrence, growth and dissemination of many cancers," according to the company.

Getting the miRNA to the nuclear material, though, has been a major hurdle in the development of these drugs in the past. Thus, Marina's "Smarticles" liposomal delivery technology, which it bought from Novosom in 2010 for $5 million, will play an important role in the success of the drug. The liposomes are pH-dependent, charge-transitioning particles that are designed to release a nucleic acid--in this case MRX34--within the nucleus. Without the liposomal capsule, miRNA will lose much of its structure, which is crucial to its performance.

Funded in part by a Cancer Prevention and Research Institute of Texas Commercialization grant, Mirna will conduct the standard oncology study with an initial dose-escalation phase and an enrichment phase with an expected enrollment of up to 48 patients.

"The initiation of this clinical trial is a landmark event for cancer drug development," said Mirna President and CEO Paul Lammers in a statement. "Scientists at Mirna were among the first to elucidate the promise of tumor suppressor miRNAs as new therapeutic candidates. The preclinical profile of MRX34 across a range of tumors strongly suggests that miRNA-based therapeutics may represent a potent, new class of anticancer drugs working through a mechanism that affects multiple oncogenic pathways simultaneously."

And Marina Executive Vice President of R&D Richard Ho said in a statement: "With the initiation of this trial, Marina will be the only company with a delivery technology that is being used to deliver both single-stranded and double-stranded oligonucleotide therapeutics in clinical trials. We look forward to Mirna's continued advancement of this program and the validation of our oligonucleotide delivery platform."

- here's Mirna's release
- and here's Marina's release