Mirna Therapeutics Taking on Cancer With Help of Tiny RNAs

Xconomy Texas — 

Mirna Therapeutics, an Austin-based life sciences startup, is bringing out the big guns in the fight against cancer, in the form of tiny RNA molecules.

In just over three years, Mirna has raised nearly $50 million to develop drugs based on microRNAs, very short strands of RNA that can act like genomic master switches, each turning off multiple genes at the same time. The startup is in the middle of its first clinical trial, testing one such drug’s ability to treat primary liver cancer or metastatic cancer that has spread to the liver. About 20,000 people died from the disease in the United States in 2010, according to National Cancer Institute.

Mirna is currently conducting a phase 1 clinical trial with six patients at the Cancer Therapy & Research Center at the Health Science Center at the University of Texas at San Antonio. The trial will continue throughout this year and 2014 with a total of 48 patients in San Antonio, the University of Texas Southwestern Medical School in Dallas, the Mayo Clinic in Phoenix, and Virginia G. Piper Cancer Center at Scarsdale Health in Arizona.

Mirna CEO Paul Lammers (pictured,) a Dutch physician and biologist, says the 19-person-strong startup hopes to use results from the phase 1 trial to home in on a specific cancer to target in its next study. It aims to conduct that phase 2 trial in early 2015.

The biggest challenges for the company have been in identifying microRNAs that can affect cancer-causing genes (it has found 20 to date) and coming up with an effective method to deliver drugs based on those molecules, Lammers says. MicroRNAs can degrade in the blood stream so Mirna developed an IV drug that protects them in so-called liposomes, tiny bubbles made out of the same material as a cell membrane, something that “livers are very eager to pick up,” he explains.

“It’s distributed throughout the body and it’s then brought to the tumor,” Lammers added. “The blood vessels are leaky in cancer and the liposomes escape into the tumor because of the leaky vessels.”

The company’s approach has attracted investors even in a difficult fundraising environment for life sciences startups. Mirna spun out from the Austin biotech firm Asuragen in 2009 with a Series A round of $5 million from its parent company to pay for its first two years of operating expenses. In 2009, the startup received a $5 million grant from the Texas Emerging Technology Fund and it then received a 3-year, $10.3 million grant from the Cancer Prevention and Research Institute of Texas. In October of last year, it closed on $34 million in financing from venture capital firms.

For his part Lammers, a 20-year veteran of the pharmaceutical industry who joined Mirna in November 2009, is plainly excited about the possibilities of microRNAs. The molecules’ power lies in the fact that each is “a single entity that affects so many genes at the same time, especially those that have gone astray in cancer,” he says. “This is a great new paradigm and treatment opportunity for cancer.”