Mirna Therapeutics, an Austin-based drug development company, said last night that it had to abruptly close its Phase 1 study for its lead cancer drug because of "severe adverse events" associated with patients who were given the drug.
"The company voluntarily halted enrollment and dosing in the clinical study following multiple immune-related severe adverse events observed in patients dosed with MRX34 over the course of the trial," Mirna Therapeutics said in a U.S. Securities and Exchange Commission filing.
This is certainly bad news for Mirna, because MRX34 is its lead drug, which means Mirna believes it has the best chance for regulatory approval.
The company specializes in developing synthetic drugs that mimic microRNA, which plays a crucial regulatory role in cells.
In Mirna's Phase 1 clinical trial, the drug was being used on patients with liver cancer and lymphomas and leukemias.
In an interview with the American-Statesman, CEO Paul Lammers said the decision to shut down the trial was a "tough one" for a public company, but that ultimately it was the right call for the health and safety of the trial participants.
The decision came after one patient experienced respiratory failure after taking the drug and had an overall bad immune response.
Mirna's share price plummeted more than 20 percent Wednesday morning, hovering just under $2 a share. This is a new low for the company's share price, which started off at $7 a share when the company went public last year.
Mirna said it will also not be initiating a planned study of MRX34 in melanoma patients, which was supposed to start this year.
"The company will be further analyzing its full preclinical and clinical data set, and will discuss with its advisors, as well as the U.S. Food and Drug Administration, possible future development of MRX34," the company said in a statement.
This drug mimics the naturally occurring microRNA tumor suppressor miR-34, which is "expressed in a wide variety of cancers," the company says on its website. Mirna entered clinical trial testing in 2013.
Lammers said that the company is ending any trials associated with MRX34 has no plans at this time to pursue further development of this drug. But he stressed that the company does plan to continue research and development for other synthetic microRNA-based drugs.
He noted they have $72 million in the bank, which is a "long runway" that is expected to keep the company afloat until at least 2018.
Unfavorable clinical trial results or a rejection from drug regulators, such as the U.S. Food and Drug Administration, can cripple a drug development company.
For instance, in 2008, Austin-based Introgen filed for banktrupcy and sold its assets after the FDA rejected its application for approval for a drug called Advexin, which was intended to treat head-and-neck cancers.
Mirna was spun off in 2007 from Asuragen Inc., which develops molecular diagnostic tests for cancer and other diseases.
Both companies were founded by Austin biotech veteran Matt Winkler, who sold his first company, Ambion Inc., for $273 million to Applied Biosystems in 2006. The company employs 37 people, with 34 employees based in Austin.
This story was updated at 5 p.m. on Sept. 21 to reflect comments from an interview with Mirna Therapeutics CEO Paul Lammers.
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