Though not as advanced a therapeutic technology as its RNAi cousin, microRNA received a lot of positive attention from the investment community in 2012, with the top companies in the space pulling in nearly $150 million in financing dollars over the past year.
To Simos Simeonidis, a senior research analyst at Cowen Group, such investments reflect a growing appreciation for miRNAs amid advances made with related technologies.
“RNA therapeutics have been making a comeback, so to speak, and the technology has been progressing,” he said, citing as examples positive phase I data on Alnylam Pharmaceuticals' siRNA-based TTR-mediated amyloidosis treatment ALN-TTR02 (GSN 7/19/2012); a partnership between antisense firm Isis Pharmaceuticals and Biogen Idec (GSN 12/13/2012); and strong clinical results with Sarepta Therapeutics' phase II splice-switching oligomer for Duchenne muscular dystrophy.
“All of these things have created a positive environment,” which has raised interest in miRNA drugs from investors in both the public and private markets, he noted.
“Given that it's a very technical field … only the very savvy biotech investors [will] get in,” Simeonidis added. “Those people understand what RNAi is … and what antisense is, and that microRNAs have benefitted from … the chemistry, the formulation, and the delivery” work in those related fields.
Perhaps the most notable evidence of this was the initial public offering of Regulus Therapeutics in October, which marked the first time an miRNA drug-developer began selling its shares to the public (GSN 10/4/2012). Rosetta Genomics closed its IPO in 2007 (GSN 3/1/2007), but that company has essentially abandoned its miRNA therapeutics work in lieu of focusing on diagnostics.
Established as a joint venture between Alnylam and Isis about five years ago, Regulus has made significant progress, both from a scientific and business standpoint — the company has five miRNA inhibitors in its pipeline and two investigational new drug applications expected by 2014, and has forged product-development partnerships with Sanofi, GlaxoSmithKline, and AstraZeneca.
In August, Regulus first disclosed that it was looking to float its stock on the Nasdaq, and the next month it revealed that it was hoping to sell 4.5 million of its shares at $10 to $12 apiece. Combined with an over-allotment option, the firm was aiming to pull in $54 million through the transaction (GSN 9/13/2012).
Apparently overestimating Wall Street's appetite for miRNAs, Regulus later slashed its proposed offering price to $4 a share, while increasing the number of shares offered to 11.25 million, with 1.7 million extra available to cover overallotments.
The IPO raised $50.9 million and, combined with $25 million sold to AstraZeneca in a concurrent private placement and the sale of a $5 million convertible note to Biogen Idec this summer, gave Regulus an $80.9 million financial boost this year — enough cash to fund its operations for three years.
When it comes to private financing, Mirna Therapeutics took top honors for 2012 with its $34.5 million Series C that closed in late October. Founded in 2007 as a spinout of Asuragen, the firm is taking a different approach to the miRNA drugs field by focusing on mimics of the small, non-coding RNAs.
The company has generated encouraging data from several of its programs, with its efforts around a synthetic version of miR-34a, called MRX34, for liver cancer leading the pack. Last year, for instance, Mirna reported that the drug could significantly inhibit lung and liver tumor growth in animal models (GSN 3/24/2011 & 11/17/2011).
Still, Mirna has had some difficulties reaching some of its goals, missing previous guidance around the timing of an IND for MRX34 and the closing of various financing rounds. In October, however, the firm made good on its promise in a big way, securing $34.5 million in funding from both new and existing investors (GSN 10/25/2012).
With the cash infusion, Mirna now has the money to move MRX34 through phase II testing, a key goal that the company expects will yield the proof-of-concept data needed to woo a big pharma partner, according to President and CEO Paul Lammers.
While it might not be quite as large as Mirna's Series C, Miragen Therapeutics' $20 Series B financing in early 2012 was a major milestone for the company (GSN 4/26/2012), which was founded in 2008 to focus on miRNA inhibitors to treat cardiovascular and muscle disorders.
The company said that the money would help advance its pipeline, which includes the heart failure drug MGN-9103, which targets miR-208 and last year was licensed to France's Les Laboratoires Servier (GSN 10/20/2011); MGN-1374, which targets miR-15 and family member miR-195 for post-myocardial infarction remodeling; and MGN-4893, which is designed to inhibit miR-451 for the myeloproliferative disease polycythemia vera.
While it is not purely a miRNA drug firm, Santaris Pharma has been exploring the use of its locked nucleic acid technology to inhibit the ncRNAs, and this summer the company pulled in $12 million through the sale of convertible bonds to existing investors and management team members (GSN 6/21/2012).
According to Santaris, the funding would primarily be used to continue work on the hepatitis C treatment miravirsen, which is designed to silence miR-122 and was the first miRNA-targeting agent to enter human testing.
Currently, the drug is being tested in phase II in combination with direct-acting antiviral drugs. Meantime, Santaris has been conducting early-stage development work with LNA inhibitors of miR-33 for cardiovascular diseases such as hypercholesterolemia after picking up key intellectual property from Massachusetts General Hospital last year (GSN 3/3/2011).
Though not on the same level as other companies in the field, Australian miRNA drugs startup Mireven raised additional capital this year, as well.
The firm was founded in 2010 to develop the discoveries of Western Australian Institute for Medical Research investigator Peter Leedman regarding the role of miR-7 in regulating epidermal growth factor receptor signaling in cancer.
In 2008, he reported that the miRNA down-regulates EGFR mRNA and protein expression in certain cancer cell lines including lung, breast, and glioblastoma, and that the miRNA “attenuated activation of protein kinase B and extracellular signal-regulated kinase 1/2, two critical effectors of EGFR signaling, in different cancer cell lines.”
This year, the company received around $500,000 from investment group Medical Research Commercialization Fund (GSN 9/6/2012), which is expected to help generate in vivo proof-of-concept data showing that miR-7 replacement can be used as a treatment for cancers such as glioblastoma (GSN 9/27/2012).