Regulus Therapeutics has gone public, following a by-now familiar pattern for biotech initial public offerings. The San Diego-based developer of microRNA therapeutics slashed its offering price to $4.00 a share, almost two thirds below its target range of $10 to $12. It also raised the number of shares offered to 11.25 million, more than double its original plan to offer 4.5 million shares.

But Regulus got the deal done, raised $45 million, and began trading on the Nasdaq with shares hitting the market at $4.73 and ending the first day at $4.20, up 5 percent. GlobeImmune, on the other hand, has delayed its offering two weeks in a row, still hoping to price in its target range of $11 to $13.

Of the nine therapeutics developers that have gone public so far this year, seven (including Regulus) have had to drop their expectations in order to get their deal done. The best performer of the group, Supernus Pharmaceuticals, is up more than 130 percent but it had to slash its offering price 61.5 percent in order to go public.

In the meantime, a number of biotech companies have tested the waters through confidential filings under the newly approved JOBS Act or have recently filed publicly with the SEC. Besides Regulus, these include GlobeImmune, Intercept Pharmaceuticals, Paratek Pharmaceuticals, and the diagnostics makers AutoGenomics and Singulex.

Regulus Therapeutics was formed in 2007 by Alnylam Pharmaceuticals and Isis Pharmaceuticals, two leaders in RNAi therapeutics, to discover and develop innovative medicines targeting microRNAs, small RNA molecules that do not encode proteins but instead regulate gene expression.

Just before Regulus announced its intention to go public, it bolstered its value with two deals. A strategic alliance with AstraZeneca in cardiovascular and metabolic diseases and cancer brought in $28 million in cash and a commitment from the Big Pharma to invest $25 million in a concurrent private equity placement in Regulus.

Regulus also said it would work with Biogen Idec to identify microRNAs as biomarkers for multiple sclerosis. Biogen Idec too is making an investment in Regulus as part of the deal, in addition to an upfront payment and potential milestones. Regulus also has strategic alliances with GlaxoSmithKline and Sanofi. Both AstraZeneca and GSK said they would invest in the IPO, although it was non-binding.

In its regulatory filing, Regulus says it will use the proceeds from the IPO to advance the development of its pipeline, with plans to advance two pipeline candidates into the clinic in year ahead.