Stockholders' Equity

6 Months Ended

Jun. 30, 2015

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Stockholders' Equity

Warrants 

As of June 30, 2015 the following warrants for common stock were issued and outstanding:

Issue date	Expiration date	Exercise price		Number of warrants outstanding
April 4, 2011	April 4, 2016	$	6.74	1,288,107
November 21, 2012	November 21, 2017	$	7.86	985,036
				2,273,143

On April 4, 2011 and November 21, 2012 the Company's wholly owned subsidiary, MethylGene, completed private placement financing transactions which resulted in the issuance of common stock warrants. The April 4, 2011 common stock warrants were issued with an exercise price of CND$7.46 (USD$6.74 as amended) and the November 21, 2012 common stock warrants were issued with an exercise price of CND$8.70 (USD$7.86 as amended). During the last half of 2014, the Company amended all of these outstanding warrant agreements to allow for the warrants to be denominated in U.S. Dollars.

During the three and six months ended June 30, 2015, warrants for 179,296 and 192,570 shares, respectively, of the Company's common stock were exercised via cashless exercises and the Company issued a total of 139,503 and 148,818 shares, respectively, of common stock.

Stockholders' Equity

Sale of Common Stock

In February 2015, the Company completed a follow-on offering whereby it issued an aggregate 2,587,500 shares of common stock at $20.00 per share. Proceeds from the follow-on offering, net of underwriting discounts, commissions and offering expenses, were $48.4 million.

Share-based Compensation

Total share-based compensation expense by operating statement classification is presented below (in thousands):

	Three Months Ended June 30,				Six Months Ended June 30,
	2015		2014		2015		2014
Research and development expense	$	931	$	582	$	1,739	$	1,070
General and administrative expense	1,861		703		3,369		1,161
	$	2,792	$	1,285	$	5,108	$	2,231

During the three and six months ended June 30, 2015, 4,750 and 26,916 shares, respectively, were issued pursuant to stock option exercises generating net proceeds of $0.1 million and $0.3 million, respectively, for each period.