Net Income (Loss) Per Share

Under the two-class method, for periods with net income, basic net income per common share is computed by dividing the net income attributable to common stockholders by th

e weighted average number of shares of common stock outstanding during the period. Net income attributable to common stockholders is computed by subtracting from net income the portion of current year earnings that participating securities would have been entitled to receive pursuant to their dividend rights had all of the year’s earnings been distributed. No such adjustment to earnings is made during periods with a net loss as the holders of the participating securities have no obligation to fund losses. Diluted net loss per common share is computed under the two-class method by using the weighted average number of shares of common stock outstanding plus, for periods with net income attributable to common stockholders, the potential dilutive effects of stock options and warrants. In addition, the Company analyzes the potential dilutive effect of the outstanding participating securities under the if-converted method when calculating diluted earnings per share in which it is assumed that the outstanding participating securities convert or are reclassified into common stock at the beginning of the period. The Company reports the more dilutive of the approaches (two-class or if-converted) as its diluted net income per share during the period. Due to the existence of net losses for the three and six month periods ended June 30, 2015, basic and diluted loss per share were the same, as the effect of potentially dilutive securities would have been anti-dilutive.

The following securities, presented on a com

mon stock equivalent basis, have been excluded from the calculation of weighted-average shares of common stock outstanding for the three and six month periods ended June 30, 2016 and 2015 because their effect is anti-dilutive:

	Three and Six Months Ended June 30,
	2016		2015
Warrants to purchase common stock		164,400		2,650,212
Awards under equity incentive plans		2,238,153		943,304
Deerfield Convertible Notes		2,088,931		1,896,843
2021 Notes		5,040,914		—
Total		9,532,398		5,490,359

The following table reconciles basic earnings per share of common stock to diluted earnings per share of common stock for the three and six months ended June 30, 2016 (in thousands, except per share data)

	Three Months Ended			Six Months Ended
	June 30, 2016
Basic earnings per share of common stock:
Net earnings	$	9,768		$	6,834
Less: Net earnings allocable to participating securities		(1,137	)		(798	)
Net earnings allocable to shares of common stock		8,631			6,036
Less: Dividends declared or accumulated		—			—
Undistributed earnings allocable to shares of common stock, basic	$	8,631		$	6,036
Weighted-average shares of common stock outstanding		14,597			14,547
Basic earnings per share of common stock	$	0.59		$	0.41
Diluted loss per share of common stock:
Net earnings	$	9,768		$	6,834
Less: Fair value adjustment for Deerfield stock warrants		(18,769	)		(28,001	)
Net loss allocable to shares of common stock, diluted	$	(9,001	)	$	(21,167	)
Weighted-average shares of common stock outstanding		14,597			14,547
Dilutive effect of Deerfield stock warrants		838			1,037
Weighted-average shares of common stock outstanding, diluted		15,435			15,583
Diluted loss per share of common stock	$	(0.58	)	$	(1.36	)