12.

Stock Option Plan

The Company adopted the 2003 Stock Option Plan, or the 2003 Plan, in 2003, and it was approved by the Company’s stockholders on December 21, 2004. Upon approval of the 2012 Equity Incentive Plan, no additional stock awards may be granted under the 2003 Plan.

The Company adopted the 2012 Equity Incentive Plan, or the 2012 Plan, in May 2012, under which the Company initially reserved for the issuance of 4,000,000 shares of its common stock. The 2012 Plan was approved by the Company’s stockholders on June 20, 2012. On June 18, 2014, the date of the Company’s annual stockholders meeting, the Company’s stockholders approved an amendment to the 2012 Plan increasing the total shares reserved by 5,000,000 shares, for a total of 9,000,000 shares.

As of December 31, 2014, the Company had outstanding options issued to its employees to purchase up to 5,112,800 shares of the Company’s common stock, to its directors to purchase up to 902,529 shares of the Company’s common stock, as well as options to consultants in connection with services rendered to purchase up to 490,334 shares of the Company’s common stock.

Stock options to employees generally vest ratably over three years and have contractual terms of ten years. Stock options to directors generally vest ratably over two or three years and have contractual terms of ten years. Stock options are valued using the Black-Scholes option pricing model and compensation is recognized based on such fair value over the period of vesting on a straight-line basis. The Company has also reserved an aggregate of 26,364 additional shares for issuance under options granted outside of the 2003 Stock Option Plan. The options were granted to The University of Texas M. D. Anderson Cancer Center and DEKK-Tec, Inc. (see Note 8 to the financial statements, Commitments and Contingencies).

Proceeds from the option exercises during the years ended December 31, 2014, 2013, and 2012 amounted to $1.4 million, $956 thousand, and $30 thousand, respectively. The intrinsic value of these options amounted to $2.6 million, $1.4 million and $11 thousand for years ended December 31, 2014, 2013 and 2012, respectively.

Transactions under the Plan for the years ending December 31, 2014, 2013, and 2012 were as follows:


(in thousands, except share and per share data)	Number of Shares			Weighted- Average Exercise Price		Weighted- Average Contractual Term (Years)	Aggregate Intrinsic Value
Outstanding, December 31, 2011		5,138,486			4.08
Granted		2,309,650			4.36
Exercised		(8,300	)		3.61
Cancelled		(292,533	)		5.70

Outstanding, December 31, 2012		7,147,303			4.11
Granted		2,649,900			3.28
Exercised		(570,168	)		1.68
Cancelled		(2,479,732	)		4.58

Outstanding, December 31, 2013		6,747,303			3.81
Granted		1,099,300			4.95
Exercised		(613,138	)		2.26
Cancelled		(727,801	)		4.54

Outstanding, December 31, 2014		6,505,664		$	4.07	7.19	$9,084

Vested and unvested expected to vest at December 31, 2014		6,485,430		$	4.10	5.80	$9,056

Options exercisable, December 31, 2014		3,781,162		$	4.10	5.80	$4,130

Options exercisable, December 31, 2013		3,471,935		$	4.01	5.03	$2,654

Options available for future grant		4,585,769

At December 31, 2014, total unrecognized compensation costs related to non-vested stock options outstanding amounted to $7.9 million. The cost is expected to be recognized over a weighted-average period of 1.62 years.

Restricted Stock

In December 2014, the Company issued 66,828 shares of restricted stock to its non-employee directors, which vest in their entirety on the one year anniversary of the grant date. In December 2013, the Company issued 75,272 shares of restricted stock to its non-employee directors, which vested in their entirety on the one year anniversary of the grant date. In January, February and May 2012, the Company issued 101,500, 43,802 and 25,000 shares of restricted stock to employees, which vested ratably in annual installments over three years, respectively, commencing on the first anniversary of the grant date. In December 2012, the Company also issued 87,730 shares of restricted stock to its non-employee directors, which vested ratably in annual installments over three years, commencing on the first anniversary of the grant date.

In January, February and December 2014, the Company repurchased 16,031, 14,600 and 81,702 shares at average prices of $4.37, $4.40 and $5.04 per share, respectively, to cover payroll taxes. In January, March, May and December 2013, the Company repurchased 52,018, 5,400, 2,623, and 56,683 shares at average prices of $4.28, $4.50, $1.65 and $4.37 per share, respectively, to cover payroll taxes. In July and December 2012, the Company repurchased 15,740 and 107,413 shares at $6.06 and $4.19 per share, respectively, to cover payroll taxes. A summary of the status of non-vested restricted stock as of December 31, 2014, 2013 and 2012 is as follows:


	Number of Shares			Weighted-Average Grant Date Fair Value
Non-vested, December 31, 2011		950,906		$	4.34
Granted		258,032			4.39
Vested		(351,829	)		4.32
Cancelled		(123,370	)		4.34

Non-vested, December 31, 2012		733,739			4.37
Granted		75,272			4.34
Vested		(292,399	)		4.31
Cancelled		(163,747	)		4.42

Non-vested, December 31, 2013		352,865			4.38
Granted		66,828			5.07
Vested		(253,835	)		4.38
Cancelled		(21,350	)		4.41

Non-vested, December 31, 2014		144,508		$	4.70

As of December 31, 2014, there was $471 thousand of total unrecognized stock-based compensation expense related to non-vested restricted stock arrangements. The expense is expected to be recognized over a weighted-average period of 1.00 years.