Stock-Based Compensation

3 Months Ended

Jun. 30, 2011

Stock-Based Compensation

4. Stock-Based Compensation

The Company uses the Black-Scholes option pricing model to calculate the fair value of share-based awards on the grant date.

For the three months ended June 30, 2011 and 2010, the Company recorded stock-based compensation expense of approximately $282,000 and $263,000, respectively, for stock options granted under the Second Amended and Restated 2001 Repligen Corporation Stock Plan (the “2001 Plan”).

The 2001 Plan allows for the granting of incentive and nonqualified options and restricted stock and other equity awards to purchase shares of common stock. Incentive options granted to employees under the 2001 Plan generally vest over a four to five-year period, with 20%-25% vesting on the first anniversary of the date of grant and the remainder vesting in equal yearly installments thereafter. Nonqualified options issued to non-employee directors and consultants under the 2001 Plan generally vest over one year. Options granted under the 2001 Plan have a maximum term of ten years from the date of grant and generally, the exercise price of the stock options equals the fair market value of the Company’s common stock on the date of grant. At June 30, 2011, options to purchase 2,573,800 shares were outstanding under the 2001 Plan and the 1992 Repligen Corporation Stock Option Plan (collectively with the 2001 Plan, the “Plans”). At June 30, 2011, 269,609 shares were available for future grant under the 2001 Plan.

The Company recognizes stock-based compensation expense on a straight-line basis over the requisite service period based upon options that are ultimately expected to vest, and accordingly, such compensation expense has been adjusted by an amount of estimated forfeitures. Forfeitures represent only the unvested portion of a surrendered option. Forfeitures are estimated at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates.

Information regarding option activity for the three months ended June 30, 2011 under the Plans is summarized below:

	Options Outstanding			Weighted- Average Exercise Price Per Share		Weighted- Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value
Options outstanding at April 1, 2011		2,580,600		$	4.15
Granted		16,000			4.00
Exercised		—			—
Forfeited/Cancelled		(22,800	)		4.90
Options outstanding at June 30, 2011		2,573,800		$	4.14		6.19	$	783,722
Options exercisable at June 30, 2011		1,558,500		$	4.16		4.75	$	603,947
Vested and expected to vest at June 30, 2011 (1)		2,446,768		$	4.13		6.08	$	767,026

(1) This represents the number of vested options as of June 30, 2011 plus the number of unvested options expected to vest as of June 30, 2011 based on the unvested outstanding options at June 30, 2011 adjusted for estimated forfeiture rates of 8% for awards granted to non-executive level employees and 3% for awards granted to executive level employees.

The aggregate intrinsic value in the table above represents the total pre-tax intrinsic value (the difference between the closing price of the common stock on June 30, 2011 of $3.64 and the exercise price of each in-the-money option) that would have been received by the option holders had all option holders exercised their options on June 30, 2011.

The weighted average grant date fair value of options granted during the three months ended June 30, 2011 and 2010 was $2.24 and $1.97, respectively. The total fair value of stock options that vested during the three months ended June 30, 2011 and 2010 was approximately $340,083 and $405,859, respectively.

As of June 30, 2011, there was approximately $1,705,988 of total unrecognized compensation cost related to unvested share-based awards. This cost is expected to be recognized over a weighted average remaining requisite service period of 2.99 years. The Company expects approximately 888,268 in unvested options to vest over the next five years.