Net Product Sales

In November 2011, the Company received marketing approval from the FDA for EYLEA (aflibercept) Injection for the treatment of wet AMD. In September 2012, the Company received marketing approval from the FDA for EYLEA for the treatment of macular edema following CRVO. EYLEA net product sales totaled $837.9 million and $24.8 million for the years ended December 31, 2012 and 2011, respectively.

In February 2008, the Company received marketing approval from the FDA for ARCALYST Injection for Subcutaneous Use for the treatment of CAPS. ARCALYST net product sales totaled $20.2 million, $19.9 million, and $25.3 million for the years ended December 31, 2012, 2011, and 2010, respectively. The Company had limited historical returns experience for ARCALYST beginning with initial sales in 2008 through the end of 2009; therefore, ARCALYST net product sales were deferred until the right of return no longer existed and rebates could be reasonably estimated. Effective in the first quarter of 2010, the Company determined that it had accumulated sufficient historical data to reasonably estimate both product returns and rebates of ARCALYST. As a result, ARCALYST net product sales during 2010 included $20.5 million of net product sales made during this period and $4.8 million of previously deferred net product sales. The effect of recognizing the previously deferred ARCALYST net product sales revenue was to lower the Company's net loss per share by $0.06 in 2010.

For the years ended December 31, 2012 and 2011, the Company recorded 78% and 42%, respectively, of its total gross product revenue from sales to Besse Medical, a subsidiary of AmerisourceBergen Corporation.

Revenue from product sales are recorded net of applicable provisions for rebates and chargebacks under governmental programs (including Medicaid), distribution-related fees, prompt pay discounts, product returns, and other sales-related deductions. The following table summarizes the provisions, and credits/payments, for these sales-related deductions; such amounts were not significant during the year ended December 31, 2011.



	Rebates & Chargebacks			Distribution- Related Fees			Other Sales- Related Deductions			Total
Balance as of December 31, 2011	$	585		$	1,451		$	182		$	2,218
Provision related to current period sales	14,153			45,028			3,070			62,251
Credits/payments	(11,755		)	(31,181		)	(2,707		)	(45,643		)
Balance as of December 31, 2012	$	2,983		$	15,298		$	545		$	18,826