6. Intangible and Other Assets, Net

Intangible and other assets, net, were comprised of the following at December 31, 2013 and 2012:


*In thousands*	2013			2012
Capitalized patent and license costs	$	5,975		$	5,975
Less accumulated amortization		(5,007	)		(4,982	)

		968			993
Inventory, non-current		2,985			—
Other assets		1,861			2,131

	$	5,814		$	3,124

Amortization expense for intangible assets was $25,000, $218,000 and $1.7 million in 2013, 2012 and 2011, respectively. The weighted average amortization period for intangible assets was 17.0 years, 17.0 years and 14.9 years in 2013, 2012 and 2011, respectively. The estimated future amortization expense is $28,000 per year for 2014, 2015, 2016, 2017, and 2018 and $828,000 thereafter.

For the years ended December 31, 2012 and 2011, the Company recorded charges to operating expenses of $5.2 million and $312,000, respectively, to reflect impairment of the carrying value of certain capitalized patents and licenses or purchased technology. In 2012, the Company recorded a charge of $4.8 million to reflect impairment of the carrying value of intangible assets associated with ridaforolimus, following the decision in June 2012 by the FDA not to approve the NDA filed by Merck for the treatment of patients with soft tissue or bone sarcomas. The impairment of the carrying value of intangible assets was based on management’s assessment of the uncertainty related to the timing and amount of future cash flows anticipated from these assets. No impairment charges were recorded in 2013.