7. INTANGIBLE ASSETS

Intangible assets, included in “other assets,” consisted of patent licensing fees paid to license intellectual property. In July 2007, the Company entered into a worldwide exclusive license (the “BCH License”) for patents co-owned by BCH and MIT initially covering the use of biopolymers to treat spinal cord injuries, and to promote the survival and proliferation of human stem cells in the spinal cord. During 2011, the BCH License was amended, and the Company obtained additional rights for use in the field of peripheral nerve injuries. The BCH License, as amended, has a 15‑year term, or as long as the life of the last expiring patent right thereunder, whichever is longer, unless terminated earlier by the licensor, under certain conditions as defined in the related license agreement. In connection with the BCH License, the Company paid an initial $75 thousand licensing fee and is required to pay certain annual maintenance fees, milestone payments and royalties. License fees are capitalized and the gross total at June 30, 2020 and December 31, 2019 was $200 thousand. The Company accounts for milestone payments, maintenance fees and royalties when they become due and payable. During the three and six months ended June 30, 2020 and 2019, the Company did not pay any milestone payments. The Company is amortizing the license fee as a research and development expense over the 15– year term of the license.

Intangible assets, net consisted of the following:


	June 30,		December 31,
(In thousands)	2020		2019
Patent licensing fee	$	200	$	200
Accumulated amortization		(183)		(174)
Intangible assets, net	$	17	$	26

Amortization expense during each of the three and six months ended June 30, 2020 and 2019 was $5 thousand and $9 thousand, respectively.