In 2021, the Company disposed of its previous research program through the sale of assets and certain related liabilities to NeuBase Therapeutics, Inc. (NeuBase) in exchange for cash and shares of NeuBase common stock. The shares have certain restrictions on sale or transfer.

Fair value of this asset is determined using alternative pricing sources and models utilizing market observable inputs. The Company reports the restricted equity securities as non-marketable equity securities on the condensed balance sheet and determines current or non-current classification based on the expected duration of the restriction.

The carrying value is measured as the total initial cost, less the cumulative net unrealized loss. The following table summarizes the value of non-marketable equity securities using the measurement alternative (in thousands):


	June 30, 2023			December 31, 2022
Initial cost	$	1,759		$	1,759
Cumulative net fair value adjustments		(1,730	)		(1,701	)
Total non-marketable equity securities	$	29		$	58