The following table presents information about the Company’s financial assets that were carried at fair value on a recurring basis on the consolidated balance sheet as of December 31, 2020 and December 31, 2019 and indicates the fair value hierarchy of the valuation inputs utilized to determine such fair value.

The other asset above relates to advance payments made to a supplier that were recorded at fair value using DCF analysis as of December 31, 2020 and December 31, 2019. The fair value measurements of these advance payments were determined based on significant unobservable inputs, including a discount rate of 21% and 15%, as of December 31, 2020 and December 31, 2019, respectively, and the expected time to recovery of the payment. Changes to the inputs described above are not expected to have a material impact on the Company’s financial position and results of operations in any given period.

The carrying amounts reported in the consolidated balance sheets for prepaid expenses and other current assets, accounts payable, accrued expenses and other current liabilities approximate their fair value based on the short-term maturity of these instruments.

The following table presents information about the Company’s debt, Exchangeable Notes, Derivative liability and RLNs. The Company’s long-term debt was carried at amortized cost on the consolidated balance sheet as of December 31, 2020 and December 31, 2019 and indicates the fair value hierarchy of the valuation inputs utilized to determine the approximate fair value.

The book value of the current portion of long-term debt approximates its fair value due to the short-term nature of the balance. The fair value of long-term debt, less current portion was determined based on a DCF analysis using quoted market interest rates, without consideration of transaction costs, which represents a Level 2 basis of fair value measurement. The counterparty to the long-term debt is a major international financial institution.

The Level 3 liabilities held as of December 31, 2020 consist of the embedded exchange option and change of control premium contained in the Exchangeable Notes (see Note 8 - Debt) and a separate financial instrument, that was issued as part of the Units, the RLNs (see Note 9 – Royalty-Linked Notes). The exchange option and change of control premium met the criteria requiring these to be bifurcated and accounted for separately from the host debt in accordance with ASC 815-15, Derivatives and Hedging; Embedded Derivatives. The exchange option and change of control premium are presented as a Derivative liability upon issuance of the Exchangeable Notes under the Private Placement and Rights Offering and are subsequently remeasured to fair value at the end of each reporting period. The Derivative liability, representing the exchange option and change of control premium, was recorded at a fair value of $27,038 at January 21, 2020 and the fair value of the Derivative liability related to the Rights Offering was $82. The fair value of the exchange option and change of control premium at December 31, 2020 amounted to $21,237 and $7,628, respectively. At any time on or after January 21, 2021, subject to specified limitations, the Exchangeable Notes are exchangeable for the Company’s ordinary shares, cash or a combination of ordinary shares and cash, at an exchange rate of 1,286.1845 shares per $1,000 principal and interest on the Exchangeable Note (equivalent to an exchange price of approximately $0.7775 per ordinary share) as of November 2, 2020, what was adjusted from the initial exchange rate of 1,000 shares per $1,000 of principal and interest on the Exchangeable Notes (equivalent to an initial exchange price of approximately $1.00 per ordinary share and is subject to further adjustment pursuant to the terms of the indenture governing the Exchangeable Notes.

In the event of a fundamental change that is not a liquidation event (Fundamental Change), under the indenture governing the Exchangeable Note, the Company will be required to pay the holders of the Exchangeable Notes the greater of three times the outstanding principal amount of such Exchangeable Notes and the consideration that would be received by the holders of such Exchangeable Notes, in connection with such Fundamental Change, if the holders had exchanged their notes for ordinary shares immediately prior to the consummation of such Fundamental Change, plus any accrued and unpaid interest. The Derivative liability, representing the change of control feature, was recorded at a fair value of $7,628 at December 31, 2020.

The fair value of each component of the Derivative liability was determined using a valuation technique applying DCF analysis or Black-Scholes in combination with binomial lattice models, without consideration of transaction costs, which represents a Level 3 basis of fair value measurement. The key inputs to valuing the Derivative liability as of December 31, 2020 include the indenture terms of the Exchangeable Notes, the Company’s share price at the exchange date, the expected annual volatility of the Company’s ordinary shares, management’s assumption regarding the probability of a fundamental change pursuant to the terms of the indenture governing the Exchangeable Notes, and a risk-adjusted discount rate. Fair value measurements are highly sensitive to changes in these inputs and significant changes in these inputs could result in a significantly higher or lower fair value.

The following table presents the changes in fair value of the Company's Derivative liability for the year ended December 31, 2020:

The following summary table shows the assumptions used in the Black-Scholes and binomial lattice pricing models to estimate the fair value of the exchange option:

The significant assumptions used in the DCF model, to estimate the fair value of the change of control feature at December 31, 2020, were a discount rate of 21% and management’s assumption regarding the probability of a fundamental change pursuant to the terms of the indenture governing the Exchangeable Notes.

 The RLN liability is carried at amortized cost on the consolidated balance sheet as of December 31, 2020 (see Note 9 – Royalty-Linked Notes). The book value of the current portion of the RLN liability approximates its fair value due to the short-term nature of the balance. The total fair value of $16,493 was determined using DCF analysis, without consideration of transaction costs, which represents a Level 3 basis of fair value measurement. The key inputs to valuing the RLNs were the indenture terms of the RLNs, the expected cash flows to be received by holders of the RLNs based on management’s revenue forecasts of U.S. sulopenem sales and a risk-adjusted discount rate to derive the net present value of expected cash flows. The RLNs will be subject to a maximum return amount, including all principal and payments and certain default interest in respect of uncurable defaults, of $160.00 (or 4,000 times the principal amount of such note). The discount rate applied to the model was 21%. Fair value measurements are highly sensitive to changes in these inputs and significant changes in these inputs could result in a significantly higher or lower fair value.

There have been no transfers of assets or liabilities between the fair value measurement levels.