Derivative Liability

12 Months Ended

Dec. 31, 2020

Derivative Liability

Derivative Liability

5. DERIVATIVE LIABILITY

Exit Fee

In May 2018, in connection with entering into the Loan Agreement, as defined and discussed in Note 6, the Company entered into an agreement pursuant to which the Company agreed to pay $1.5 million in cash, or the Exit Fee, upon any change of control transaction in respect of the Company or if the Company obtains both (i) FDA approval of tenapanor for the treatment of hyperphosphatemia in CKD patients on dialysis and (ii) FDA approval of tenapanor for the treatment of patients with irritable bowel syndrome with constipation, or IBS-C, which was obtained on September 12, 2019 when the FDA approved IBSRELA® (tenapanor), a 50 mg, twice daily oral pill for the treatment of IBS-C, in adults (the “Exit Fee Agreement”). Notwithstanding the prepayment or termination of the Term Loan, the Company’s obligation to pay the Exit Fee will expire on May 16, 2028. The Company concluded that the Exit Fee is a freestanding derivative which should be accounted for at fair value on a recurring basis. The estimated fair value of the Exit Fee is recorded as a derivative liability and included in accrued expense and other current liabilities on the accompanying balance sheets.

The fair value of the derivative liability was determined using a discounted cash flow analysis and is classified as a Level 3 measurement within the fair value hierarchy since the Company’s valuation utilized significant unobservable inputs. Specifically, the key assumptions included in the calculation of the estimated fair value of the derivative instrument include: i) the Company’s estimates of both the probability and timing of a potential $1.5 million payment to Solar Capital Ltd. and Western Alliance Bank as a result of the FDA approvals, and ii) a discount rate which was derived from the Company's estimated cost of debt, adjusted with current LIBOR. Generally, increases or decreases in the probability of occurrence would result in a directionally similar impact in the fair value measurement of the derivative instrument and it is estimated that a 10% increase (decrease), not to exceed 100%, in the probability of occurrence would result in a fair value fluctuation of no more than $0.1 million.

Changes in the fair value of recurring measurements included in Level 3 of the fair value hierarchy are presented as other income (expense), net in the Company's statements of operations and were as follows for the years ended December 31, 2020, 2019 and 2018 (in thousands):

		2020		2019		2018
Fair value of Exit Fee derivative liability at January 1	$	969	$	533		—
Change in estimated fair value of derivative liability		407		436		533
Fair value of Exit Fee derivative liability at December 31	$	1,376	$	969	$	533