DEBT

The amortized carrying amount of our debt consists of the following (in thousands):



	June 30, 2017		December 31, 2016
Secured Convertible Notes due 2018 (“Deerfield Notes”)	$	—	$	109,122
Term loan payable	—		80,000
Total debt	$	—	$	189,122

See “Note 7 - Debt” to our Consolidated Financial Statements included in our Annual Report on Form 10-K for the year ended December 31, 2016 filed with the SEC on February 27, 2017 for additional information on the terms of our debt, including a description of the material features of the Deerfield Notes.

Deerfield Notes

On June 28, 2017, we repaid all amounts outstanding under the Deerfield Notes. The repayment amount totaled $123.8 million which comprised $113.9 million in principal, including $13.9 million of interest paid in kind paid through the repayment date, a $5.8 million prepayment penalty associated with the early repayment of the notes and $4.2 million in accrued and unpaid interest. As a result of the early repayment, there was a $6.2 million loss on the extinguishment of the debt which comprised the prepayment penalty and the unamortized fees and costs on the date of the repayment.

Prior to our early repayment of the notes, the outstanding principal amount of the Deerfield Notes bore interest at the rate of 7.5% per annum to be paid in cash, quarterly in arrears, and 7.5% per annum to be paid in kind, quarterly in arrears, for a total interest rate of 15% per annum. The following is a summary of interest expense for the Deerfield Notes (in thousands):



	Three Months Ended June 30,				Six Months Ended June 30,
	2017		2016		2017		2016
Stated coupon interest	$	2,083	$	1,972	$	4,151	$	3,908
Interest paid in kind	2,083		1,972		4,151		3,908
Amortization of debt discount and debt issuance costs	93		113		182		206
Total interest expense	$	4,259	$	4,057	$	8,484	$	8,022

The balance of unamortized fees and costs was $0.4 million as of December 31, 2016, which was recorded as a reduction of the carrying amount of the Deerfield Notes on the accompanying Condensed Consolidated Balance Sheet.

Silicon Valley Bank Loan and Security Agreement

On March 29, 2017, we repaid all amounts outstanding under our term loan with Silicon Valley Bank. The repayment included $80.0 million in principal plus $0.1 million in accrued and unpaid interest. There was no gain or loss on the extinguishment of debt as a result of the repayment of the term loan. Prior to our early repayment of the term loan, the principal amount outstanding under the term loan had accrued interest at 1.0% per annum, which was due and payable monthly.

In accordance with the terms of the loan and security agreement, we were required to maintain an amount equal to at least 100%, but not to exceed 107%, of the outstanding principal balance of the term loan on deposit in one or more investment accounts with Silicon Valley Bank or one of its affiliates as support for our obligations under the loan and security agreement. We were entitled to retain income earned on the amounts maintained in such accounts. The total collateral balance as of December 31, 2016 was $81.6 million and was reflected in our Condensed Consolidated Balance Sheet in Short-term investments as the amounts were not restricted as to withdrawal. As a result of our repayment of the term loan, the compensating balance requirement was terminated as of March 29, 2017.