. Summary of Significant Accounting Policies

Revenue Recognition

All of the Company’s revenue is derived from long-term contracts that span multiple years. The Company accounts for revenue in accordance with ASC Topic

606,

Revenue from Contracts with Customers

(“ASC

606”

). A contract’s transaction price is allocated to distinct performance obligations and recognized as revenue when, or as, a performance obligation is satisfied. As of

March 31, 2020

, the Company's active performance obligations, for the contracts outlined in

Note

, consist of the following:

five

performance obligations relate to research and development services;

one

relates to manufacture and delivery of product; and

one

is associated with storage of product. The aggregate amount of transaction price allocated to remaining performance obligations was

$47.0

million as of

March 31, 2020

. Remaining performance obligations represent the transaction price for which work has

not

been performed and excludes unexercised contract options.

Contract Balances

The timing of revenue recognition, billings and cash collections

may

result in billed accounts receivable, unbilled receivables (contract assets) and customer advances and deposits (contract liabilities) in the condensed consolidated balance sheets. Generally, amounts are billed as work progresses in accordance with agreed-upon contractual terms either at periodic intervals (monthly) or upon achievement of contractual milestones. Under typical payment terms of fixed price arrangements, the customer pays the Company either performance-based payments or progress payments. For the Company’s cost-type arrangements, the customer generally pays the Company for its actual costs incurred, as well as its allocated overhead and G&A costs. Such payments occur within a short period of time from billing. When the Company receives consideration, or such consideration is unconditionally due, prior to transferring goods or services to the customer under the terms of a sales contract, the Company records deferred revenue, which represents a contract liability. During the

three

months ended

March 31, 2020

, the Company recognized reven

ue of

$0.1

million t

hat was included in deferred revenue at the beginning of the period.

Restricted Cash and Cash Equivalents

March 13, 2020,

the Company repaid its Term Loan and restrictions on certain cash accounts were removed. Prior to the repayment of the Term Loan, there were restrictions on certain cash accounts. Under the terms of the Loan Agreement (as defined below), net cash proceeds from the Company's Priority Review Voucher ("PRV") sale on

October 31, 2018

were restricted and were held in a reserve accoun

t (as required under the Loan Agreement related to the Term Loan). Cash

and cash equivalents held in the reserve account were available to pay interest, fees and principal related to the Term Loan. See

Note

for additional information. Prior to the

second

quarter of

2019,

there was also a reserve account for certain proceeds of the Term Loan. This account was also restricted. Amounts in this reserve account were primarily used to pay interest on the Loan Agreement. This reserve account was closed in the

second

quarter

2019.

The following tables reconcile cash, cash equivalents and restricted cash per the condensed consolidated statements of cash flows to the condensed consolidated balance sheet for each respective period:

	As of
	March 31, 2020		December 31, 2019
Cash and cash equivalents	$	77,377,300	$	65,249,072
Restricted cash-short term		—		95,737,862
Cash, cash equivalents and restricted cash	$	77,377,300	$	160,986,934

	March 31, 2019		December 31, 2018
Cash and cash equivalents	$	102,085,215	$	100,652,809
Restricted cash-short term		11,461,290		11,452,078
Restricted cash-long term		66,794,243		68,292,023
Cash, cash equivalents and restricted cash	$	180,340,748	$	180,396,910

Repurchase of shares

When shares recognized as equity are repurchased, the amount of the consideration paid, which includes directly attributable costs, is recognized as a deduction from equity. The excess of the purchase price above par value of repurchased shares that are retired is presented as an increase to accumulated deficit (or a reduction of retained earnings, if any).