Note 5 - Revenue	3 Months Ended
Mar. 31, 2021
Notes to Financial Statements
Revenue [Text Block]	NOTE 5. Revenue Service Contracts with Customers Contract Balances. Accounts receivable related to service contracts with customers as of March 31, 2021 and December 31, 2020, was $232,000 and nil, respectively. Contract assets, representing unbilled receivables where revenue has been recognized in advance of customer billings, as of March 31, 2021 and December 31, 2020, was nil and $219,000, respectively, which is included in prepaid expenses and other current assets. Remaining Performance Obligations. Remaining Performance Obligations (“RPO”) comprise deferred revenue plus unbilled contract revenue. As of March 31, 2021 and December 31, 2020, there was no deferred revenue and the aggregate amount of RPO was nil and $13,000, respectively, all of which was unbilled contract revenue which is not recorded on the balance sheet. Unbilled contract revenue represents non-cancelable contracts under which the Company has an obligation to perform, for which revenue has not yet been recognized in the financial statements and the fixed amounts billable have not yet been invoiced. Royalty Agreements Aviragen entered into a royalty-generating research and license agreement with GlaxoSmithKline, plc (“GSK”) in 1990 for the development and commercialization of zanamivir, a neuraminidase inhibitor marketed by GSK as Relenza, to treat influenza. All of the Company’s Relenza patents have expired, with the last remaining patent expiring in July 2019 in Japan, at which time royalty revenue ceased, although until April 30, 2020, it remained subject to adjustments for sales returns and exchange rate differences. There was no royalty revenue related to Relenza recognized in the three months ended March 31, 2021 or 2020. The Company also generates royalty revenue from the sale of Inavir in Japan, pursuant to a collaboration and license agreement that Aviragen entered into with Daiichi Sankyo Company, Limited (“Daiichi Sankyo”) in 2009. In September 2010, laninamivir octanoate was approved for sale by the Japanese Ministry of Health and Welfare for the treatment of influenza in adults and children, which Daiichi Sankyo markets as Inavir. Under the agreement, the Company currently receives a 4% royalty on net sales of Inavir in Japan. The last patent related to Inavir is set to expire in December 2029, at which time royalty revenue will cease. The royalty revenue related to Inavirrecognized in the three months ended March 31, 2021 and 2020, was nil and $2,769,000, respectively, representing 4% of net sales in Japan. In addition, the Company recognized non-cash royalty revenue related to the sale of future royalties (see Note 6) of $493,000 and $34,000 in the three months ended March 31, 2021 and 2020, respectively. Both the royalty revenue and the non-cash royalty revenue related to sale of future royalties have been subjected to a 5% withholding tax in Japan, for which $25,000 and $140,000 was included in income tax expense in the three months ended March 31, 2021 and 2020, respectively. The Company’s royalty revenue is seasonal, in line with the flu season, so the majority of the Company’s royalty revenue is earned in the first and fourth fiscal quarters.

Note 5 - Revenue

3 Months Ended

Mar. 31, 2021

NOTE 5. Revenue

Service Contracts with Customers

Contract Balances. Accounts receivable related to service contracts with customers as of March 31, 2021 and December 31, 2020, was $232,000 and nil, respectively. Contract assets, representing unbilled receivables where revenue has been recognized in advance of customer billings, as of March 31, 2021 and December 31, 2020, was nil and $219,000, respectively, which is included in prepaid expenses and other current assets.

Remaining Performance Obligations. Remaining Performance Obligations (“RPO”) comprise deferred revenue plus unbilled contract revenue. As of March 31, 2021 and December 31, 2020, there was no deferred revenue and the aggregate amount of RPO was nil and $13,000, respectively, all of which was unbilled contract revenue which is not recorded on the balance sheet. Unbilled contract revenue represents non-cancelable contracts under which the Company has an obligation to perform, for which revenue has not yet been recognized in the financial statements and the fixed amounts billable have not yet been invoiced.

Royalty Agreements

Aviragen entered into a royalty-generating research and license agreement with GlaxoSmithKline, plc (“GSK”) in 1990 for the development and commercialization of zanamivir, a neuraminidase inhibitor marketed by GSK as Relenza, to treat influenza. All of the Company’s Relenza patents have expired, with the last remaining patent expiring in July 2019 in Japan, at which time royalty revenue ceased, although until April 30, 2020, it remained subject to adjustments for sales returns and exchange rate differences. There was no royalty revenue related to Relenza recognized in the three months ended March 31, 2021 or 2020.

The Company also generates royalty revenue from the sale of Inavir in Japan, pursuant to a collaboration and license agreement that Aviragen entered into with Daiichi Sankyo Company, Limited (“Daiichi Sankyo”) in 2009. In September 2010, laninamivir octanoate was approved for sale by the Japanese Ministry of Health and Welfare for the treatment of influenza in adults and children, which Daiichi Sankyo markets as Inavir. Under the agreement, the Company currently receives a 4% royalty on net sales of Inavir in Japan. The last patent related to Inavir is set to expire in December 2029, at which time royalty revenue will cease. The royalty revenue related to Inavirrecognized in the three months ended March 31, 2021 and 2020, was nil and $2,769,000, respectively, representing 4% of net sales in Japan. In addition, the Company recognized non-cash royalty revenue related to the sale of future royalties (see Note 6) of $493,000 and $34,000 in the three months ended March 31, 2021 and 2020, respectively. Both the royalty revenue and the non-cash royalty revenue related to sale of future royalties have been subjected to a 5% withholding tax in Japan, for which $25,000 and $140,000 was included in income tax expense in the three months ended March 31, 2021 and 2020, respectively.

The Company’s royalty revenue is seasonal, in line with the flu season, so the majority of the Company’s royalty revenue is earned in the first and fourth fiscal quarters.