Income taxes	3 Months Ended
Mar. 31, 2020
Income taxes
Income taxes	14. Income taxes For the three months ended March 31, 2020 and 2019, we recorded income tax expense of approximately $16.6 million and $1.8 million, respectively. The change in tax expense for the three months ended March 31, 2020 was primarily driven by increased federal and state tax liabilities that are not fully sheltered by net operating losses or research and development tax credit carryforwards. The increase was also driven by reduced tax benefits for stock-based compensation in the current period. As of March 31, 2020, a full valuation allowance continues to be recorded against our U.S. and Swiss net deferred tax assets. Based upon our analysis of our historical operating results, as well as projections of our future taxable income (losses) during the periods in which the temporary differences will be recoverable, we believe the uncertainty regarding the realization of our U.S. and Swiss net deferred tax assets requires a full valuation allowance against such net assets as of March 31, 2020. When performing our assessment on projections of future taxable income (losses), we consider factors such as the likelihood of regulatory approval and commercial success of products currently under development, among other factors. The balance of our unrecognized tax benefits (including penalties and interest) increased by approximately $0.1 million during the three months ended March 31, 2020. The overall net increase is primarily driven by unrecognized tax benefits related to current year operations and research and development tax credits offset by audit settlements in Wisconsin and Italy. After considering valuation allowance impacts, the change in unrecognized tax benefits resulted in a $0.2 million decrease to noncurrent other liabilities on the condensed consolidated balance sheet.

Income taxes

3 Months Ended

Mar. 31, 2020

14. Income taxes

For the three months ended March 31, 2020 and 2019, we recorded income tax expense of approximately $16.6 million and $1.8 million, respectively. The change in tax expense for the three months ended March 31, 2020 was primarily driven by increased federal and state tax liabilities that are not fully sheltered by net operating losses or research and development tax credit carryforwards. The increase was also driven by reduced tax benefits for stock-based compensation in the current period.

As of March 31, 2020, a full valuation allowance continues to be recorded against our U.S. and Swiss net deferred tax assets. Based upon our analysis of our historical operating results, as well as projections of our future taxable income (losses) during the periods in which the temporary differences will be recoverable, we believe the uncertainty regarding the realization of our U.S. and Swiss net deferred tax assets requires a full valuation allowance against such net assets as of March 31, 2020. When performing our assessment on projections of future taxable income (losses), we consider factors such as the likelihood of regulatory approval and commercial success of products currently under development, among other factors.

The balance of our unrecognized tax benefits (including penalties and interest) increased by approximately $0.1 million during the three months ended March 31, 2020. The overall net increase is primarily driven by unrecognized tax benefits related to current year operations and research and development tax credits offset by audit settlements in Wisconsin and Italy. After considering valuation allowance impacts, the change in unrecognized tax benefits resulted in a $0.2 million decrease to noncurrent other liabilities on the condensed consolidated balance sheet.