$52.6 million of the net product sales outside of the United States for the three months ended June 30, 2022 and 2021, respectively. For the three months ended June 30, 2022 and 2021, the Company had a total of 2 and 2 distributors, respectively, that each accounted for over 10% of the Company’s net product sales.
During the six months ended June 30, 2022 and 2021, net product sales in the United States were $105.4 million and $92.7 million, respectively, consisting solely of Emflaza, and net product sales outside of the United States were $168.1 million and $101.7 million, respectively, consisting of Translarna, Tegsedi, Waylivra, and Upstaza. Upstaza sales commenced during the six months period ended June 30, 2022. Translarna net revenues made up $156.2 million and $99.1 million of the net product sales outside of the United States for the six months ended June 30, 2022 and 2021, respectively. For the six months ended June 30, 2022 and 2021, the Company had a total of 2 and 2 distributors, respectively, that each accounted for over 10% of the Company's net product sales.
As of June 30, 2022 and December 31, 2021, the Company did 0t have any contract liabilities or assets. For the three and six months ended June 30, 2022, the Company did 0t recognize any revenue related to the amounts included in the contract liability balance at the beginning of the period. During the three and six months ended June 30, 2021, the Company recognized $1.9 million and $4.0 million of revenue, respectively, related to the amounts included in the contract liability balance at the beginning of the period. The Company has not made significant changes to the judgments made in applying ASC Topic 606 for the three and six months ended June 30, 2022 and 2021.
Remaining performance obligations
Remaining performance obligations represent the transaction price for goods the Company has yet to provide. As of June 30, 2022 and December 31, 2021 the Company does 0t have any remaining performance obligations relating to Translarna net product revenue.
Collaboration and Royalty revenue
In November 2011, the Company and the SMA Foundation entered into the SMA License Agreement with Roche. Under the terms of the SMA License Agreement, Roche acquired an exclusive worldwide license to the Company’s SMA program.
Under the SMA License Agreement, the Company is eligible to receive additional payments from Roche if specified events are achieved with respect to each licensed product, including up to $135.0 million in research and development event milestones, up to $325.0 million in sales milestones upon achievement of specified sales events, and up to double digit royalties on worldwide annual net sales of a commercial product.
The SMA program currently has one approved product, Evrysdi, which was approved in August 2020 by the FDA for the treatment of SMA in adults and children two months and older. As of June 30, 2022, the Company does 0t have any remaining research and development event milestones that can be received. The remaining potential sales milestones that can be received is $300.0 million.
For the three months ended June 30, 2022 and 2021, the Company did 0t recognize collaboration revenue related to the SMA License Agreement. For the six months ended June 30, 2022 and 2021, the Company recognized collaboration revenue related to the SMA License Agreement of $0.0 million and $20.0 million, respectively. The first commercial sale of Evrysdi in the EU was made in March 2021. This event triggered a $20.0 million milestone payment to the Company from Roche for the six months ended June 30, 2021.
In addition to research and development and sales milestones, the Company is eligible to receive up to double-digit royalties on worldwide annual net sales of a commercial product under the SMA License Agreement. For the three and six months ended June 30, 2022, the Company has recognized $21.8 million and $40.7 million of royalty revenue, respectively, related to Evrysdi. For the three and six months ended June 30, 2021, the Company has recognized $13.6 million and $20.2 million of royalty revenue, respectively, related to Evrysdi.