FOOTHILL RANCH, CALIF. — The US Court of Appeals for the Federal Circuit on Jan. 2 upheld a district court ruling that two PureCircle patents for producing the steviol glycoside sweetener Rebaudioside M (Reb M), also known as Rebaudioside X, were invalid. Both rulings were in favor of Sweegen, which had been sued by PureCircle for alleged patent infringement.

“Throughout this litigation, we consistently asserted the invalidity of PureCircle’s patents, considering their case against Sweegen as baseless and spurious,” said Steven Chen, chief executive officer of Sweegen, Foothill Ranch. “This triumph in the US Court of Appeals serves to highlight Sweegen's dedication to principled innovation and fair competition within the industry.”

The appeals court found claims on US Patent No. 9,243,273 and US Patent No. 10,485,257 were invalid due to a lack of written description and some claims were unpatentable.

“We are disappointed by the court’s decision,” said Nate Yates, global platform leader, sugar reduction and specialty sweeteners for Ingredion, Inc., Westchester, Ill., which acquired a majority stake in PureCircle in 2020. “We are reviewing the opinion in detail while we consider potential next steps. In several ways, this decision and that of the district court show there is strength and value in this patent portfolio. Additionally, PureCircle has a substantial patent portfolio directed to Reb M and other stevia technologies that remain unaffected by the court’s decision.”

Reb M more closely resembles the sweetness of sugar than other steviol glycosides, but it is found in trace amounts in stevia plants. The two patents at issue pertain to a method of producing Reb M more cost effectively by using enzymes called UDP-glucosyltransferases (UGTs).

The first patent was issued on Jan. 26, 2016. PureCircle filed a lawsuit against Sweegen in September of 2018. The US district court on May 24, 2022, ruled in favor of Sweegen and against PureCircle.