According to Geoffroy Bessaud of Sanofi-Aventis, the company only became aware of the complaint through reports from various media outlets that emerged over the last 48 hours.
"We are now aware a suit has been filed, but have not yet been served with an official complaint," he told in-PharmaTechnologist.com.
"I assume the Novo Nordisk legal team is still putting together the necessary documents."
However, despite the fact that the company are still in the dark regarding details of the alleged patent infringement, Bessaud said that company will " vigorously defend " its position.
According to Novo Nordisk, Sanofi's SoloStar disposable injection pen system, which was introduced in Germany and France earlier this year, infringes patents that cover the company's NovoPen 4 insulin delivery system.
"In this lawsuit, Novo Nordisk is asserting that it invented and patented features that were used by Sanofi-Aventis to build its injection pen system SoloStar," Lori Moore of Novo told in-PharmaTechnologist.com.
"The patent relates to mechanisms for injecting and dose setting."
The patent the company believes has been infringed is registered in the US, and as such the complaint has been registered in New Jersey with Novo "pursuing a remedy in a US court."
As to whether the company may pursue legal action in other regions, Moore was unwilling to speculate on future litigation, merely commenting that "foreign entities are not immune from suit if the company's conduct constitutes an infringing act in the US."
On Sanofi's side, the company is sitting and waiting to hear before it can make any truly informed statements on the case.
However, Bessaud pointed out that diabetes care represents a major chunk of Novo's business.
In 2006, diabetes care products brought Novo almost DKK28bn (€3.8bn), representing around 70 per cent of the company's total sales for the year.
As such, the company will be keen to defend its franchise from competition, and is no stranger to patent litigation.
The firm has in fact accused Sanofi-Aventis of patent infringement of its insulin pen products before, for example in 2005 claiming that Sanofi's OptiClik pen infringed patents covering Novo's FlexPen device.
However, Bessaud also noted that Novo Nordisk recently voluntarily dismissed two lawsuits regarding delivery products, and that Sanofi would work for a "successful reconciliation" of the case - once they've been informed of it.
Sanofi's SoloStar disposable insulin pen was introduced in Germany and France earlier this year, and received US approval for Lantus SoloStar (a prefilled disposable pen incorporating the company's 24-hour basal insulin Lantus (insulin glargine)) in May.
According to Bessaud, the SoloStar device has been very well received in the markets in which it is available, and the company is very confident that the product will continue to perform well.
So high are the firm's hopes, in fact, that it has established a dedicated manufacturing site in Frankfurt, Germany, which will be able to churn out one million units per day when it reaches maximum capacity.
While the current lawsuit should not affect SoloStar's availability in France and Germany or the company's intended roll-out of the product across Europe over the next year, the US market could now potentially be put out of Sanofi's reach should Novo Nordisk's challenge prove successful.
"We'll know more when we've officially been served," said Bessaud.