“We believe that, as shown in this case, a 20-fold difference is sufficient to support the finding of an unexpected result, when a 2-fold difference would otherwise have been expected by those skilled in the art. We believe that.” – CAFC
Yesterday, the U.S. Court of Appeals for the Federal Circuit (CAFC) upheld the validity of multiple claims in two of Amgen’s patents, barring Sandoz and Zydus from manufacturing generic versions of Amgen’s psoriasis drug Otezla. upheld the court’s ruling. The CAFC decision also upheld the district court’s ruling that Amgen’s three claims of US Patent 10,092,541 were invalid. But that didn’t stop Amgen from declaring victory in the lawsuit in a press release.
Two patents that have not been shown to be invalid are US Patent 7,427,638 and US Patent 7,893,101. All three patents relate to Amgen’s psoriasis drug Otezla. Pharmaceutical company Sandoz argued that several claims in the three patents were apparently invalid.
The legal battle began after Sandoz filed for multiple patents to manufacture and market generic versions of Otezla. According to Amgen’s 2022 financial results, the company earned about $2.3 billion in sales of its psoriasis drug. The company bought the drug from Celgene in 2019 for $13.4 billion.
Sandoz has appealed the district court’s ruling that both the ‘638 and ‘101 patents are not invalid. Pharmaceutical companies argued that the district court erred in the ‘638 patent decision by failing to find a reasonable expectation that the mixture could be isolated. In the ‘101 patent decision, Sandoz said the court’s holding that the priority date of the Amgen patent was his March 2002 was erroneous.
Amgen also appealed the district court’s ruling on the ‘541 patent, alleging that the district court erred in holding that the dosing schedule was invalid for obviousness.
The charm of sand
In its discussion of the ‘638 patent, the CAFC said it left the decision to experts on each side. The District Court and the Court of Appeal found Amgen’s expert testimony more persuasive.
Additionally, the CAFC writes:Schaefer’s [an inventor of the ‘638 patent] Reliable testimony is…sufficient to establish the existence of an unexpected result, and thus to support a finding of nonobviousness. ”
“Unexpected results” were key to the CAFC’s determination that the ‘638 patent was nonobvious. This patent relates to pharmaceutical compositions of drugs, including oral formulations and dosage forms. Dr. Schafer found that he found a 20-fold difference between “apremilast alone and apremilast with a racemic mixture”.
“As shown in the present case, a difference of 20 times is sufficient to support a finding of unexpected results, where a difference of 2 times would otherwise have been predicted by the skilled craftsman. “Claim 3 and 6 of the ‘638 patent would not have been obvious,” the Court of Appeals wrote.
In the case of the ‘101 patent, the Federal Circuit agreed with the district court that Sandoz did not provide evidence to prove that the 2002 application did not disclose a crystalline form of a drug for treating psoriasis.
“Sandoz did not produce experimental results indicating that Example 2 of the ‘515 provisional application did not produce crystalline form B of apremilast,” the CAFC found.
Amgen Cross Appeal
Amgen has attempted to appeal the district court’s ruling regarding the invalidity of the ‘541 patent. If the patent were found to be valid, Sand would have been barred from making Amgen’s generic drug until 2034.
The patent relates to a drug dosing schedule, and Amgen argued that the district court erred in analyzing the gist of the invention rather than the claimed invention. The pharmaceutical company continued its appeal, arguing that the district court failed to prove that the skilled craftsmen had good cause to pursue the alleged schedule.
Sandoz, on the other hand, argued that dose changes and scheduling were routine for those skilled in the art.
Ultimately, the Federal Circuit again upheld the district court’s holding that Amgen’s patent claims were self-evident and invalidated the patent.
Despite losing a cross-appeal, Amgen hailed a victory by upholding the district court’s ruling.
“Today’s ruling affirms a permanent injunction issued by the district court barring Sandoz and Zydus from manufacturing, using, selling, offering to sell, or importing each of the generic versions of Otezla until February 2028. It confirms,” Amgen wrote in a press statement.
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Author: Bill Perry
