T 0122/23 - Patentability over clinical trial protocol (no)

Key points

• "Document D7d describes a protocol for a phase III randomized controlled trial for the use of rifaximin in preventing hepatic encephalopathy. According to the protocol the trial was to evaluate the efficacy and safety of rifaximin given 550 mg twice daily as compared to placebo, optionally with concomitant use of lactulose, during a period of 6 months in subjects who are in remission from demonstrated hepatic encephalopathy."
• "The phase III clinical trial disclosed in document D7d only differs from the subject-matter of claim 1 of the main request in that document D7d does not report the actual effectiveness of the described treatment in decreasing the hepatic encephalopathy breakthrough episodes." (emphasis added throughout)
• Of course, claim 1 does not recite results reporting the actual effectiveness of the treatment. That is the "legal magic" of second medical use claims.
• Regarding obviousness: "The Board considers that the mere fact that document D7d reports the protocol for the evaluation of the efficacy and safety of rifaximin with optionally lactulose in a phase III clinical trial does not by itself provide the skilled person with a reasonable expectation of success of the trial."
• "The assessment of inventive step starting from document D7d therefore crucially depends on the question whether the skilled person had in view of the prior art, in particular having regard to the available information on the nature of the products under investigation and the condition to be treated, a reasonable expectation that the use of rifaximin with concomitant lactulose therapy would be effective in decreasing the risk of hepatic encephalopathy breakthrough episodes."
  
  
• "The Board considers that the tolerability, the clinical efficacy in treatment of hepatic encephalopathy and the efficacy in reducing ammonia-producing bacterial flora of the treatment with rifaximin combined with lactulose described in document D9 provided the skilled person with a reasonable expectation of success regarding the prevention of breakthrough episodes of hepatic encephalopathy under investigation in the trial of document D7d."
• "Document D9 reports the results from an open-label study indicating clinical efficacy and tolerability of the administration of rifaximin at a dose of 1200 mg/day in combination with lactulose during 15 consecutive days in the treatment of hepatic encephalopathy. "
• " The patent proprietor's argument, that due to its open-label set-up and taking account of the significant placebo effect in the treatment of hepatic encephalopathy the study in document D9 did not convincingly demonstrate the efficacy of the described treatment, is not considered persuasive." (follows some detailed reasoning)
•  "The results reported in document D9 are in line with the reports and reviews in documents D4, D5, D8, D14, D23, D4, D30, D31 and D52 regarding the practical utility of lactulose and rifaximin. The Board does therefore not consider that the lack of placebo-controlled evidence of the efficacy of rifaximin and lactulose in document D9 affects the reasonable expectation of success of the long-term treatment under investigation in document D7d based on document D9."
• "The Board has therefore concluded that the subject-matter of claim 1 of the main request does not involve an inventive step (Article 56 EPC)."
  
  
   

EPO 

The link to the decision can be found after the jump.

https://www.epo.org/en/boards-of-appeal/decisions/t230122eu1