Instructing expert witnesses: pharma patents case a lesson for lawyers

Nicole Jadeja of Pinsent Masons, the law firm behind Out-Law, said the importance of the issues were emphasised by the High Court in a case involving a dispute between businesses that have already developed or are developing rival treatments for anaemia and related conditions.

The case centred on the validity of patents owned by FibroGen and whether rival companies Akebia Therapeutics and Otsuka Pharmaceutical infringed those patents. Akebia and Otsuka are engaged in clinical trial testing for a rival product called vadadustat which they are seeking to launch to market.

Lord Justice Arnold ruled in favour of Akebia and Otsuka, deeming that five of FibroGen's six patents are invalid. In relation to the sixth patent, the judge held that FibroGen's patent is valid but that Akebia and Otsuka do not infringe the rights FibroGen enjoy under that patent.

In his judgment, Lord Justice Arnold reflected on the contributions to the arguments advanced on both sides by expert witnesses and the way they had been instructed by the parties.

He said the expert witnesses in the case had been "let down" by those who had instructed them and found unfairness in a way one of the witnesses had been cross-examined, and added that attempts should be made to minimise the views of experts on the validity of patents being coloured by the benefit of hindsight.

Lord Justice Arnold reiterated a view he expressed in an earlier case that "the lawyers who instruct expert witnesses bear a heavy responsibility for ensuring that an expert witness is not put in a position where he can be made to appear to have failed in his duty to the court even though he conscientiously believes that he has complied with that duty".

The judge also expressed his regret that a "technical primer" had not been prepared by the parties to help explain "moderately complex areas of science" that were at issue in the case. He said technical primers should be "regarded as mandatory in Category 4 and 5 cases" in future "unless there are good reasons to the contrary". The technical difficulty rating of patent cases in England and Wales is relevant to the time estimated for judges to read case papers and for trials to be conducted, and therefore can impact on the time and cost of litigation to the parties involved.

"We are increasingly seeing the courts having to grapple with complex technology in the life sciences space and this case is no exception," said Nicole Jadeja of Pinsent Masons. "It is imperative that lawyers take steps to assist the judge in understanding the technology, which can only be of assistance to their client’s case."

"This case also demonstrates the importance of properly instructing expert witnesses, and the need to do so in a way that will minimise hindsight.This is not a new issue but one which raises several challenges for those instructing experts and which needs to be carefully navigated. The judge gave a strong warning that a failure to properly instruct experts is not acceptable and he would have no hesitation in taking steps to enforce professional standards if practitioners failed to adhere to the standards expected of them," she said.

Additional reporting by Charlie Davies of Pinsent Masons, the law firm behind Out-Law.