Five minutes with… Penny Gilbert


Five minutes with… Penny Gilbert

The fallout from the landmark Regeneron v Kymab is still being weighed by the UK life sciences community.

In part one of a two-part special LSPN Connect, panel of five lawyers involved in the Supreme Court proceedings discussed the background to the case and what happened in court (watch part one here).

This week, the group will meet again to discuss the wider ramifications, including cross border comparisons and what it means for litigation in the UK. 

LSIPR caught up with part-one panellist Penny Gilbert, partner at Powell & Gilbert, to find out more…

LSIPR: Do you think the outcome of Regeneron v Kymab will set a precedent for future judgments in the UK?

Penny Gilbert: As a decision from the UK Supreme Court, the case will be material to the assessment of sufficiency in the UK. In fact, the case has already been reviewed and applied in the first decision from the patents court in 2021, Illumina v MGI.

In that case, Justice Birss noted that once the concept of a relevant range is properly understood, for the purpose of assessing sufficiency, when he said: “it will be an unusual case in which the kind of ordinary descriptive or functional language one sees in most patent claims will be regarded as a relevant range in the Regeneron sense.”

So although Regeneron sets a precedent, it may have little impact on how sufficiency is assessed.

What do you think is the key takeaway?

The case highlights the difficult decision on when to file, and how much experimental work needs to be carried out before filing, in order to bolster the specification so that it is less vulnerable to validity challenges.

Careful consideration also needs to be given to the breadth of claim that is pursued and whether it can be supported by the patent disclosure, bearing in mind the technical contribution made to the art by the particular invention.

What are the positives and negatives of filing biotech patents early?

Early filing is important in crowded technical fields, where there is likely to be a race to get the earliest priority date. Nevertheless, filing too early without sufficient information on how to work the invention, or including support for its potential uses, may be counter-productive and leave the patent open to later validity challenges. It’s a difficult balance to strike.

LSPN Connect is the membership programme for the Life Sciences—to watch this session and for more information on joining, visit

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biotech, sufficiency, patents, Regeneron, Kymab, supreme court