Patent decision

BL number

O/125/02

Concerning rights in

GB 2270261 B

Hearing Officer

Mr S N Dennehey

Decision date

18 March 2002

Person(s) or Company(s) involved

Vetrapharm Limited and Alpharma; Vericore

Provisions discussed

PA.1977 1(1)(a), 1(1)(b) and 72

Keywords

Novelty, Revocation

Related Decisions

None

Summary

Vetrapharm Ltd and Alpharma sought revocation of the patent which concerned a second medical use of a pyrethroid for the treatment of sea lice infestation in sea water fish, such as salmon, on the grounds of lack of novelty and inventive step.

On a matter of construction it was decided that the term pyrethroid encompassed both pyrethrum which is a natural substance and synthetic pyrethroids based on expert evidence and extrinsic documents. Consequently earlier experiments using pyrethrum to delouse salmon destroyed the novelty of the invention. The disclosure of these experiments was considered enabling even though they may not have been sufficiently effective for commercial application.

The invention was also found to lack an inventive step, even on the basis of a narrow meaning of pyrethroid, it being obvious to delouse salmon using pyrethroids in light of the earlier experiments involving pyrethrum. The skilled person would have thought of using a synthetic pyrethroid instead of pyrethrum because there was a reasonable expectation that routine experimentation would establish a therapeutic dose (ie. one toxic to lice but not fish) for synthetic a pyrethroid as it had for pyrethrum. The patent was therefore revoked in its entirety.