The Court of Appeal recently heard a case relating to Genentech's patent, which claimed the use of human vascular endothelial growth factor (hVEGF) antagonists for the treatment of non-cancerous diseases which are characterised by excessive blood vessel growth (neovascularisation or angiogenesis).  Regeneron and Bayer sought a declaration of non-infringement and revocation of the patent based on construction, novelty, inventive step, and sufficiency arguments, all of which were rejected at first instance.  Regeneron and Bayer then appealed.

The main issue discussed in the appeal proceedings was that of sufficiency.  The appellants argued that the patent's scope was too broad as it covered a wide range of antagonists and diseases.  It would therefore impose an undue burden on the skilled person to identify which diseases can be treated with which antagonists.  The judge held that if it is plausible or credible that the invention will work over substantially the entire scope of the claims, the claims can be defined in general terms.  This was found to be the case in the present proceedings due to the common thread of angiogenesis between the claimed disease states and so the scope of the claims was considered appropriate.  However, if only a few embodiments would work, these must be claimed specifically.  As for evidence to support the claims, it was held that there is no need to report results of clinical trials, but the evidence must show that the therapeutic effect is plausible.

Further, the fact that regulatory approval would be hard to obtain was deemed to be irrelevant, as it takes into account factors such as side effects, which are not considered by the patent.  The appellants also cited various diseases as not being treated by the invention.  However, it was highlighted that it was only the angiogenic component that needed to be treated.  There was no evidence that there was no effect on the angiogenic component of the cited diseases, despite other components not being affected.  When discussing the construction of the claim, the judge found that angiogenesis must contribute to the pathology of the diseases covered, but need not be the cause of it.  This construction also meant that the skilled person would be able to easily identify the diseases covered by the claims.

Finally, it was argued that the patent was insufficient if it extended to the allegedly infringing molecule (a chimeric molecule demonstrating high affinity and improved pharmacokinetics), as production of such molecules would require undue effort and is not described in the patent.  However, it was held that the skilled person would have regarded chimeric molecules as variants falling within the scope of the claim.  It was emphasised that a claim for a broad invention could cover embodiments that may be invented in the future and which may have further advantageous properties.  The allegedly infringing molecule was such an embodiment as it encompassed the technical contribution of the claimed invention by binding VEGF and inhibiting its biological activity, despite requiring in itself a good deal of ingenuity.

The appellants also raised novelty and inventiveness objections over a document that discussed in vivo assays using VEGF antibodies and disclosed that the VEGF antibodies "may have therapeutic potential."  However, the judge held that the document did not disclose a therapeutic effect of the antibodies, or clear and unmistakeable directions to perform the invention.  Further, while the prior art suggested that VEGF may have therapeutic applications, it was disclosed as one of many factors being investigated.  The document also disclosed the antibodies as a research tool and so gave no reasonable expectation of success of using such antibodies therapeutically.

The claims were therefore found to be novel and inventive.  The appeal was dismissed and the patent was found to be valid and infringed on all counts.

This report comes from European Patent Attorneys at WP Thompson & Co., 55 Drury Lane, London UK.  Further details and commentary can be obtained from Gill Smaggasgale, a partner at the firm.